(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "Effects of amount of food reinforcement on fixed-interval-induced attack in pigeons"

EFFECTS OF AMOUNT OF FOOD REINFORCEMENT ON 
FIXED-INTERVAL-INDUCED ATTACK IN PIGEONS 



By 
RAYMOND C. PITTS 



A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL 

OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT 

OF THE REQUIREMENTS FOR THE DEGREE OF 

DOCTOR OF PHILOSOPHY 

UNIVERSITY OF FLORIDA 

1989 



ACKNOWLEDGEMENTS 

I would like to thank the members of my supervisory 
committee, Drs. E. F. Malagodi, M. N. Branch, B. A. Iwata, 
H. S. Pennypacker, D. J. Stehouwer, and W. D. Wolking, for 
all their committee-related behavior. I also want to thank 
Kevin Jackson, Ron Allen, Anne Sicignano, and Jeff Kupfer 
for their conceptual input. Special thanks go to Dr. 
Malagodi for serving as my chair, my advisor, my teacher, 
and my friend. Also, I would like to extend my appreciation 
to Dr. Branch for the generous use of his computer 
equipment. Finally, very special thanks go to the most 
important person in my life, Christine Hughes, for helping 
me in every possible way. 



11 



TABLE OF CONTENTS 

ACKNOWLEDGEMENTS ii 

ABSTRACT iv 

GENERAL INTRODUCTION 1 

Literature Review 4 

The effects of schedule variables on induced 

behavior 4 

The effects of consequence variables on 

induced behavior 8 

Summary and conclusions 10 

Theoretical Overview 11 

Falk's adjunctive behavior hypothesis .... 11 
Notions that schedules possess aversive 

properties 15 

Staddon's motivational hypothesis 16 

Killeen's concept of arousal 20 

Summary and conclusions 2 3 

The Purpose of the Present Experiment 2 5 

EXPERIMENT 1 26 

Introduction 2 6 

Method 28 

Subjects 28 

Apparatus 28 

Procedure 3 

Results and Discussion 33 

EXPERIMENT 2 59 

Introduction 59 

Method 60 

Subjects 60 

Apparatus 61 

Procedure 61 

Results and Discussion 62 

GENERAL DISCUSSION 75 

REFERENCES 94 

BIOGRAPHICAL SKETCH 102 



111 



Abstract of Dissertation Presented to the Graduate School 

of the University of Florida in Partial Fulfillment of the 

Requirements for the Degree of Doctor of Philosophy 

EFFECTS OF AMOUNT OF FOOD REINFORCEMENT ON 
FIXED-INTERVAL-INDUCED ATTACK IN PIGEONS 

By 

RAYMOND C. PITTS 

December, 1989 

Chair: Dr. E. F. Malagodi 
Major Department: Psychology 

Keypecking by pigeons was maintained on a chained 
fixed-interval t fixed-ratio one schedule of food 
presentation. Attacks toward a restrained and protected 
conspecific were recorded. In the first experiment, the 
amount of food presented per interval was manipulated across 
phases by varying the number of repetitions of the fixed- 
ratio one schedule required in the terminal component of the 
chain. Levels of attack during the fixed-interval component 
increased monotonically as a function of amount of food 
presented in the terminal component. In the second 
experiment, a multiple schedule was used in which two 
different food amounts alternated within each session. For 
both pigeons in this experiment, more attack was observed 
during the component that delivered the larger amount of 



IV 



food per interval. The results of these experiments are 
discussed in terms of a number of different theoretical 
frameworks, including views that attack is properly 
considered as "adjunctive behavior," notions that 
intermittent schedules possess aversive properties, 
conceptualizations of attack as an example of "interim 
activities," concepts that suggest that induced attack 
results from "arousal," and suggestions that induced 
behaviors can be conceptualized within the context of an 
"opponent-process" theory of motivation. It is suggested 
that, although the results of the present study are relevant 
to each of these views, further analyses are required before 
an integrated picture of induced attack and other induced 
behaviors can emerge. 



GENERAL INTRODUCTION 

Since Ferster and Skinner's (1957) extensive survey of 
schedules of reinforcement, numerous empirical studies and 
theoretical discussions of the effects of various schedules 
have been published by other investigators (see Zeiler, 1977 
for a review) . Indeed, it may be said that the study of 
reinforcement schedules became the dominant research area in 
the experimental analysis of behavior during the next two or 
three decades. The primary focus of these empirical and 
theoretical analyses has been examination of the effects of 
schedule variables on rates and temporal patterns of ongoing 
operant behavior maintained by intermittently presented 
reinforcers. 

Some experimenters studying intermittent schedules, 
however, began to notice that powerful and ubiquitous 
"schedule-effects" were not restricted to behaviors which 
produced, or closely preceded, the scheduled reinforcer. 
Falk (1961) , for example, discovered a most interesting and 
reproducible sequence of behavior in rats when lever 
pressing was maintained by a variable-interval (VI) schedule 
of food presentation. Rates and patterns of lever pressing 



2 

were typical for VI schedules in that a moderate and steady 
rate of responding was maintained. In addition to lever 
pressing, and eating the food pellets as they were 
delivered, the rats regularly drank from a water bottle that 
was continuously available in the chamber. While it was not 
especially surprising that the rats drank from the bottle 
during lengthy experimental sessions, a number of 
characteristics of drinking were unexpected, yet were quite 
orderly. The features of drinking (and of the conditions 
under which drinking occurred in this experiment) that 
captured Falk's attention and became the focus of a large 
number of subsequent experiments were a) while the rats were 
food-deprived, they were not water-deprived, b) drinking 
followed each and every delivery of a food pellet, c) the 
rats consumed excessive amounts of water — approximately four 
times the amounts normally consumed per twenty-four hour 
period in the home cages, and d) drinking decreased 
dramatically or ceased altogether during various "control" 
procedures during which food was not intermittently 
scheduled. Subsequent experiments determined that such 
"adjunctive" or schedule-induced drinking could not be 
viewed as superstitious behavior controlled by accidental 
reinforcement of licking by food presentation (see Falk, 
1971) . 

In a related experiment, Gentry (1968) demonstrated 
that when keypecking by food-deprived pigeons was maintained 



on a fixed-ratio (FR) schedule of food presentation, the 
pigeons reliably attacked a restrained conspecific located 
at the rear of the experimental chamber. The attacking 
observed by Gentry (1968) was similar to the drinking 
observed by Falk (1961) in that attacking a) was typically 
observed to occur in periods just after food delivery, 
b) followed a large proportion of food presentations, c) did 
not occur under conditions when food was not intermittently 
presented, and d) apparently was not adventitiously 
reinforced by food presentation. In both Falk's (1961) and 
Gentry's (1968) experiments, a regular temporal sequence of 
behavior was observed: following delivery of food, the 
subjects engaged in a bout of induced activity (pigeons' 
attacking and rats' drinking) which ceased rather abruptly 
and was followed by operant behavior (pigeons' keypecking 
and rats' lever pressing) until the next food delivery. 

A rather wide range of other induced behaviors has been 
found to occur following food presentation during various 
intermittent schedules of reinforcement. These include pica 
in rats and monkeys, aggression in monkeys, wheel-running in 
rats, drinking in pigeons, escaping from stimuli associated 
with positive reinforcement in pigeons and rats, and air 
licking in rats (see Falk, 1971; Staddon, 1977; 
Wetherington, 1982) . Investigations over the past 2 5 years 
have shown that these schedule-induced behaviors occur in 
several species, are induced by a variety of intermittent 



4 
schedules, and are induced by various events (e.g., food, 
water, and shock) when scheduled intermittently. 

Literature Review 

Much of the research on schedule-induced behavior can 
be divided into two general categories: a) experiments 
investigating the effects of schedule variables , such as 
parameter value of a given schedule or schedule type, and b) 
experiments investigating the effects of variables 
associated with the scheduled event itself, or what might be 
called consequence variables . Included in this class of 
variables are deprivation of, and amount of the scheduled 
reinforcer. 
The effects of schedule variables on induced behavior 

Most experiments in this category have focused on 
examination of induced behavior as a function of schedule 
parameter, such as the inter food interval on time-based 
schedules, or the response requirement on ratio schedules. 
The relationship between induced behavior and interfood 
interval on time-based schedules depends upon the particular 
induced behavior and on its measurement. In studies of 
induced drinking during fixed-interval (FI) , variable- 
interval (VI) , and fixed-time (FT) schedules of food 
presentation, total water consumption is an inverted U- 
shaped function of the interfood interval (Bond, 1973; Falk, 
1966; Flory, 1971; Hawkins, Shrot, Githens, & Everett, 1972; 



5 

Wetherington, 1979) . This inverted U-shaped, or bitonic, 
function relating induced drinking to interfood interval has 
also been reported with the number of licks per session 
(Flory, 1971; Wetherington, 1979), the amount of time 
drinking per pellet (Wetherington, 1979) , and the percentage 
of intervals containing drinking (Allen & Kenshalo, 1976; 
Segal, Oden, & Deadwyler, 1965). However, when drinking 
induced by an FT schedule of food presentation is measured 
as the rate of water consumption and as the rate of licking, 
both are a decreasing function of interfood interval 
(Wetherington, 1979) . These differences in relations 
between drinking and interfood interval as a function of 
measurement illustrate the importance of measurement 
selection, its effects on experimental results, and on 
theoretical interpretations derived from them. For detailed 
discussions of measurement issues in schedule-induced 
behavior, see Allen, Sicignano, Webbe, & Malagodi (1980) , 
Webbe, DeWeese, & Malagodi (1974), and Wetherington (1979, 
1982) . 

Results of experiments examining induced attack as a 
function of interfood interval are more consistent across 
measures than those of induced drinking. Attack by pigeons 
induced by FI, FT, and response-initiated FI schedules of 
food presentation show a bitonic relation to interfood 
interval similar to that seen with induced drinking (Cherek, 
Thompson, & Heistad, 1973; DeWeese, Webbe, & Malagodi, 1972; 



6 

Flory, 1969b) . This bitonic function was observed with all 
measures of induced attack employed in these experiments, 
which included rate of attack, attacks per reinforcement, 
percent of intervals with attack. 

Schedule-induced "escape" by pigeons has also been 
observed during fixed-interval schedules of food 
presentation (Brown & Flory, 1972) . In this experiment, 
pecks on one key produced food according to an FI schedule, 
while pecks on a second key produced an "escape" period with 
a visual stimulus change. These investigators reported a 
bitonic relation between measures of escape (escape rate and 
percent of session during escape stimuli) and inter food 
interval for most subjects. Note, however, that the fixed- 
interval timer did not operate during the stimulus change 
periods and, thus, these periods may not have functioned as 
true escape periods. 

The effects of ratio parameter on schedule-induced 
behavior most often has been examined in studies of induced 
attack in pigeons and monkeys, and induced escape in pigeons 
and rats. As with studies on induced drinking during time- 
based schedules, the results of experiments on the effect of 
ratio size on induced attack depend critically upon how 
attack is measured. When induced attack is examined in 
fixed-ratio (FR) (Flory, 1969a; Hutchinson, Azrin, & Hunt, 
1968; Knutson, 1970; Webbe et al . , 1974), variable-ratio 
(VR) (Webbe et al., 1974), and regressive-ratio (Reg R) 



7 
(Allen et al., 1980) schedules of food presentation, most 
measures tend to increase monotonically as a function of 
ratio size. These measures include total number of attacks 
(Hutchinson et al., 1968; Knutson, 1970), total number of 
attack episodes (Flory, 1969a) , time spent attacking 
(Knutson, 1970), attacks per interval (Webbe et al., 1974), 
and proportion of intervals containing attack (Flory, 1969a; 
Webbe et al., 1974). However, when rate of mirror-pecking 
is measured as a function of ratio size in PR schedules of 
food presentation, an inverted U-shaped function is observed 
(Cohen & Looney, 1973) . 

When keypecking or lever pressing is maintained on 
ratio schedules of food presentation, pigeons and rats will 
respond on a second operandum when these responses produce 
escape, or time-out, periods. During these escape periods, 
responses usually do not count toward the completion of the 
ratio requirement. Subjects escape more frequently, 
following more food presentations, and spend more time in 
time-out periods as a function of ratio size in FR and 
progressive-ratio (PR) schedules (Appel, 1963; Azrin, 1961; 
Dardano, 1973; Thompson, 1964). 

Relatively few studies have examined induced polydipsia 
under ratio schedules of food presentation. Total water 
intake and total licks are an increasing function of the 
response requirement on FR schedules (Burks, 1970; Carlisle, 
1971) . Note that, unlike studies of induced attack and 



8 
induced escape, the effects of ratios of over 100 have not 
been examined in studies of induced drinking. 
The effects of consequence variables on induced behavior 

The literature relating consequence variables to 
schedule-induced behavior is less extensive than the 
literature on schedule variables. Data on consequence- 
variable effects have come nearly exclusively from 
experiments on schedule-induced polydipsia in rats. 
Published reports of examinations of these variables on 
other induced behaviors and in other species are 
conspicuously lacking. 

When studied as a function of food deprivation, induced 
drinking is usually an inverse function of body weight 
(e.g., Falk, 1969; Freed & Hymowitz, 1972; Roper & Nieto, 
1979; Wayner & Rondeau, 1976). One study examining the 
effect of this variable on schedule-induced attack in 
pigeons reported a similar inverse relation (Dove, 1976) . 

A number of studies have examined the relation between 
induced drinking and the amount (or magnitude) of food 
reinforcement. A majority of these experiments have 
reported increases in measures of induced drinking as a 
function of food amount (e.g., number of pellets) (Bond, 
1973; Couch, 1974; Flory, 1971; Hawkins et al . , 1972; 
Rosellini & Burdette, 1980; Yoburn & Flory, 1977). Some 
studies, however, have found that induced drinking decreases 
(Falk, 1967; Freed & Hymowitz, 1972) or does not change 



9 

systematically as a function of food amount (Keehn & 
Colotla, 1971) . One set of experiments reported that the 
effects of amount of food reinforcement on schedule-induced 
drinking depended upon whether comparisons were made within 
or between experimental sessions (Reid & Dale, 1983; Reid & 
Staddon, 1982) . Larger amounts of food attenuated drinking 
when comparisons were made within sessions, but augmented 
drinking when comparisons were made between sessions. 

Issues surrounding measurement of induced behavior are 
not only important in examinations of schedule variables, 
but are also important in experiments on food amount. Falk 
(1967) reported that when lever pressing was maintained on a 
VI-1 min schedule of food presentation, two pellets per 
interval resulted in lower total water intakes than did one 
pellet per interval. However, in this experiment, the 
number of pellets per session was constant across 
conditions, resulting in shorter sessions and fewer 
intervals per session during the two-pellet condition. When 
these data were recalculated as ingestion rates, drinking 
was higher during the two-pellet condition in four of six 
possible comparisons (Hawkins et al., 1972). 

The relation between schedule-induced attack and the 
amount of food has not been extensively studied. One 
investigation found that the larger of two food magnitudes 
induced more attack in pigeons when food was presented on FT 
schedules (Flory, Robinson, & Dunahoo, 1988) . Investigations 



10 
of induced attack as a function of a range of reinforcement 
amounts have not been reported. 
Summary and conclusions 

As mentioned above, the effects of schedule 
manipulations depend upon the particular induced response 
studied and upon how that response is measured. In general, 
however, most experiments relating induced drinking and 
induced attack to interfood interval on time-based schedules 
of food presentation have revealed an inverted U-shaped, or 
bitonic, function. In contrast, most experiments of induced 
behavior during ratio schedules have shown monotonically 
increasing levels of induced responding as a function of 
ratio parameter. The exceptions to these general findings 
are usually when rates of induced behavior are used as 
dependent variables (see section entitled The effects of 
schedule variables on induced behavior ) . 

The effects of consequence variables have usually been 
studied on induced polydipsia in rats. In general, levels 
of behavior induced by intermittent schedules of food 
presentation increase as a function of deprivation level and 
as a function of food amount, although a few studies have 
reported contrasting effects of food amount. 

It is tempting to conclude that the data reviewed above 
on consequence variables imply that operations that increase 
the reinforcing efficacy of the scheduled event result in 
increases in levels of induced activity. It is contended 



11 
here that such a conclusion would be premature. More 
systematic and comprehensive analyses of the effects of 
consequence variable on different induced behaviors, in 
different species, and in different schedule contexts must 
be undertaken in order to provide a more complete 
characterization of the effects of these variables on 
schedule-induced behavior. 

Theoretical Overview 

Several theoretical frameworks have been offered in 
attempts to clarify the nature of the processes involved in 
schedule-induced behavior. These include 1) the adjunctive 
behavior hypothesis proposed by Falk, 2) the view that 
intermittent schedules possess aversive properties, 3) 
Staddon's motivational hypothesis, and 4) Killeen's concept 
of arousal. These views differ markedly in their structure 
and in specific predictions derivable from them and, 
therefore, will be discussed separately and in detail. 
Falk's adjunctive behavior hypothesis 

One conceptualization of schedule-induced behavior was 
proposed by Falk (1969, 1971). When early attempts to 
reconcile the excessiveness of induced polydipsia with known 
regulatory mechanisms failed, attention turned toward it's 
environmental determinants. Difficulties in the application 
of principles of operant or respondent conditioning as 
explanations of induced behavior led Falk (1971) to propose 



12 
the existence of a new class of behavior. Noting a number 
of similarities among induced activities (discussed above) , 
Falk suggested that schedule-induced drinking, schedule- 
induced attack, and other schedule-induced activities are 
properly considered members of a class of "adjunctive" 
behaviors. These behaviors are adjunctive in that they 
occur as by-products of a schedule of reinforcement that 
maintains some other response, and are considered similar to 
the displacement activities observed and discussed by 
ethologists. Displacement activities are described as 
occurring in situations where an animal "under high drive 
conditions" is engaged in some sort of consummatory behavior 
and is prevented from continuing this behavior (Falk, 1971) . 
Falk points out that these are the conditions producing 
adjunctive behavior: a food deprived animal engaged in 
eating is prevented from continuing this behavior by the 
imposed intermittent schedule of food presentation. 

The bitonic function frequently observed in studies 
relating induced responding to schedule parameter is central 
to Falk's interpretation. He proposes that intermittent 
presentation of food results in adjunctive behavior only 
when the schedule arranges a rate of food consumption within 
a certain "effective range." This "consummatory rate 
hypothesis" suggests that at high rates of food consumption 
(e.g., short interfood intervals) adjunctive responding is 
low. As consumption rate decreases (e.g., by lengthening 



13 
the inter food interval) , adjunctive behavior increases to a 
maximum until, at still lower consummatory rates, adjunctive 
behavior decreases (Falk, 1969, 1971). According to this 
view, the particular type of schedule is important only 
insofar as it arranges a particular consummatory rate. 

Data from those experiments demonstrating a bitonic 
function between rate of food presentation and measures of 
induced behavior, coupled with the similarities among 
induced activities listed earlier provide evidence in favor 
of Falk's view. In addition, Falk (1967) compared various 
combinations of interfood intervals and food amounts that 
programmed equal consummatory rates (e.g., VI 1 min with one 
food pellet per interval and VI 2 min with 2 pellets per 
interval) , and reported that the most reliable predictor of 
the total amount of schedule-induced drinking was the number 
of pellets presented per minute (Falk, 1967) . However, 
different session lengths (and hence, different total 
interfood intervals per session) were programmed during 
conditions that delivered two pellets. This feature 
severely handicaps definitive interpretation of these data 
(see General Discussion for a more detailed discussion of 
this study and the consummatory rate hypothesis) . 

Some studies, however, have reported data that are at 
odds with Falk's consummatory rate hypothesis. First, FR 
schedules have been found to induce more attack than 
response-independent schedules that program equal rates and 



14 
temporal distributions of food presentation (i.e., matched- 
time, or MT schedules) (Malagodi, Sicignano, & Allen, 1979). 
Second, some studies of induced drinking (Bond, 197 3) and 
induced attacking (Flory et al, 1988), comparing various 
combinations of interfood intervals and food amounts have 
failed to replicate Falk's (1967) results. Third, a number 
of studies have reported direct, monotonic increases in 
schedule-induced attack, escape, and polydipsia as a 
function of ratio size (See Literature Review) . Falk 
(1971) , has noted that data reported in studies on ratio 
schedules may represent only the ascending portion of the 
bitonic function relating adjunctive behavior to interfood 
interval (the descending portion if food rate is used as the 
independent variable) . However, subsequent data obtained on 
regressive-ratio (Reg R) schedules have reported a 
monotonically increasing function between schedule-induced 
attack and ratio size, even when interfood intervals on the 
larger ratios (over 100 minutes) far exceeded those 
previously shown to produce the descending portion of the 
bitonic function (Allen et al., 1980). The results of the 
experiments discussed above suggest that factors other than 
consummatory rate per se are important in the production and 
maintenance of schedule-induced behavior. 



15 
Notions that schedules possess aversive properties 

A second interpretation of schedule-induced behavior 
(particularly schedule-induced attack and escape) is offered 
by Azrin and his associates (Azrin, 1961; Azrin, Hutchinson, 
& Hake, 1966; Hutchinson et al., 1968), and others (Richards 
& Rilling, 1972) . The results of studies showing a direct 
relation between attack and response requirement in ratio 
schedules, in concert with data showing that attack is often 
generated by conditions that are normally escaped or 
avoided, such as electric shock presentation (Azrin, 
Hutchinson, & McLaughlin, 1965; Ulrich & Azrin, 1962), a 
physical blow (Azrin, Hake, & Hutchinson, 1965) , and 
extinction (Azrin et al., 1966; Kelly & Hake, 1970), suggest 
that intermittent schedules may possess aversive properties. 
In this view, periods of zero or low reinforcement 
probability in intermittent schedules are aversive, and the 
magnitude of aversiveness is partly determined by the 
response requirements of ratio schedules (Hutchinson et al., 
1968) . This interpretation is supported by studies showing 
that subjects will escape from schedules of positive 
reinforcement, that likelihood of escape is directly related 
to ratio size (Azrin, 1961; Appel, 1963; Thompson, 1964) and 
that more attack is induced by FR schedules than by MT 
schedules (Malagodi et al., 1979). Further support of this 
view derives from data that have reported more induced 
attack under an FR schedule of food presentation than under 



16 
an equal valued VR schedule (Webbe et al, 1974) . The 
occasional reinforcements that closely follow previous 
reinforcement periods on VR schedules might attenuate the 
aversiveness of the post-reinforcement periods. 

Although the notion that intermittent schedules possess 
aversive properties is compelling, data from some studies 
suggest that factors other than schedule aversiveness are 
involved in schedule-induced attack and in other schedule- 
induced behaviors. The bitonic relation frequently observed 
with induced behavior during time-based schedules and 
occasionally observed during ratio schedules is difficult to 
reconcile with the notion of schedule aversiveness. This 
relation suggests either an entirely different 
interpretation, or an amendment that addresses the 
decreasing portion of the function at longer interfood 
intervals. For example, it is possible that the ascending 
portion of the bitonic function on time-based schedules 
results from an increase in schedule aversiveness, and the 
decrease in this function at longer intervals reflects 
competition from other activities that emerge at these 
longer intervals (e.g., the "facultative activities" 
proposed by Staddon, 1977) . 
Staddon's motivational hypothesis 

A third theoretical approach has been offered by 
Staddon and his colleagues (Staddon, 1977; Staddon & Ayers, 
1975; Staddon & Simmelhag, 1971) . According to this 



17 
conceptualization, much of the research on schedule- 
controlled behavior has been governed by the tacit 
assumption that the effects of response-dependent 
reinforcement are somehow more fundamental than those of 
response-independent reinforcement. In Staddon's (1977) 
view, correlations between reinforcement, and temporal and 
stimulus variables are most important in determining the 
final pattern of performance on reinforcement schedules. If 
the way these variables act is to be understood, the 
response contingency so ubiquitous in operant conditioning 
experiments is an unnecessary complication. Therefore, most 
of the data offered in support of this position are from 
studies using response-independent food presentation. 

Staddon (1977) notes that periodic (and therefore 
intermittent) presentation of response-independent food 
results in an organized and stereotyped sequence of behavior 
(termed "schedule-induced behavior") . In this framework, 
adjunctive (or schedule-induced) and operant responses are 
all classified as schedule-induced behavior, with the 
distinction between them being their temporal location 
within the inter food interval. For Staddon, induced 
behaviors that emerge in the presence of, or are directed 
toward, stimuli that are predictive of food are called 
"terminal responses" and are what is traditionally studied 
as operant behavior. Induced behaviors that emerge at times 
when food is unlikely are called "interim responses" and are 



18 
what is traditionally studied as adjunctive or schedule- 
induced behavior. Thus, when intermittent reinforcement is 
programmed, observed keypecking by pigeons and lever 
pressing by rats are considered terminal responses, and 
schedule-induced attacking in pigeons and drinking in rats 
are considered interim responses. Each type of activity is 
seen as serving an adaptive function: terminal responses are 
related to the procurement and consumption of food, and 
interim responses serve to remove an animal from food 
situations at times when food is unlikely. Interim 
responses include schedule-induced drinking and attacking, 
and any number of activities observed to occur during the 
period shortly after food delivery (e.g., grooming, 
preening, wing flapping) (Staddon & Simmelhag, 1971) . 

Staddon (1977) suggests that all induced activities are 
critically dependent upon motivational factors. Two types 
of motivational variables are said to determine induced 
behavior: variables related to the scheduled reinforcer 
(e.g., deprivation, schedule, and amount) and variables 
related to the particular interim response (e.g., "thirst" 
if drinking is the interim response) . In studies on 
schedule-induced polydipsia, for example, induced drinking 
and food related responding (such as lever pressing) are 
related to food motivation in a similar way: "... the 
'hungrier' the animal during the terminal period, the 
'thirstier' he is during the interim period" (Staddon, 1977, 



19 
p. 139) . Thus, programming intermittent food presentation 
to a food-deprived rat is a motivational operation similar 
to depriving the rat of water and results in drinking at 
times when food delivery is unlikely. In this view, any 
operation that increases the reinforcing efficacy of food 
should similarly increase both terminal and interim 
responding, until a point is reached where the two 
activities are in direct competition, at which time the 
entire interfood interval is dominated by the terminal 
response. 

Staddon (1977) cites examples in which schedule-induced 
drinking is a direct function of food rate and food amount 
in support of his motivational hypothesis (see Literature 
Review) . Also presented are data replotted from Falk (1969) 
and Flory (1971) , originally reporting bitonic functions 
relating total water intake to interfood interval. When 
these data are plotted as water intake per minute and licks 
per minute as a function of food rate, both are 
monotonically increasing. It is not surprising that such a 
difference is seen when rate is used as a measure of induced 
activity. When the number of interfood intervals per 
session are constant (as is frequently the case in studies 
of induced behavior) , then session length is likely to 
decrease as schedule parameter is decreased (this must occur 
if interval schedules are used) . Thus, when induced 
behavior is measured as a rate, no change, or even a 



20 
decrease in total number of induced responses as schedule 
parameter is decreased can actually show a rate increase due 
to a decrease in size of the denominator. 

Recall that a number of studies have found that many 
measures of induced responding are bitonically related to 
interfood interval and are directly related to ratio size. 
Neither of these results is predicted from the view proposed 
by Staddon. Also, recall that Staddon ' s approach is 
predicated upon studies employing response-independent food 
presentation. Indeed, it has been asserted that the 
presence or absence of a response-requirement makes little 
difference in the amount or temporal placement of schedule- 
induced drinking (Burks, 1970; Falk, 1971; Segal et al . , 
1965; Staddon, 1977). Studies of schedule-induced attack, 
however, have shown that measures of attack may depend 
critically upon the number of responses required for food 
reinforcement (Allen et al., 1980), and that this relation 
is independent of interfood interval (Malagodi et al., 
1979) . These results also are not predicted from the 
theoretical framework offered by Staddon (1977) . 
Killeen's concept of arousal 

A fourth approach to schedule-induced behavior has been 
outlined by Killeen (Killeen, 1975; Killeen, Hanson, & 
Osborne, 1978) and suggests that these behaviors are a 
normally occurring part of an organism's repertoire, but 
"their rate of occurrence is excited to supernormal levels 



21 
by a heightened level of arousal" (Killeen et al., 1978, p. 
571) . This excessive arousal is produced by the periodic 
delivery of food (or other "incentives") , and each delivery 
contributes a small amount of arousal. With repeated 
deliveries, the arousal accumulates to a stable, 
"equilibrium," level that depends upon the size of the 
arousal, its rate of decay, and the time interval between 
arousal impulses. 

Killeen 's concept of arousal has been operationalized 
as measurements of "activity" taken by a set of 
microswitches located under floor panels of a standard 
pigeon operant-conditioning chamber. When food-deprived 
pigeons were exposed to fixed-time (FT) schedules of grain 
presentation at various interfood intervals, a specific 
pattern of activity within each interval was observed. Low 
levels of activity occurred immediately following food 
presentation, increased rather rapidly to a maximum at about 
one-quarter of the way into the interval, then gradually 
returned to low levels by the end of the interval (Killeen, 
1975; Killeen et al., 1978). The overall amount of activity 
was an increasing function of food rate, although the 
general pattern of activity within each interval was similar 
at all rates. 

Killeen et al. (1978) provide a mathematical model of 
arousal which suggests that the general pattern of activity 
observed when food is intermittently presented results from 



22 
the interaction of three processes: The first process is 
"arousal," which is maximal immediately after food 
presentation and decays very gradually throughout the 
interfood interval. The second process is termed "post- 
prandial inhibition" (". . . post-prandial behaviors and 
quiescence elicited by the offset of the previous incentive 
or the offset of a conditioned stimulus that indicates the 
immediate unavailability of other incentives." p. 372). 
Post-prandial inhibitions are maximal just after food 
presentation, and decay very rapidly. They compete with 
arousal and result in the low levels of activity observed 
just after food delivery; the rapid rise in activity is the 
result of the rapid decay in these inhibitions coupled with 
an existing high level of arousal. The third process is 
competition from terminal behaviors (such as keypecking or 
approaching the food hopper) ; competition from these 
terminal behaviors grows with the passage of time in the 
interfood interval, and results in an exponential decay of 
activity across the interval. 

Killeen et al. (1978) suggest that if the time 
between food presentations is short enough, arousal 
accumulates to such an extent that the "excessive" character 
of schedule-induced behavior is observed. This model also 
predicts a proportionality between activity (including 
schedule-induced behaviors) and rate of food presentation 
(Killeen et al., 1978). This prediction is confirmed in 



23 
some studies of activity (Killeen, 1975; Killeen et al., 
1978) and of schedule-induced behavior (Killeen, 1975; 
Wetherington, 1979) . Results of studies that show a bitonic 
relation between schedule-induced behavior and interfood 
interval are not predicted from Killeen 's model, nor are 
those that show a direct relation between induced behavior 
and ratio size. Killeen 's model also predicts that other 
variables which increase arousal should also increase levels 
of schedule-induced behavior. For example, more arousal is 
expected to result from increased food deprivation and from 
presentation of larger amounts of food. With a few 
exceptions, these predictions are generally confirmed by the 
data on consequence variables (see Literature Review) . 
Summary and conclusions 

It must be noted at this point that the four viewpoints 
presented above are not offered as an exhaustive list of 
interpretations of schedule-induced behavior. However, they 
represent four of the most popular and most cited 
theoretical conceptualizations in this research area. Other 
hypotheses, such as notions that induced behaviors are 
adventitiously reinforced by food presentation, or views of 
induced drinking as resulting from dry-mouth, have not 
survived experimental analyses (see Staddon, 1977) . 

The theoretical positions reviewed above suggest 
different relationships between induced behavior and 
schedule and consequence parameters. These viewpoints focus 



24 
on different induced activities, emphasize different 
characteristics of induced behavior, and rely upon different 
measurement procedures. Each of these conceptualizations 
are supported by results from some experiments but not by 
others. Thus, given the differences among these views, and 
given the disparities in experimental data, it becomes 
difficult to decide which of these views, or combination of 
views, is the most effective available account of schedule- 
induced behavior. The view taken here is that, although an 
extensive literature exists in schedule-induced behavior, 
not enough data are available to make conclusions regarding 
these, or any other, theoretical interpretations. Further 
analyses along a number of dimensions are required before 
useful theoretical statements about schedule-induced 
behavior can be made. For example, a complete picture of 
the effects of ratio size on induced drinking is lacking. 
The effects of relatively large ratios must be studied to 
determine whether the descending portion of the bitonic 
function so often observed at long interval durations is 
obtained. Also lacking are data on the effects of 
consequence variables on induced behaviors other than 
drinking. The absence of comprehensive analyses of these 
variables on induced attack and induced escape severely 
handicaps attempts at theoretical integration. 



25 
The Purpose of the Present Experiment 
The relative paucity of data on the effects of 
consequence variables on induced behaviors other than 
drinking is surprising, especially in view of a tradition of 
interspecies and interresponse replication among experiments 
on schedule variables. Systematic examinations of the 
relationship between the amount of food reinforcement and 
schedule-induced attack are noticeably absent. Therefore, 
the purpose of the present set of experiments is to provide 
a characterization of the function relating the amount of 
food reinforcement to schedule-induced attack over a 
relatively wide range of reinforcement amounts. It is hoped 
that data from these experiments will fill gaps in the 
existing literature and help provide an empirical basis for 
an eventual formulation of an adequate theoretical 
integration of schedule-induced phenomena. 



EXPERIMENT 1 

Introduction 

In Experiment 1, the amount of food was systematically 
manipulated across phases. Keypecking in pigeons was 
maintained by a two-component chained schedule of food 
presentation; the first component was an FI schedule and the 
second component was an PR 1 x n schedule. In the second 
component, completion of each FR 1 produced food. The 
amount of food per interval was examined by manipulating the 
number of consecutive FR I's (n) in the second component. 

The particular schedule of food presentation used in 
this experiment was selected for three reasons. First, an 
FI schedule was employed in hopes of generating intermediate 
levels of attack and, thus, providing a sensitive baseline 
against which to assess the effects of food amount. Ratio 
schedules of food presentation generally induce greater 
amounts of attack than do time-based schedules (Malagodi et 
al., 1979). Employing a ratio schedule in the present 
experiment may have resulted in near ceiling levels of 
attack and, therefore, may have masked the effects of food 
amount. Second, amount of food was varied by programming 
repeated FR I's in the terminal component, during which the 

26 



27 
food hopper was raised for fixed durations. This procedure 
was used, rather than simply raising the food hopper for 
varying durations, partly because of the capacity of the 
hopper. Because there was no a priori determination of the 
maximum food amount to be investigated, the possibility 
existed that, at very long hopper durations, the pigeons 
would empty the hopper prior to the end of the reinforcement 
cycle. Programming FR I's allowed the hopper to refill 
during the periods it was lowered. Also, the function 
relating amount of food consumed by pigeons to hopper 
duration may not be linear, but negatively accelerated, with 
an asymptote at approximately seven seconds (Epstein, 1981) . 
By arranging FR I's to produce the food hopper for a fixed 
duration throughout all conditions, and by varying the 
number of consecutive FR I's in the terminal component, it 
was reasoned that the actual amount of food consumed would 
more closely correspond to the value of the manipulated 
variable. Third, a chained schedule was used so that a 
distinct stimulus would be correlated with the beginning of 
and, most importantly, the termination of each period of 
food presentation. If, for example, a tandem rather than a 
chained schedule had been used, no programmed stimulus 
change would have accompanied the completion of the final FR 
1 in the terminal component. Under such conditions, levels 
of attack may have been influenced by a tendency to peck the 
key during the early portions of the fixed-interval. 



28 



Method 
Subjects 

Three adult male White Carneau pigeons ( Columba livia) , 
P-5626, P-7848, and P-1313 served as experimental subjects. 
Pigeons P-5626 and P-7848 had previous experience keypecking 
on concurrent VI schedules of food presentation. Pigeon P- 
1313 had a history of keypecking under VR and VI schedules 
of food presentation. Each subject was randomly paired with 
another bird that served as its target. Each bird was 
individually housed with water and health grit continuously 
available. Experimental subjects were maintained at 
approximately 80% of their free-feeding body weights. Food 
was continuously available for the target birds. 
Apparatus 

A 36 X 40 X 27 cm experimental space was enclosed in a 
sound-attenuating chamber. One wall was fitted with a 
standard BRS-Foringer three-key stimulus panel. The right 
key, located 8 cm from the right wall, could be 
transilluminated either white or red. Pecks with a force of 
at least 0.19 N against this key were defined as responses. 
The other two keys were dark and inoperative during this 
experiment. Two white houselights, each 10 cm from a side 
wall and 7 cm apart, were located above the stimulus panel. 
One white houselight was placed at the center of the back 
wall. A 4.5 X 5.5 cm aperture, into which a food hopper 



29 
could be raised, was located 15 cm below the center key. 
Reinforcement consisted of 4 s access to mixed grain, during 
which the houselights and key light were turned off and a 
white light illuminated the food hopper. 

The apparatus for restraining the target birds and for 
recording attack was similar to that described by Azrin et 
al. (1966) and Webbe et al. (1974), and was centered at the 
rear of the chamber, 40 cm from the stimulus panel. The 
restraint unit was a rectangular box constructed of clear 
Plexiglas and was mounted on a spring loaded metal plate. 
The unit was positioned with one end facing the experimental 
space. A microswitch was located under the metal plate such 
that displacements of the unit with a force that exceeded 
1.25 N activated the microswitch and were recorded as 
attacks. Visual inspection of early sessions via a video 
monitor revealed that at this force requirement, movements 
of the target did not activate the microswitch, but that 
most of the contacts by the experimental bird were reliably 
recorded. 

The target bird was restrained within the unit with 
foam cushions positioned below it and to its rear. An 
opening on the top of the unit closest to the experimental 
space allowed for the extrusion of the target bird's head, 
neck, and upper breast. A bib, constructed of synthetic 
white fur, was attached to the target so that the exposed 
breast region was entirely covered. An inverted, U-shaped, 



30 
Plexiglas shield was mounted 3 cm in front of the target 
bird's face and in the same plane as the rear wall of the 
chamber. This shield was positioned so the fur-covered 
breast of the target was exposed and the head of the target 
was protected. This arrangement allowed contacts of 
sufficient force of either the breast region or of the 
shield to activate the microswitch, while safeguarding 
against injury to the target bird. A diagram of the target 
restraining unit is provided in Figure 1. 

Continuous white noise was present to mask extraneous 
sounds, and a ventilation fan provided air circulation 
within the experimental space. All experimental events were 
programmed and recorded by electromechanical equipment 
located in a separate room. 
Procedure 

All experimental subjects had prior keypecking 
experience, so no initial training was necessary. Each 
subject was initially placed in the chamber for three one- 
hour sessions with its target bird present, the white 
houselights on, and no experimental contingencies in effect. 
The targets were then removed and each experimental pigeon 
was exposed to a chained fixed-interval t fixed-ratio 1 
times n schedule of food presentation (Ch FI t FR 1 x n) . 
On this schedule, in the presence of a white keylight, the 
first keypeck after t min had elapsed turned the keylight 
red, and each of the next n keypecks produced reinforcement. 



31 
After n grain presentations the keylight turned white and 
the cycle was repeated. The value of t was 4 min for P-5626 
and P-1313, and was 12 min for P- 7848.^ The initial value 
of n for each subject was one. After 30 sessions of fifteen 
intervals each under this schedule, the targets were 
reintroduced. The targets were present, and attack was 
recorded, during all remaining sessions of both experiments. 
Changeover contingencies were programmed such that in the 
presence of the white keylight keypecks within 5-s after an 
attack could not change the keylight to red, and in the 
presence of the red keylight could not produce grain. 

After measures (outlined below) of attack had 
stabilized under the n = 1 condition, the value of n was 
manipulated systematically across experimental phases. The 
values of n for each subject, the order of exposure to those 
values, and the number of sessions in all conditions of 
Experiment 1 are shown in Table 1. Pigeons P-7848 and P- 



^The FI value for P-7848 was initially 4 min. Manipulation 
of n from 1 to 24 under this schedule had little effect on 
measures of attack. Attack levels at all n values were 
relatively high for this subject. Because many studies have 
shown that attack induced by time-based schedules is 
bitonically related to inter-food interval, with peak levels 
often seen at intervals between 2 and 4 min (e.g. Cherek et 
al., 1973; DeWeese et al., 1972; Flory, 1969b), it was 
thought that attack in this subject may have been at ceiling 
levels at all n values. The fixed-interval duration for 
this subject was therefore increased to 12 min in hopes of 
producing a more intermediate attack level, and hence a more 
sensitive baseline against which to assess the effects of n. 
When the interval value was increased to 12 min at an n of 
1, mean attacks per interval with attack for the last 15 
sessions decreased from 118.7 to 64.2. 



32 
562 6 were exposed to an ascending series of n values from 1 
to 24, in increments of 8. The effects of n = 8 and n = 16 
were redetermined once for P-7848 and P-5626, respectively. 
The effects of n = 1 were redetermined twice for each bird. 
Pigeon P-1313 was exposed to n values of 1, 8, and 16. 
After 92 sessions under the n = 16 condition this subject 
was removed from the experiment because of illness. 

Sessions were usually conducted 5 days per week, except 
at larger values of n, when sessions were conducted every 
other day to insure that the body weights of the subjects at 
the beginning of each session were comparable across 
experimental conditions. Sessions were also conducted every 
other day during one of the exposures to n = 1 for both 
birds and during the second exposure to n = 8 for P-7848. 
These conditions are noted by a ^ in Table 1. Phases in 
which sessions occurred every other day at lower n values 
were conducted to assess the effects of n when a 
manipulation in this variable was not accompanied by a 
change in the schedule of sessions. Sessions terminated 
following completion of the fifteenth cycle, except at large 
n values, when the number of intervals per session for P- 
562 6 was reduced to 10 (noted by a ^ in Table 1) . 

Two measures of attacking served as dependent variables 
in the present experiment: the number of attacks per 
interval with attack and the proportion of intervals with at 
least one attack. These measures capture two different 



33 
characteristics of induced attack, the former depicts the 
average level of attack within an interval once attack has 
been initiated, and the latter estimates the tendency to 
initiate attack within a given interval. Measures such as 
these have been shown to be quite sensitive to manipulations 
of schedule parameter in both interval and ratio schedules 
(e.g., Allen et al., 1980; Wetherington, 1979). 
Experimental conditions were changed only when at least 15 
sessions had occurred with no systematic trends in both 
measures of attack, as determined by visual inspection of 
daily plots and cumulative records. 

Results and Discussion 
All birds attacked at low levels during the first two 
sessions during which no contingencies were programmed. 
Zero levels of attack were observed for all birds during the 
third session of this condition. Typical, positively 
accelerated temporal patterns of keypecking were seen for 
all birds during the FI component prior to the introduction 
of the target birds. When the target birds were introduced, 
each subject began to attack within the first session. 
Topographical characteristics of attack were similar to 
those reported in other studies (e.g. Dove, 1976) , primarily 
consisting of forceful pecking against the protective shield 
and the exposed bib. 



34 
Representative cumulative records of responding are 
presented in Figure 2 for P-7848, Figure 3 for P-5626, and 
Figure 4 for P-1313. For P-7848 and P-1313, records are 
shown from conditions when n was 1, 8, and 16; for P-562 6 
records shown are from conditions when n was 1 and 16. 
There are two records for each bird from each condition. In 
each set, keypecks stepped the response pen in the upper 
record, and attacks stepped the response pen in the lower 
record. These records illustrate several characteristics of 
responding that occurred in all birds. First, keypecking 
was generally characterized by a pause following 
reinforcement, followed by a transition to a moderately high 
rate. This transition was positively accelerated for P- 
7848, but more abrupt for P-5626 and P-1313. Both 
positively accelerated and "break and run" patterns of 
responding have been maintained under FI schedules of food 
presentation (e.g., Branch & Gollub, 1974; Ferster & 
Skinner, 1957) . Second, more attacks occurred when larger 
amounts of food were delivered per interval. Third, 
attacking usually occurred in bursts shortly after the last 
food presentation of an interval (i.e., upon illumination of 
the white keylight) and terminated abruptly sometime before 
the onset of keypecking. None of the birds attacked in the 
presence of the red keylight. Note that P-5626 occasionally 
attacked well into the fixed-interval (indicated by arrows 
in Figure 3) . Although this was not a consistent within- 



35 
session characteristic of attack, it did occur inter- 
mittently throughout the experiment with this subject. 
While most theorists reject the notion that induced behavior 
is an early response in a chain (Staddon, 1977) , it is 
possible that attacks occurring in later portions of the 
interval were part of a heterogeneous chain that terminated 
in keypecking. If such were the case, however, alternations 
between attacking and keypecking might have been expected to 
occur more frequently. 

Figures 5, 6, and 7 relate the number of attacks per 
interval with attack and the proportion of intervals 
containing attack for P-7848, P-5626, and P-1313, 
respectively, to the amount of food per interval, or n. 
Values shown are means from the last 15 sessions of each 
condition. For each subject, these measures of attack 
generally increased monotonically as a function of n. These 
functions can be characterized as increasing to a maximum at 
some intermediate n value, and remaining at or near that 
maximum with further increases. (Note that for P-1313 the 
function for attacks per interval with attack increased with 
each increase in n, up to 16 - the last value examined with 
this bird) . 

With subject P-7848, increasing n from 1 to 8 more than 
doubled mean attacks per interval with attack and increased 
the mean proportion of intervals with attack from 0.77 to 
0.98. When n was changed from 8 to 16, mean attacks per 



36 
interval with attack again increased, from 132.5 to 176.2, 
while the proportion of intervals with attack remained near 
the maximum value. Both measures of attack were essentially 
unchanged when n was increased to 24. Reexposure to various 
n values produced the same general function, although both 
measures were generally lower than those observed during the 
initial exposures. This may have resulted from the 
intervening exposure to larger food amounts or from a 
general decrease in attack levels across sessions. Such a 
decrease has been previously reported with induced attack 
(Cherek & Pickens, 1970) . It is likely, however, that the 
former variable is responsible because no general decline in 
attack was seen across sessions within any phase of the 
experiment. 

Both functions for P-5626 resembled those seen with P- 
7848, except that attacks per interval with attack reached a 
maximum at n = 8 (see Figure 6) . Further increases in n 
produced comparable levels of attacks per interval and the 
same maximum proportion levels. The means of these measures 
during the second (and third, for n = 1) exposure to various 
n values were comparable, but slightly lower, to those 
observed during initial exposures. 

The data from the phases at lower n values under 
conditions in which sessions were conducted every other day 
(P-5626 and P-7848) and when sessions ended after 10 
intervals (P-5626) suggest that the increases in attack were 



37 
indeed a function of increases in n, rather than a function 
of some characteristic of the different conditions required 
at larger n values. For example, it cannot be argued that 
the higher levels of attack observed at large n values were 
due simply to deprivation of the opportunity to attack that 
resulted from conducting sessions every other day. 

Although P-1313 had to be removed from the experiment 
before being exposed to all conditions, the data for this 
bird warrant examination. After attacking at relatively low 
levels during the early sessions of the n = 1 condition, 
this bird ceased attacking, and failed to do so for the 
final 22 sessions under this phase. When n was increased to 
eight, attacking occurred in the first session, and 
persisted for the remainder of this phase. The mean levels 
of attacks per interval with attack and proportion of 
intervals with attack for the last 15 sessions were 43.6 and 
0.97, respectively. When n was increased to 16, mean 
attacks per interval with attack increased to 84.7 and the 
proportion measure increased to 0.99 (see Figure 7). After 
92 sessions under this condition, both keypecking and 
attacking began to decrease until this subject failed to 
engage in either activity. Probe sessions at other n values 
failed to produce keypecking or attacking. This bird was 
removed from the experiment and perished shortly thereafter. 
The results presented in Figure 7 include only those 



38 
sessions prior to the sudden decrease and subsequent 
cessation of keypecking and attacking. 

The development of attack in P-1313 as a result of 
changing n from one to eight is shown in Figure 8. This 
figure shows daily levels of attack per interval with attack 
for the last 15 sessions of the n = 1 condition and the 
first 15 sessions of the n = 8 condition. This figure 
reveals that the zero levels of attack observed when n 
equaled one were substantially increased by the first 
session when n was increased to eight. Attack continued to 
occur at similar levels throughout this phase. 

Note that for all birds, when conditions arranged for 
intervals terminating in multiple grain cycle presenta- 
tions — when n was greater than one — attack occurred in 
nearly every interval (i.e., proportion values were usually 
near 1.0). In contrast, when n was one, attack occurred in 
fewer intervals per session. Thus, one major effect of 
programming multiple grain cycle presentations was to 
increase the likelihood of initiating attack, as well as to 
increase the amount of attack per interval once it was 
initiated. 

A summary of keypecking data for each bird for all 
conditions is provided in Table 2. For both P-562 6 and P- 
7848, response rates generally decreased and pause times 
generally increased as a function of n. For P-1313, no 



39 
systematic trend can be seen over the range of parameter 
values studied. 

Decreases in operant response rates and increases in 
pauses similar to those seen with P-7848 and P-5626 have 
been reported on FI schedules as a function of feeder cycle 
duration (Staddon, 1970) , or milk concentration (Lowe, 
Davey, & Harzem, 1974) . These results have been attributed 
to the "inhibitory" effects of food presentation (Lowe et 
al., 1974). Other studies, however, have reported a 
positive relation between operant response rates and 
reinforcement magnitude, and are generally attributed to the 
"motivational" or "strengthening" effects of food 
reinforcement (see Bonem & Grossman, 1988, for a review). 
The effects of reinforcement magnitude are quite 
inconsistent across studies and appear to depend upon a 
number of procedural characteristics. A more detailed 
discussion of the effects of this variable on operant 
behavior and the relevance to the present experiments will 
appear in the General Discussion. 

In summary, Experiment 1 revealed two major effects of 
increasing the amount of food per interval on schedule- 
induced attack: a) the amount of attack (as measured by 
attacks per interval with attack) is a direct function of 
the amount of food per interval, with this measure 
increasing to a maximum at some n value and remaining at 
high levels with further increases in n, and b) the 



40 
probability of initiating attack is higher when conditions 
arrange for the delivery of multiple grain cycles rather 
than a single cycle. These data extend those reporting that 
the larger of two amounts of food induced more attack on FT 
schedules (Flory, et al., 1988) by providing a 
characterization of the function over a greater range of 
parameter values. 



Figure 1. Diagram of experimental apparatus used to 
secure the target pigeon and measure attacks. This 
diagram is copied from Azrin, Hutchinson, & Hake 
(1966) . 



42 




Figure 2. Sample cumulative records from portions of 
sessions from n = 1, n = 8, and n = 16 conditions for 
P-7848 during Experiment 1. In the upper record of each 
condition, each keypeck stepped the response pen, the 
response pen deflected with each food presentation and 
reset after the last food presentation of an interval, 
and each attack deflected the event pen. In the lower 
record of each condition, each attack stepped the 
response pen, the response pen reset after the last 
food presentation of an interval, and each food 
presentation deflected the event pen. Records are 
taken from sessions in which the attacks per interval 
with attack measure closely approximated the mean for 
the last 15 sessions. 



44 



0- 
(/l 
UJ 

o 

o 




r^f^^ 





Figure 3. Sample cumulative records from entire 
sessions n = 1 and n = 16 conditions for P-5626 during 
Experiment 1. All conventions are as in Figure 2. 



46 



P-5626 




if) 

LU 

o 
o 
in 



wi"» « — ' — ' 1 — 1 1 — imamri m — t tt t-i « r f—im — 

r- ir- ii 1 ^Vn 



n=16 



imti iim iiitmi mt « wn — t — i — it » — f — f »— n» — ar — w — w— fn — it—m — ti ' 




^^^-^'^ — r->-n — tT^ 



-30 MIN- 



Figure 4. Sample cumulative records from n = 1, n = 8, 
and n = 16 conditions for P-1313 during Experiment 1. 
All conventions are as in Figure 2. 



CL 

Ld 

cr 

o 
o 



n=l 



n = 8 



n=16 



48 



P-1313 





-I — m 1 » — f- 



-» ff r- 



-T» r- 



■^-^"v— n — /-n^ r~T~vnr~ 



i^ r 



7'^_7j_jL^LjLy|jU_^jt_.^jL 



* — »»- 



-I W » wi 1 » » ; 1 1 r- 



^n 



A V 



50 MIN 



Figure 5. Attacks per interval with attack and the 
proportion of intervals with attack as a function of 
the amount of food per interval (n) for P-7848 from 
Experiment 1. Closed circles are from the initial 
exposure to each n value, open circles are from the 
second exposure to n = 1 and n = 16 conditions, and 
open triangles are from the third exposure to the n = 
condition. See text for specific characteristics of 
each condition. Values are means taken from the last 
15 sessions. Vertical bars indicate ranges. 



P-7848 



50 



2^ 


240 


o 




<■ 




t 




< 


7nn 


X 




h- 




5 




^ 


160 


> 




tr 




UJ 




z 


120 


a: 




UJ 




Q. 




tn 


80 


^ 




o 




< 




S 


40 








Determination 

• •Ist 

O 2ncl 

A 3rd 




6 






1.000 



g 0.750 

—I 

t 0.500^ 



P 0.250 

cr 

o 

a. 

o 

a: 

'^ 0.000 




"T" 

8 



16 



24 



AMOUNT OF FOOD (n) 



Figure 6. Attacks per interval with attack and the 
proportion of intervals with attack as a function of 
the amount of food per interval (n) for P-5626 from 
Experiment 1. All conventions are as in Figure 5. 



P-5626 



52 



O 



a: 



UJ 
Q. 

CO 
O 



lOOn 
80 
60 
40 
20 




Determination 

• •Ist 

O 2nd 

A 3rd 




6 



o 

i 



CO 

i 

UJ 



o 



Q:: 
o 

Q. 
O 
OH 



I.OOOi 



0.750 



0.500- 



0.250 



0.000 




■fr 



')■ 



4 8 16 

AMOUNT OF FOOD (n) 



24 



Figure 7 . Attacks per interval with attack and the 
proportion of intervals with attack as a function of 
the amount of food per interval (n) for P-1313 during 
Experiment 1. All conventions are as in Figure 5. 



P-1313 



54 



o 

i 

X 



UJ 



lij 

o 
< 



160- 



120 




I 



1.000 



t 0.750 






0.500- 



g 0.250 

a: 

o 

Q. 
O 

OH 

°- 0.000 




AMOUNT OF FOOD (n) 





c 




0) 


o 




X! 


•H 




■P +J 






•r^ 




U T) 







C 




<M 


o 






n 






H 


00 




CO 






1 


II 




1 


CI 




u 


(U 




Si 




M-l 4-) 




y. <w 












(C 






+j 


w 




-p 


c 




(0 


o 

•H 




£1 


in 




-p 


U] 




-H 


0) 




s 


m 




rH 


IT) 




(d 


H 




^ 


+J 




0) 


W 




4J 


u 




c 


■H 




-H 


tH 




}-l 


Q) 




<u x: 




a-p 




w -a 




>i 


C 




o 


(0 




(0 






+j 


H 




■p 






(0 


II 




(W 


CI 







0) 




w x: 




+j +J 




o 






rH 


(W 




a 


• 






rH 


>, w 




rH 


C 4J 


-H 





c 


(0 


•r^ 


0) 


Q 


W 


e 




(0 ' 


•H 




0) 


M 


• 


01 


Q) 


CO 




a 




in 


X 


0) 


rH 


u 


^ 






d -p 


e 


iji w 





•H 


(0 


^1 


C>H rH <H 



LO 



56 



00 

II 

c 



o 



- in 



T 

Q_ 



[\ 



C/) 

o 

UJ 
(jO 



CM 



o 



ooooooooooo 

OOOCD'vfCslOOOCD^CM 
CN ^ ^ ^ ^ ^ 



>iOVllV HUM 1VAd3lNI d3d S>i3VllV 



57 



TABLE 1 

The order of conditions and number of sessions in each for 
all subjects in Experiment 1. Each subject responded on a 
Ch FI t FR 1 X n schedule of food presentation. Sessions 
ended after 15 intervals and run 5 days per week unless 
otherwise noted. 

n value sessions 

P-7848 



120 
61 
32 
27 
32 
52 
34 



138 
83 
78 
44 

120 
47 
51 



t = 4 min 

1 117 

8 58 

16^ 98 

Sessions conducted every other day 
Sessions ended after 10 intervals 



t = 12 min 






1 




8 




16^ 




24^ 




1 

8^ 

1^ 


P-5626 




t = 4 min 






1 




8 




16^ 

24^'^ 




1 




16^ 
l1,2 


P-1313 





58 



TABLE 2 

Overall keypeck rates and average pause times during the FI 
for each subject for every condition of Experiment 1. 
Values are means for the last 15 sessions. Values in 
parentheses are ranges. Each subject responded on a Ch FI t 
FR 1 X n schedule. 



n keypecks/min pause/interval (min) 



p- 


■7848 










t 


= 12min 












1 


24.5 


(20.1-29.9) 


2.9 


(1.7-4.0) 




8 


24.0 


(20.5-33.5) 


3.2 


(1.7-4.3) 




16 


18.0 


(15.3-25.1) 


4.3 


(3.2-5.5) 




24 


14.2 


(11.3-17.2) 


4.5 


(3.5-6.1) 




8 


30.8 


(25.0-41.7) 


2.9 


(1.6-4.0) 




1 


27.8 


(24.2-30.5) 


3.0 


(1.6-5.2) 


p- 


■5626 










t 


= 4min 












1 


27.4 


(21.7-30.8) 


1.5 


(1.3-2.1) 




8 


25.6 


(17.5-45.0) 


1.7 


(1.3-2.4) 




16 


20.8 


(18.3-32.8) 


2.0 


(1.1-2.5) 




24 


17.4 


(10.6-23.9) 


2.2 


(2.0-3.0) 




1 


27.7 


(23.1-37.8) 


1.5 


(0.9-1.9) 




16 


19.7 


(6.5-24.5) 


2.1 


(1.6-2.6) 




1 


30.1 


(21.9-33.3) 


1.5 


(1.2-2.1) 




4 


29.0 


(22.4-37.8) 


1.8 


(1.4-2.3) 


p- 


-1313 










t 


= 4min 












1 


32.6 


(0.5-56.9) 


2.3 


(1.1-8.7) 




8 


37.3 


(23.8-46.5) 


2.1 


(1.5-2.7) 




16 


25.2 


(9.9-40.8) 


1.9 


(0.9-2.6) 



EXPERIMENT 2 



Introduction 



The results from Experiment 1 indicated that induced 
attack was a monotonic, increasing function of the amount of 
food presented dependent upon keypecking. Data from studies 
of induced polydipsia with rats, however, suggest that 
relations obtained from manipulations of amount of food 
across sessions may change when comparisons of different 
food amounts are made within sessions. When presented food 
pellets according to an FT schedule, rats drank slightly 
more when multiple pellets (four or six) were delivered than 
when one pellet was delivered each interval per session 
(Reid & Dale, 1983; Reid & Staddon, 1982). However, when 
intervals ending in multiple pellets were interspersed with 
intervals ending in one pellet within experimental sessions, 
rats drank more in those intervals that followed one pellet 
and during those intervals that ended in one pellet, if 
those intervals were signalled (Reid & Dale, 1983; Reid & 
Staddon, 1982) . While the determinants of the differences 
in across- and within-session comparisons are not clear, 
these data suggest that the function relating induced 



59 



60 

polydipsia to amount of food may depend critically upon the 
context in which the amount of food is manipulated. 
Experiment 2 was conducted to determine if the 
relationship revealed in Experiment 1, when the amount of 
food was varied across experimental phases, would hold when 
varied within sessions. If a comparable relation is 
obtained, then the generality of the results of the first 
experiment would be demonstrated. However, if differences 
similar to those discussed above with polydipsia are seen, 
further analysis would be required to determine the factors 
responsible. 

Method 
Subjects 

P-5626 and P-7848 served as experimental subjects. 
Each was maintained at 80% of its free-feeding body weight. 
Each subject was paired with a target pigeon. For P-562 6, 
the target was the same as in Experiment 1; for P-7848, the 
target was different than in Experiment 1. The target for 
P-562 6 became ill midway through this experiment and was 
replaced. Each target was given free access to food and all 
birds were individually housed with water and health grit 
continuously available. 



61 

Apparatus 

The apparatus used in this experiment was the same as 
in Experiment 1. 
Procedure 

After completion of the sequence of conditions listed 
in Table 1, P-5626 and P-7848 were exposed to a two- 
component multiple schedule in which n = 1 and n = 16 
conditions alternated irregularly within experimental 
sessions. For P-5626 the schedule was a Mult [Ch FT 4 FR 1 
X 1] [Ch FI 4 FR 1 X 16] ; the schedule for P-7848 was a Mult 
[Ch FI 12 FR 1 X 1] [Ch FI 12 FR 1 x 16]. The component 
that began the session was determined randomly. Components 
alternated irregularly and lasted either 2, 3, or 4 
intervals. For P-5626, a clicking sound accompanied the n = 
16 component. For P-7848 the clicker accompanied the n = 1 
component. Sessions were terminated after 9 intervals had 
occurred in each component. Components were separated by 
30-s time-outs (TOs) during which the chamber was dark, no 
experimental events were programmed, and attacks were 
recorded (but had no effect on TO duration) . Changeover 
contingencies in Experiment 2 were identical to those in 
Experiment 1. 

After 51 sessions for P-5626 and 47 sessions for P- 
7848, the TOs were lengthened to 60-s. This condition 
lasted 33 sessions for P-5626 and 30 sessions for P-7848. 



62 
The target for P-5626 was replaced on the ninth session of 
this condition. 



Results and Discussion 

Figures 9 and 10 show representative cumulative records 
of responding under the multiple schedule for P-562 6 and P- 
7848, respectively. Several general characteristics of 
responding are illustrated in these records. First, keypeck 
patterns for both birds resembled those seen in Experiment 
1. Second, attacks usually occurred during the periods 
immediately after the last grain presentation of an 
interval. (Note that P-7848 often continued to attack well 
into the interval) . Third, more attack was induced in the n 
= 16 component. 

The third characteristic listed above is quantitatively 
summarized in Figures 11 and 12. Figure 11 presents attacks 
per interval with attack and proportion of intervals with 
attack in each component for P-5626; Figure 12 shows these 
data for P-7848. For P-5626, both measures of attack were 
higher during the n = 16 component, but the differences in 
attack were not as great as seen in Experiment 1. In 
Experiment 1, this bird attacked in virtually every interval 
when n was 16, while during the multiple schedule, attack 
usually occurred in all but one interval. This interval was 



63 

usually the first interval after a component change or the 
first interval of the session. 

The data for P-7848 were similar to those for P-5626 in 
that, although more attack was observed under the n = 16 
condition than when n was 1, the differences were not as 
great as in Experiment 1. This was primarily the result of 
elevated levels of attack (in both measures) under the n = 1 
condition. Attacks per interval under the n = 16 condition 
were similar in both Experiments. As with P-5626, this bird 
did not attack in every interval when n was 16, and 
intervals that lacked attack in this component were usually 
the first interval following a component change or the first 
interval of the session. 

Keypecking data from Experiment 2 are shown in Table 3 . 
As in Experiment 1, rates were lower and pause times were 
longer when n was 16. 

One advantage of employing a multiple schedule for the 
present comparison is that, because both experimental 
conditions (n = 1 and n = 16) occur within the same session, 
attacks during both conditions are similarly exposed to 
effects of extraneous, uncontrolled variables. Although not 
necessarily the case, it is quite possible that those 
variables do not operate differentially on attack in the two 
components of the multiple schedule. If this is indeed the 
case, then it might be illustrative to compare the number of 
sessions in which attack was higher under the n = 1 and n = 



64 
16 conditions. For both birds, attacks per interval with 
attack were higher during the n = 16 component in each of 
the last 15 sessions. For the proportion measure, attack 
was higher during the n = 16 component in 6 of these 
sessions for P-5626 and in 5 of these sessions for P-7848. 
This measure was never higher during the n = 1 component for 
P-5626 and was higher in only 1 session for P-7848. 

Employing a multiple schedule to compare conditions 
within experimental sessions is not without its 
disadvantages. Interactions between components is 
frequently observed in studies using multiple schedules 
(e.g. Bloomfield, 1966; Pear & Wilkie, 1971; Reynolds, 
1961) . It is possible that such interactions occurred in 
the present experiment. Inspection of the cumulative 
records in Figures 9 and 10 reveals that for both birds 
elevated levels of attack were sometimes seen in the first 
interval of n = 1 components and reduced levels were 
sometimes seen in the first interval of n = 16 components. 
It is quite possible that attacking in the first interval of 
a component is at least partially controlled by the amount 
of food delivered in the final interval of the preceding 
component rather than by the stimulus correlated with the 
current component, despite the 30-s TO's between components. 
When the TO durations were increased to 60-s, no change in 
this characteristic of attack, or in overall levels of 
attack was observed. The smaller differences in levels of 



65 
attack between n = 1 and n = 16 conditions in Experiment 2 
(compared with those seen in Experiment 1) , also may have 
resulted from interaction between the two components. 
Perhaps attacking was partially controlled by some overall 
session average of food amount, and this source of control 
attenuated the differences seen in Experiment 1. Despite 
these limitations, the data presented in Figures 9, 10, 11, 
and 12 and the proportion of sessions in which attack during 
the n = 16 component was greater provide substantial 
evidence that attack is more likely when larger amounts of 
food are delivered, even when large and small amounts 
alternate within experimental sessions. 



fS 


0) 




^-1 


+J 


3 


C T3 


0) 


Q) 


e 


U 


•H 





>^ 


^ 


0) 


a 


a 




X "w 


w 


o 


g 


Ul 


rH 


V^ 


•rH 


<)-l 


(C 




+J 


VO 


0) 


(N 


T! 


VO 




in 


^H 


1 





CU M-l 


U +J 





X 


4-1 


0) 




+J 


Tl 




U 


Q) 





0) 





W 


0) 




^ 




0) 


CM 


> 




•H 


0) 


+J 


Vh 


(C 


3 


r-{ 


tri 


3 


-H 


e fe 


3 




o 


c 




-H 


<u 




tH 


w 


a (0 


e 




(C 


Q) 


Cfl 


Vh 




(0 


< 






Ul 




c 


• 


o 


CTi 


•H 




-p 


Q) 


c 


^ 


0) 


3 


> 


CP C 


•H 





Ci^ 






CD 
CD 

tn 
I 

CL 




e 



67 



O 





■SdS3d 00? 



rg 


• 




(1) 


■P 


M 


C 


d 


0) TJ 


G 


0) 


•H 





u 





0) 


V4 


a a 


X 




W iw 




o 


e 




o 


(Q 


U H 


<W 


•H 




(C 


CO -P 


■>* 


Q) 


CO -O 


r^ 




1 


^ 


cu 


O 




(w 


u 







-P 


<4-l 


X 




(1) 


T3 -P 


^ 




O 


0) 


O 


Q) 


0) 


W 


i^ 




Q) 


• 


> 


CM 


•H 




+J 


<D 


(0 


U 


rH 


3 


d 


0^ 


e 


-H 


3 &^ 









c 


Q) 


•H 


H 




a w 


s 


(0 


(0 




u 


0) 




M 


< 


(0 




w 


• 


c 


o 





H 


-H 




-p 


Q) 


c 


U 


0) 


3 


> 


D> C 


•H 





U-, 


o 




69 







o 



' ScSB^ 005 ' 



Figure 11. Mean levels of attacks per interval with 
attack and proportion of intervals with attack for P- 
562 6 for n = 1 and n = 16 components during Experiment 
2. Striped bars are from the n = 16 components. 
Values are from the last 15 sessions. Vertical bars 
indicate ranges. 



P-5626 



71 



< 



80 



60- 



a: 



40- 



bJ 
D_ 

CO 
< 



20 







I 



a: 



a: 
o 
a. 
o 
on 

D. 



1.000 



t 0.750- 



0.500 



R 0.250 



0.000 




1 16 

AMOUNT OF FOOD (n) 



Figure 12. Mean levels of attacks per interval with 
attack and proportion of intervals with attack for P- 
7848 for n = 1 and n = 16 components during Experiment 
2. All conventions are as in Figure 11. 



P-7848 



73 



< 



< 
> 

a: 

LlJ 



a: 

UJ 
CL 

en 
< 



200 
160 
120 
80' 
40- 
0- 



I 



V) 



> 

DC 

LlI 



u. 
o 



o 

Q. 
O 

a: 

D. 



I.OOOi 



t 0.750 



0.500 



i 0.250- 



0.000 




1 16 

AMOUNT OF FOOD (n) 



74 



TABLE 3 

Overall keypeck rates and average pause times for both 
subjects during the FI in each component of the mult [ch FI 
t FR 1 X 1] [ch FI t FR 1 X 16] schedule of food presentation 
used in Experiment 2. Data are from conditions when the time- 
out duration was 3 s. Values shown are means for the last 
15 sessions. Ranges are indicated in parentheses. 



P-5626 n 
t = 4 min 

1 
16 



P-7848 

t = 12 min 

1 
16 



kevpecks/min 


pause fmin) 

1 


22.0 (19.4-26.1) 


1.1 (0.7-1.6) 


14.7 (10.0-22.2) 


1.9 (1.4-2.7) 

1 

1 


24.7 (17.2-33.6) 


1 
1.7 (1.0-2.6) i 


18.0 (9.5-24.8) 


3.2 (1.9-5.0) : 



GENERAL DISCUSSION 

In both experiments, induced attack by pigeons was 
positively related to the amount of food delivered on an FI 
schedule. In Experiment 1, when the amount of food per 
interval was examined across phases, attacking increased to 
a maximum and remained at high levels with further increases 
in food amount. In Experiment 2, when two different amounts 
alternated within the context of a multiple schedule, attack 
was higher in the component that programmed more food, with 
the differences slightly less than those observed in 
Experiment 1. 

Considerations of the results of the present study can 
conveniently be made within the context of the theoretical 
frameworks presented in the General Introduction. The 
frameworks discussed were the classification of induced 
attack as a member of a class of "adjunctive behaviors" 
(Falk, 1969, 1971), the view of induced attack as arising 
from aversive properties of intermittent schedules of food 
presentation (Azrin, 1961; Azrin et al., 1966; Hutchinson et 
al., 1968), an analysis of induced attack as a form of 
"interim activities" (Staddon, 1977; Staddon & Simmelhag, 
1971) , and the view that induced attack results from 

75 



76 

"arousal" generated by presentation of food (Killeen, 1975; 
Killeen et al., 1978). In addition, two other 
interpretations of the present results will be considered, 
one in terms of principles of reflexive behavior, and 
another in terms of "an opponent-process theory of 
motivation" (Solomon & Corbit, 1974) . 

The results of the present experiments are, for the 
most part, incompatible with Falk's view. Although attack 
observed in these studies shares a number of characteristics 
with other induced activities classified as adjunctive 
(e.g., attack was induced by intermittent food presentation, 
and occurred in the post-reinforcement period) , a 
monotonically increasing function relating attack to amount 
of food is not predicted from Falk's "consummatory rate 
hypothesis." Recall that in Falk's view, adjunctive 
activities are bitonically related to the rate of food 
presentation, with high levels induced at intermediate food 
rates, and low levels induced both at high and at low food 
rates (Falk, 1969, 1971). Thus, according to this view, 
levels of attack in Experiment 1 should have decreased 
substantially at the larger food amounts (n = 16 and n = 
24) . While it might be argued that such a decrease would 
have occurred had larger amounts of food been examined, 
previous experiments on induced drinking and induced attack 
have shown that, when fixed food amounts were intermittently 
presented (e.g., one food pellet or one grain cycle), levels 



77 

of these behaviors began to decline as food rates were 
increased to greater than one unit per 2.5 min (0.4 units 
per min) (Falk, 1966) . Other data indicate that induced 
behaviors begin to decline as food rates are increased to 
greater than one unit per minute (e.g., DeWeese et al., 
1972; Falk, 1966; Flory, 1969). These results suggest that 
the highest food rates in Experiment 1 were sufficient to 
produce a decrease predicted by Falk's hypothesis. During 
the present experiment, attack levels continued at maximum 
levels at food rates of six units per minute (P-5626 at n = 
24) and of two units per minute (P-7848 at n = 24) . Also, 
as mentioned earlier, other studies examining induced attack 
(Flory et al., 1988) and induced drinking (Bond, 1973) under 
different combinations of food amounts and interfood 
intervals have reported data at odds with the consummatory 
rate hypothesis. Those results, as well as those reported 
here, suggest that it may be useful to consider 
manipulations of food amount and interfood interval as 
separate variables. 

The data from the present study at first seem 
incompatible with the view that induced attack is produced 
by aversive properties of intermittent schedules of food 
presentation. If aversive aspects of conditions arranged in 
the present experiments were responsible for the production 
of attack, it seems likely that smaller amounts of food 
would have resulted in more attack. In the sense that 



78 

conditions arranging for lower frequencies or amounts of 
reinforcement are less preferred (see de Villiers, 1977) , 
they could be considered as relatively more aversive, and 
might be expected to induce higher levels of attack. Such 
is certainly the case when the extremes are programmed, as 
when periods of FR 1 alternate with periods of extinction 
(Azrin et al., 1966). 

An interpretation of the present results in terms of 
schedule aversiveness is^ still possible, however, by 
considering FI schedules as suggested by Schneider (1968) . 
In this view, FI schedules are similar to programming 
alternating periods of extinction and periods in which a VI 
schedule is in effect (with the value of a given interval 
determined by the post-reinforcement pause) . Thus, the 
period just after food presentation functions as an S\ and 
the period towards the end of the interval functions as an 
S° . Indeed, with respect to induced behavior, it has been 
suggested that the periods of zero reinforcement probability 
just after food presentation on intermittent schedules 
function similarly to programmed periods of extinction 
(e.g., Azrin, 1961; Hutchinson et al, 1968; Richards & 



^The term aversiveness is used here only as a reference to 
certain effects upon behavior. A set of conditions is 
called aversive only to the extent that these conditions are 
escaped and avoided, or to the extent that aggressive 
behavior is produced. Use of the term is not meant to imply 
that the property of aversiveness exists independent of any 
measurable dimension of behavior, and is measured, if at 
all, in some separate dimension. 



79 
Rilling, 1972) . In viewing FI schedules of food 
presentation in this fashion, the increase in attack as a 
function of increasing the amount of food may have resulted 
from an increase in the relative aversiveness of post-food 
stimuli. Such an effect might be expected on the basis of 
data showing negative behavioral contrast in multiple 
schedules. That is, when the rate of food presentation is 
increased in one component of a multiple schedule, the rate 
of responding in the other (unchanged) component often 
decreases (e.g., Reynolds, 1961). Thus, the "strength" of 
operant behavior maintained in a given set of stimulus 
conditions is dependent upon context. It is possible that 
the aversive characteristics of S^ periods are also 
dependent upon context. Indeed, the aversiveness of the 
post-reinforcement period during ratio schedules (as 
indicated by the likelihood of escape) is dependent upon the 
size of the ratio (e.g., Appel, 1963; Azrin, 1961; Thompson, 
1964). Thus, the aversiveness of the early portions of the 
FI in the present experiment may have increased as a result 
of increases in the amount of food presented in the terminal 
component, resulting more attack and less keypecking. Such 
an interpretation is supported by data demonstrating higher 
levels of attack during extinction components of a multiple 
schedule as a function of the number of food reinforcements 
delivered according to an FR 1 schedule in the other 
component (Azrin et al., 1966). 



80 
An important test of the behavioral contrast view 
presented above might be to compare the effects of 
reinforcement amount on schedule-induced escape. This view 
predicts that larger amounts of reinforcement would induce 
more escape. Also, it might be informative to evaluate the 
effects of a type of "errorless" discrimination training 
(Terrace, 1963,1964). In errorless discrimination training, 
S'' is gradually introduced so that its behavioral function 
is acquired with very few "errors" (i.e., responses during 
S*) . Terrace (1963, 1964) reported that the usual 
"emotional" responses (e.g., aggression) often observed 
during S" periods were lower in experimental subjects 
trained errorlessly. Terrace also reported that 
manipulations usually resulting in behavioral contrast 
failed to do so in subjects trained in this fashion. If 
the effects of the amount of food reinforcement on attack in 
the present experiments are an example of behavioral 
contrast, then subjects with a training history in which the 
FI schedule parameter was increased very gradually (i.e., a 
gradual introduction of S") might be expected to attack less 
than subjects for which the FI schedule parameter was 
abruptly increased. 

The relationship of the present data to the theoretical 
position offered by Staddon and his colleagues (Staddon, 
1977; Staddon & Ayers, 1975; Staddon & Simmelhag, 1971) is 
not straightforward. Recall that, in this framework. 



81 

because motivational variables governing interim responses 
depend upon those governing terminal responses, operations 
that increase the reinforcing efficacy of the terminal event 
should produce increases in levels of both interim and 
terminal activities. Indeed, the principal findings of the 
present studies provide support for Staddon's 
conceptualization. The monotonic increasing function 
relating induced attack to food amount is consistent with 
predictions based upon this view. However, rather than 
increasing as predicted, terminal responding (keypecking) 
decreased as a function of food amount. Thus, while it 
seems that this view is useful with respect to predictions 
of the effects of food amount on schedule-induced attack, 
keypeck data from the present studies make it difficult to 
assess the utility of this view as a general conception of 
behavior. 

Recent studies seem to have occasioned a slight 
restructuring of Staddon's view (Reid & Dale, 1983; Reid & 
Staddon, 1982) . In these studies, induced drinking (an 
interim activity) and "head-in-feeder" (a terminal activity) 
in rats were examined during FT 60-s schedules of food 
presentation. In the experiment by Reid & Staddon (1982) , 
occasional inteirvals ending in six pellets were interspersed 
with intervals that usually ended in one pellet. In the 
Reid & Dale (1983) study, intervals ending in four pellets 
randomly alternated with intervals ending in one pellet. In 



82 
both of these experiments, levels of interim drinking were 
lower and levels of terminal responding were higher during 
intervals that followed presentation of the larger food 
amount. When different stimuli were present during 
intervals ending in different food amounts, levels of 
drinking were lower and levels of terminal responding were 
higher in intervals beginning and ending in the larger food 
amount. These results led the investigators to suggest that 
terminal activities are both elicited by food and occur in 
"anticipation" of food, and that terminal activities and 
interim activities are "reciprocally, linearly related" 
(Reid & Dale, 1983) . In this view, then, interim activities 
are only indirectly controlled by food presentation, and the 
amount of interim responding observed under intermittent 
schedules is primarily determined by the amount of terminal 
responding generated by that schedule. The results of the 
present experiments suggest that induced attack and operant 
behavior are reciprocally related: as attack increased, 
keypecking decreased. However, the functions relating each 
of these responses to food amount are directly opposite of 
those predicted on the basis of data reported by Reid & Dale 
(1983) and Reid & Staddon (1982). 

The data from studies by Reid & Dale (1983) and Reid & 
Staddon (1982) discussed above were obtained when 
manipulations of food amount made within experimental 
sessions. However, as noted in the Introduction to 



83 

Experiment 2, the effects of food amount in those studies 
were entirely different from comparisons that were made 
across sessions (Reid & Staddon, 1982) , or across phases 
(Reid & Dale, 1983) . In those cases, the larger of two food 
amounts induced more drinking, but had no systematic effect 
on terminal responding. In contrast, in the present 
studies, induced attack was positively related and 
keypecking was inversely related to food amount, both when 
comparisons were made within sessions and across phases. 
The reasons for the disparity in these findings are not 
clear. Perhaps some of the differences in results were due 
to differences in species used, responses measured, inducing 
schedules, apparatus used, or measures of induced 
responding. In the studies by Reid & Staddon (1982) and 
Reid & Dale (1983) , the mean percent of 1-s bins containing 
drinking and head-in-feeder were measured as a function of 
time in the interfood interval. This measure provided an 
estimate of the probability of these two activities at 
various points within the interfood interval. It is 
possible that such partial-interval recording resulted in 
different estimates of responding than if more conventional 
measures had been used (e.g, rate, response per interval, 
total amount) . This seems unlikely, however, given that the 
correspondence between interval recording methods and 
continuous measures (such as response rate) is greatest when 
short intervals are used (Powell, Martindale, & Kulp, 1975), 



84 
and that rather short intervals were used in those 
experiments (1-s) . Thus, it seems as though the differences 
in data obtained in those experiments and in the experiments 
presented here result from features other than measurement 
procedures . 

The present results also relate to the theoretical 
framework proposed by Killeen (1975) and Killeen et al., 
(1978) . This conceptualization suggests that a variety of 
induced behaviors result from "arousal" generated by food 
presentation. Repeated presentation of food produces an 
accumulation of arousal such that the excessive character of 
induced behavior is observed. This model predicts that 
larger amounts of reinforcement ("incentive") should produce 
more arousal, and thus, more induced behavior (Killeen et 
al, 1978) . The direct relation between induced attack and 
amount of food presented here are in accord with this view. 
Killeen et al., (1978), however, go on to suggest that as 
food amount is increased, it is possible that arousal will 
be diminished through satiation. Thus, at very large food 
amounts, induced attack, for example, might be expected to 
decrease. Such a decrease was not seen in the present 
results. Satiation, however, did not appear to be a factor 
in the present experiment. Inspection of the cumulative 
records presented in Figures 2, 3, and 4 reveals little 
evidence of a decline in keypecking as session progressed 
for any subject during any phase of Experiment 1. 



85 

While the increase in attack as a function of food 
amount is predicted by Killeen's model, other features of 
the present results differ from predictions based upon this 
model. For example, Killeen et al . , (1978) reported peak 
rates of activity at about one-quarter into the interfood 
interval, regardless of interval duration. In the present 
study, highest attack rates were observed during the period 
immediately following food presentation. Indeed, inspection 
of cumulative record figures reveal that, for the most part, 
attacking occurred at rather constant rates in the early 
portion of the interval (rather than positively accelerated 
rates, as predicted by Killeen) . Note, that there were 
occasional exceptions to both of these general 
characteristics (see Figures 3 and 10) . However, these were 
not consistent across conditions or across birds. Thus, the 
differences in temporal characteristics between attack seen 
here and activity measured by Killeen et al. (1978), suggest 
that these behaviors may result from different processes. 

A alternative interpretation of the present results is 
derived from relations obtained from studies of reflexes. 
Although attack occurs closely following food presentation, 
as might be expected if it was elicited, some investigators 
reject the possibility that attack and other induced 
activities are respondent in nature (e.g., Falk, 1971). 
Certain characteristics are often cited that seem to 
preclude classification of induced activities as 



86 

unconditional respondents elicited by food or by eating. 
For example, induced behaviors usually take several sessions 
to develop (e.g., Falk, 1971; Magyar & Malagodi, 1981), they 
can be modified by consequences (Bond, Blackman, & Scruton, 
1973; Dunham, 1971), and certain operations will produce a 
shift in their temporal locus within the interfood interval 
(Gilbert, 1974) . However, it has been argued that the 
tendency to reject interpretations of induced behavior as 
respondent is premature ( Wether ington, 1982) . Wetherington 
reviews data from studies on the effects of repeated 
elicitations, such as sensitization, habituation, temporal 
conditioning, temporal summation, and emergence of new 
unconditional responses. These data suggest that many 
respondents may actually possess characteristics that have 
been cited as evidence against a view that schedule-induced 
behavior is elicited. The results from the present 
experiments are in accord with predictions that are likely 
to emerge from a view of induced attack as an unconditional 
response to food presentation. Increases in attack as a 
function of increases in the amount of food can be 
considered an example of the Law of Intensity/Magnitude 
(Sherrington, 1906) . 

A final interpretation of the function relating attack 
to food amount can be made on the basis of an "opponent- 
process theory of motivation" (Solomon & Corbit, 1974) . 
These theorists argue that presentation of an emotion- 



87 
arousing stimulus (e.g., food or electric shock) produces 
two important effects. The initial effect is called the 
"primary affective reaction," or "a process," and is what 
is generally expected in the presence of that stimulus 
(e.g. , "happiness" if it is a positive reinforcer) . The a 
process is assumed to elicit, in turn, an "affective after- 
reaction," called the "opponent" or "b process," that 
generates an opposite emotional reaction (e.g., 
"unhappiness") . The overall emotional change that occurs 
when a stimulus is presented and then withdrawn is the net 
result of the primary and opponent processes. The a process 
ceases immediately when the stimulus is withdrawn, while the 
b process lingers unopposed after the stimulus is 
terminated. This model can be described as homeostatic in 
that it is assumed that physiological mechanisms underlie 
these processes and act to control emotional behavior by 
minimizing deviations from emotional neutrality. 

The following example may help to clarify the nature of 
the opponent processes. Solomon & Corbit (1974) describe 
behavior changes in a dog subjected to "intense" aversive 
stimulation (electric shock) . The dog was placed in a 
Pavlov harness and was given periodic 4-mA, 10-s electric 
shocks. The initial effect of shock presentation was 
described as "terror and panic," which included expulsive 
defecation and urination, pupil dilation, piloerection, and 
heart rate increase. After shock was terminated, this "a 



88 
state" gave way to a state of "stealth," during which the 
animal was subdued and relatively inactive, and during which 
heart rate decreased to levels below those observed prior to 
shock delivery. After a minute or so, this "b state" was 
replaced by normal behavior patterns and heart rate. After 
a number of repeated presentations of shock, the 
characteristics of the a state were diminished (e.g., 
behavior patterns were described as "annoyed and anxious," 
and heart rate increase was attenuated) , and b state 
characteristics were augmented (e.g., behavior patterns were 
described as "euphoric and active," and heart rate decreases 
were greater) compared to those seen during initial shock 
presentations. In this framework, the a process is 
unchanged, and the b process is strengthened, by repeated 
stimulus presentation. This presumably explains the changes 
observed in the dog's behavioral patterns and heart rate in 
the above example. Solomon & Corbit (1974) , interpret a 
number of behavior phenomena in terms of this theory, such 
as drug addition and certain characteristics of escape and 
avoidance. 

The opponent-process theory of motivation seems 
relevant to schedule-induced behavior, particularly induced 
attack. Schedule-induced attack generally occurs at high 
probability just after food presentation (i.e., during the 
period in which the effects of the b process are strongest) . 
In addition, according to Solomon & Corbit, (1974) , 



89 

activities generally observed during aversive conditions 
should occur during post-food periods. Attack is often 
observed under conditions in which aversive stimuli are 
presented (Azrin et al., 1965; Azrin et al., 1964: Ulrich & 
Azrin, 1962) • Also, several food presentations are often 
required before attack and other schedule-induced activities 
develop (Dove, Rashotte, & Katz, 1974; Magyar & Malagodi, 
1980) . This characteristic of induced behavior is predicted 
by the opponent-process theory, due to strengthening of the 
b process by repeated stimulus presentations. Finally, the 
opponent-process theory suggests that increases in the 
intensity of the stimulus (e.g., food amount) should result 
in an increase in both the a process and the b process. In 
example above in which a dog was presented periodic 10-s 
electric shock, when shock intensity was increased from 4-mA 
to 8-mA, a moderate increase in the magnitude of the heart 
rate elevation was observed during shock, and a dramatic 
increase in the magnitude of the heart rate decline was 
observed following termination of shock (Church, LoLordo, 
Overmier, Solomon, & Turner, 1966) . These data are 
compatible with the relation between food amount and attack 
observed in the present study: as the amount of food was 
increased, the magnitude of the b process is increased, 
resulting in more attack. 

Finally, the effects of food amount on keypecking in 
the present experiment must be considered. A number of 



90 

studies have indicated that the function relating operant 
responding to reinforcement magnitude is positive, 
especially when VI schedules are concurrently or multiply 
arranged (Catania, 1963; Fantino, Squires, Delbruck, & 
Peterson, 1972; Merigan, Miller, & Gollub, 1975). This 
relation has also been observed under simple FI schedules 
(Guttman, 1953) , and under FI second-order schedules of 
token reinforcement (Malagodi, Webbe, & Waddell, 1975) . The 
data reported here and elsewhere, however, seem to suggest 
that the relation between reinforcement magnitude and 
operant responding is negative. For example, when five 
different feeder cycle durations (Staddon, 1970) , and when 
four different milk concentrations (Lowe et al., 1974) were 
randomly presented on FI schedules, operant response rates 
decreased and pause times increased as a function of the 
preceding reinforcement magnitude. Indeed, there is 
considerable disagreement about the effects of reinforcement 
magnitude on operant behavior. The effects of this variable 
depend critically upon the procedures used, and upon the 
baseline schedules under which reinforcement is presented. 
For a review of the literature in this area, and a 
discussion of methodological and theoretical issues relevant 
to these studies, see Bonem & Grossman, (1988) . 

Presentation of reinforcing stimuli often have multiple 
behavioral effects. In addition to rate increasing, or 
strengthening effects, reinforcement can also have 



91 

discriminative properties (e.g., Ziininennan, 1971). Perhaps 
inconsistencies in the effects of reinforcement magnitude on 
operant behavior result, in part, from differences in the 
degree to which certain schedules establish reinforcement 
presentation as discriminative. For example, post- 
reinforcement pauses typical of behavior maintained by FR 
and FI schedules of have been interpreted as resulting from 
S' properties of reinforcement presentation, in that 
reinforcement never closely follows a previous reinforcement 
(e.g., Ferster & Skinner, 1957). It is quite possible that 
the increases in pause duration as a function of 
reinforcement magnitude observed in the present study, and 
in other studies (Lowe, et al . , 1974, Staddon, 1970), result 
from an increase the S* function of reinforcement delivery. 
The increase in attack observed in the present experiments 
is also consistent with this interpretation. Thus, under 
conditions in which reinforcement presentation is less 
likely to serve an S'' function (e.g., VR and VI schedules), 
increasing reinforcement magnitude might not produce an 
increase in pausing and induced attacking. 

It is also possible that the increase in pausing by P- 
7848 and P-5626 was an indirect function of the increase in 
attacking. That is, keypecking began later in the interfood 
interval under larger food amounts simply because attacking 
continued later into the interval. This did not appear to 
be the case as causal observation and inspection of the 



92 

cumulative records (Figures 2, 3, 9, and 10) indicated that, 
in most cases, post-reinforcement pauses were not entirely 
subsumed by attacking, even at large food amounts. Precise 
statements regarding the interaction of keypecking and 
attacking, however, require more extensive data analysis 
than possible here. 

In conclusion, the data presented in these experiments 
are important for a number of reasons. For example, while 
relevant to each of the theoretical positions discussed 
above, the relationship between attack and food amount 
observed here does not provide conclusive evidence for the 
selection of one position over the others. Indeed, in view 
of the literature on schedule-induced behavior as a whole, 
such a selection is extremely difficult. Each of these 
theoretical frameworks is supported by data from some 
studies but not others. It is contended here that a number 
of schedule and consequence variables have not been studied 
extensively enough to permit adequate theoretical 
integration (See General Introduction) . Thus, the results 
of the present experiments are important in that a 
functional relation between attack and food amount is 
demonstrated over a range of parameter values not previously 
reported, and the generality of that relation is extended by 
showing comparable effects during a multiple schedule. Only 
after further analyses of this sort, can questions 
pertaining to the utility of these, or other, theoretical 



93 
views be answered. In addition, the data presented here are 
relevant to issues regarding classification of various 
schedule-induced activities. It appears that induced attack 
and induced polydipsia are not always related to amount of 
food reinforcement in the same way. Although many of the 
theoretical positions presented above tend to classify 
induced activities together, the data from the present 
experiments suggest that these activities may result from 
different properties of intermittent reinforcement schedules 
and, thus, may be more profitably considered as functionally 
distinct. 



REFERENCES 



Allen, J. D. , & Kenshalo, D. R. (1976). Schedule-induced 
drinking as a function of interreinf orcement interval 
in the Rhesus monkey. Journal of the Experimental 
Analysis of Behavior . 26 . 257-267. 

Allen, R. F., Sicignano, A., Webbe, F. M. , & Malagodi, E. F. 
(1980). Induced attack during ratio schedules of 
reinforcement: Implications for measurement of 
adjunctive behaviors. In CM Bradshaw, E. Szabadi, & 
C. F. Lowe (Eds.), Quantification of steady-state 
operant behavior (pp. 385-388) . Elsevier/North-Holland 
Biomedical Press, Amsterdam, 

Appel, J. B. (1963). Aversive aspects of a schedule of 
positive reinforcement. Journal of the Experimental 
Analysis of Behavior . 6, 423-428. 

Azrin, N. H. (1961). Time-out from positive reinforcement. 
Science . 133 . 382-383. 

Azrin, N. H. , Hake, D. F. , Hutchinson, R. R. (1965). 

Elicitation of aggression by a physical blow. Journal 
of the Experimental Analysis of Behavior . 8, 55-57. 

Azrin, N. H. , Hutchinson, R. R. , & Hake, D. F. (1966). 
Extinction-induced aggression. Journal of the 
Experimental Analysis of Behavior . 9, 191-204. 

Azrin, N. H., Hutchinson, R. R. , & McLaughlin, R. (1965). 

The opportunity for aggression as an operant reinforcer 
during aversive stimulation. Journal of the 
Experimental Analysis of Behavior . 8, 171-180. 

Bloomfield, T. M. (1966) . Two types of behavioral contrast 
in discrimination learning. Journal of the 
Experimental Analysis of Behavior . 9, 155-161. 

Bond, N. (1973). Schedule-induced polydipsia as a function 
of the consummatory rate. Psychological Record . 23 . 
377-382. 



94 



95 

Bond, N. W. , Blackman, D. E. , & Scruton, P. (1973). 

Suppression of operant behavior and schedule-induced 
licking in rats. Journal of the Experimental Analysis 
of Behavior . 20 . 375-383. 

Bonem, M. & Grossman, E. K. (1988) . Elucidating the 

effects of reinforcement magnitude. Psychological 
Bulletin . 104 . 348-362. 

Branch, M. N., & Gollub, L. R. (1974). A detailed analysis 
of the effects of d-amphetamine on behavior under 
fixed-interval schedules. Journal of the Experimental 
Analysis of Behavior , 21 . 519-539. 

Brown, T. G. , & Flory, R. K. (1972). Schedule-induced 

escape from fixed-interval reinforcement. Journal of 
the Experimental Analysis of Behavior . 17 . 395-404. 

Burks, C. D. (1970) . Schedule-induced polydipsia: Are 
response-dependent schedules a limiting condition? 
Journal of the Experimental Analysis of Behavior , 13 , 
351-358. 

Carlisle, H, S. (1971). Fixed-ratio polydipsia: Thermal 
effects of drinking, pausing, and responding. Journal 
of Comparative and Physiological Psychology , 75 , 10-22. 

Catania, A. C. (1963). Concurrent performances: A 

baseline for the study of reinforcement magnitude. 
Journal of the Experimental Analysis of Behavior . 6 , 
299-300. 

Cherek, D. R. & Pickens, R. (1970) . Schedule-induced 

aggression as a function of fixed-ratio value. Journal 
of the Experimental Analysis of Behavior . 14 , 309-311. 

Cherek, D. R. , Thompson, T. , & Heistad, G. T. (1973). 
Responding maintained by the opportunity to attack 
during an interval food reinforcement schedule. 
Journal of the Experimental Analysis of Behavior . 19., 
113-123. 

Church, R. M. , LoLordo, V. M. , Overmier, J. B. , Solomon, R. 
L. , & Turner, L. H. (1966). Cardiac response to shock 
in curarized dogs. Journal of Comparative and 
Physiological Psychology , 62 . 1-7. 

Cohen, P. S. & Looney, T, A. (1973) . Schedule-induced 
mirror responding in the pigeon. Journal of the 
Experimental Analysis of Behavior , 19 , 395-408. 



96 

Couch, J. V. (1974) . Reinforcement magnitude and schedule- 
induced polydipsia: A reexamination. The 
Psychological Record . 24., 559-562. 

Dardano, J. F. (1973). Self-imposed time-outs under 
increasing response requirements. Journal of the 
Experimental Analysis of Behavior . 19, 269-287. 



de Villiers, P. (1977) . Choice in concurrent schedules and 
a quantitative formulation of the law of effect. In W. 
K. Honig & J. E. R. Staddon (Eds.), Handbook of operant 
behavior (pp. 233-237) . Englewood Cliffs, NJ: 
Prentice Hall. 

DeWeese, J., Webbe, F. M. , & Malagodi, E. F. (1972, April). 
Schedule-induced aggression using live target pigeons . 
Presented at the meeting of the Southeastern 
Psychological Association, Atlanta. 

Dove, L. D. (1976) . Relation between level of food 
deprivation and rate of schedule-induced attack. 
Journal of the Experimental Analysis of Behavior . 25 . 
63-68. 

Dove, L. D. , Rashotte, M, E., & Katz, H. N. (1974). 

Development and maintenance of attack in pigeons during 
variable-interval reinforcement of key pecking. 
Journal of the Experimental Analysis of Behavior . 21 . 
563-569. 

Dunham, P. J., (1971). Punishment: Method and theory. 
Psychological Review . 78, 58-71. 

Epstein, R. (1981) . Amount consumed as a function of 

magazine-cycle duration. Behaviour Analysis Letters . 
1, 63-66. 

Falk, J. L. (1961) . Production of polydipsia in normal 

rats by an intermittent food schedule. Science . 133 . 
195-196. 

Falk, J. L. (1966) . Schedule-induced polydipsia as a 
function of fixed interval length. Journal of the 
Experimental Analysis of Behavior . 9, 37-39. 

Falk, J. L. (1967) . Control of schedule-induced 

polydipsia: Type, size, and spacing of meals. Journal 
of the Experimental Analysis of Behavior . 10 . 199-206 



97 

Falk, J. L. (1969) , Conditions producing psychogenic 

polydipsia in animals. Annals of the New York Academy 
of Sciences . 157 . 569-593. 

Falk, J. L. (1971) . A theoretical review: the nature and 
determinants of adjunctive behavior. Physiology and 
Behavior . 6, 577-588. 

Fantino, E. , Squires, N. , Delbruck, N. , & Peterson, C. 

(1972) . Choice behavior and the accessibility of the 
reinforcer. Journal of the Experimental Analysis of 
Behavior . 18 . 35-44. 

Ferster, C. B. & Skinner, B. F. (1957) . Schedules of 

reinforcement . New York: Appleton-Century-Crofts. 

Flory, R. K. (1969a) . Attack behavior in a multiple fixed- 
ratio schedule of reinforcement. Psychonomic Science . 
16 . 156-157. 

Flory, R. K. (1969b) . Attack behavior as a function of 
minimum inter-food interval. Journal of the 
Experimental Analysis of Behavior . 12., 825-828. 

Flory, R. K. (1971) . The control of schedule-induced 

polydipsia: Frequency and magnitude of reinforcement. 
Learning and Motivation . 2, 215-227. 

Flory, R. K. , Robinson, J. K. , & Dunahoo, C. L. (1988, 

April) . The effects of covarying reinforcer magnitude 
and frequency on schedule-induced attack behavior . 
Presentation at the annual meeting of the Eastern 
Psychological Association, Buffalo. 

Freed, E. & Hymowitz , N. (1972). Effects of schedule, 
percent body weight, and magnitude of reinforcer on 
acquisition of schedule-induced polydipsia. 
Psychological Reports . 31 . 95-101, 

Gentry, W. D. (1968) . Fixed-ratio schedule-induced 

aggression. Journal of the Experimental Analysis of 
Behavior . 11 . 813-817. 

Gilbert, R. M. (1974). Ubiquity of schedule-induced 

polydipsia. Journal of the Experimental Analysis of 
Behavior . 21 . 277-284. 

Guttman, N. (1953). Operant conditioning, extinction, and 
periodic reinforcement in relation to concentration of 
sucrose used as reinforcing agent. Journal of 
Ex perimental Psychology . 46, 213-224. 



98 

Hawkins, T. D. , Schrot, J. F. , Githens, S. H. , & Everett, 
P. B. (1972). Schedule-induced polydipsia: An 
analysis of water and alcohol ingestion. In R. M. 
Gilbert & J. D. Keehn (Eds.), Schedule effects; Drucfs. 
drinking, and aggression (pp. 95-128) . Toronto: 
University of Toronto Press. 

Hutchinson, R. R. , Azrin, N. H. , & Hunt, G. M. (1968). 
Attack produced by intermittent reinforcement of a 
concurrent operant response. Journal of the 
Experimental Analysis of Behavior . 11, 489-495. 

Keehn, J. D. & Colotla, V. A. (1971) . Stimulus and subject 
control of schedule-induced drinking. Journal of the 
Experimental Analysis of Behavior . 16 , 257-262. 

Kelly, J. F. & Hake, D. F. (1970) . An extinction-induced 
increase in an aggressive response with humans. 
Journal of the Experimental Analysis of Behavior . 14 . 
153-164. 

Killeen, P. R. (1975) . On the temporal control of 
behavior. Psychological Review . 82 . 89-115. 

Killeen, P. R. , Hanson, S. J., & Osborne, S. R. (1978). 
Arousal: Its genesis and manifestation as response 
rate. Psychological Review . 85 , 571-581. 

Knutson, J. F. (1970) . Aggression during the fixed-ratio 
and extinction components of a multiple schedule of 
reinforcement. Journal of the Experimental Analysis of 
Behavior . 13, 221-231.. 

Lowe, C. F., Davey, G. C. , & Harzem, P. (1974). Effects of 
reinforcement magnitude on interval and ratio 
schedules. Journal of the Experimental Analysis of 
Behavior . 22, 553-560. 

Magyar, R. L. & Malagodi, E. F. (1980) . Measurement and 
development of schedule-induced drinking in pigeons. 
Physiology & Behavior . 25, 245-251. 

Malagodi, E. F. , Sicignano, A., & Allen, R. F. (1979, 
April) . An analysis of the role of the response 
reguirement as a determinant of schedule-induced 
attack . Paper presented at an annual meeting of the 
Southeastern Psychological Association, New Orleans. 

Malagodi, E. F. , Webbe, F. M. , & Waddell, F. R. (1975). 

Second-order schedules of token reinforcement: effects 
of varying the schedule of food presentation. Journal 
of the Experimental Analysis of Behavior . 24 . 173-181. 



99 



Merigan, W. H. , Miller, J. S., & Gollub, L. R. (1975). 
Short-component multiple schedules: Effects of 
relative reinforcement duration. Journal of the 
Experimental Analysis of Behavior , 24 , 183-189. 

Pear, J. J. & Wilkie, D. M. (1971) . Contrast and induction 
in rats on multiple schedules. Journal of the 
Experimental Analysis of Behavior . 15 . 289-296. 

Powell, J., Martindale, A., & Kulp, S. (1975). An 
evaluation of time-sample measures of behavior. 
Journal of Applied Behavior Analysis . 8, 463-469. 

Reid, A. K. & Dale, R. H. I. (1983). Dynamic effects of 
food magnitude on interim-terminal interaction. 
Journal of the Experimental Analysis of Behavior . 39 . 
135-148. 

Reid, A. K. & Staddon, J. E. R. (1982) . Schedule-induced 
drinking: Elicitation, anticipation, or behavioral 
interaction? Journal of the Experimental Analysis of 
Behavior . 38 . 1-18. 

Reynolds, G. S. (1961). Behavioral contrast. Journal of 
the Experimental Analysis of Behavior . 4, 57-71. 

Richards, R. W. & Rilling, M. (1972). Aversive aspects of 
a fixed-interval schedule of food reinforcement. 
Journal of the Experimental Analysis of Behavior . 17 . 
405-411. 

Roper, T. J. & Nieto, J. (1979) . Schedule-induced drinking 
and other behavior in the rat, as a function of body 
weight deficit. Physiology and Behavior . 23 . 673-678. 

Rosellini, R. A. & Burdette, D. R. (1980) . Meal size and 

intermeal interval both regulate schedule-induced water 

intake in rats. Animal Learning and Behavior . 8, 647- 
652. 

Schneider, B. A. (1969) . A two-state analysis of fixed- 
interval responding in the pigeon. Journal of the 
Experimental Analysis of Behavior . 12., 677-688. 

Segal, E. F., Oden, D. L. , & Deadwyler, S. A. (1965). 

Determinants of polydipsia: IV. Free-reinforcement 
schedules. Psychonomic Science , 3, 11-12. 

Solomon, R. L. & Corbit, J. D. (1974) . An opponent-process 
theory of motivation: I. Temporal dynamics of affect. 
Psychological Review . 81 . 119-145. 



100 



Sherrington, C. S. (1906). The integrative action of the 

nervous systein . New Haven, CT: Yale University Press. 

Staddon, J. E. R. (1970) . Effect of reinforcement duration 
of fixed-interval responding. Journal of the 
Experimental Analysis of Behavior . 13 . 9-11. 

Staddon, J. E. R. (1977) . Schedule-induced behavior. In 
W. K. Honig & J. E. R. Staddon (Eds.), Handbook of 
operant behavior (pp. 125-148) . Englewood Cliffs, NJ: 
Prentice-Hall . 

Staddon, J. E. R. & Ayres, S. L. (1975). Sequential and 
temporal properties of behavior induced by a schedule 
of periodic food delivery. Behaviour , 54, 26-49. 

Staddon, J. E. R. & Simmelhag, V. L. (1971) . The 

"superstition" experiment: A re-examination of its 
implications for the principles of adaptive behavior. 
Psychological Review , 78, 3-43. 

Tedeschi, R. E. (1959) . Effects of various centrally 

acting drugs on fighting behavior of mice. Journal of 
Pharmacology and Experimental Therapeutics , 125 , 28. 

Terrace, H. S. (1963) . Discrimination learning with and 

without "errors." Journal of the Experimental analysis 
of Behavior . 6, 1-27. 

Terrace, H. S. (1964) . Wavelength generalization after 
discrimination learning with and without errors. 
Science , 144 , 78-80. 

Thompson, D. M. (1964) . Escape from S° associated with 

fixed-ratio reinforcement. Journal of the Experimental 
Analysis of Behavior . 7, 1-8. 

Ulrich, R. E. & Azrin, N. H. (1962) . Reflexive fighting in 
response to aversive stimulation. Journal of the 
Experimental Analysis of Behavior . 5, 511-520. 

Wayner, M. J. & Rondeau, D. B. (1976) . Schedule dependent 
and schedule induced behavior at reduced and recovered 
body weight. Physiology and Behavior . 17, 325-336. 

Webbe, F. M. , DeWeese, J. & Malagodi, E. F. (1974). 
Induced attacking during multiple fixed-ratio, 
variable-ratio schedules of reinforcement. Journal of 
the Experimental Analysis of Behavior . 22., 197-206. 



101 

Wetherington, C. L. (1979) . Schedule-induced drinking: 
Rate of food delivery and Herrnstein's equation. 
Journal of the Experimental Analysis of Behavior . 32 , 
323-333. 

Wetherington, C. L. (1982) . Is adjunctive behavior a third 
class of behavior? Neuroscience & Biobehavioral 
Reviews , 6, 329-350. 

Yoburn, B. C. & Flory, R. K. (1977) . Schedule-induced 

polydipsia and reinforcement magnitude. Physiology and 
Behavior . 18 . 787-791. 

Zeiler, M. D. (1977) . Schedules of reinforcement: The 
controlling variables. In W. K. Honig & J. E. R. 
Staddon (Eds.), Handbook of operant behavior (pp. 201- 
232). Englewood Cliffs, NJ: Prentice-Hall. 

Zimmerman, D. W. (1971) . Rate changes after unscheduled 

omission and presentation of reinforcement. Journal of 
the Experimental Analysis of Behavior . 15 . 261-270. 



BIOGRAPHICAL SKETCH 

Raymond C. Pitts was born in Jacksonville, FL on July 
10, 1957 to R. C. and Nita Pitts. After graduation from 
Jacksonville's Terry Parker High School in 1975, he moved to 
Gainesville, FL and enrolled in the University of Florida. 
Ray graduated with a B.A. in 1980, and an M.S. in 1986, both 
in psychology and both from the University of Florida. He 
plans to receive his Ph.D. in December of 1989. 



102 



I certify that I have read this study and that in my 
opinion it conforms to acceptable standards of scholarly 
presentation and is fully adequate, in scope and quality, as 
a dissertation for the degree of Doctor of Philosophy. 



f 



-y- v^:-'^ 



E. F. Malagodi, /Chairman 
Professor of Psychology 

I certify that I have read this study and that in my 
opinion it conforms to acceptable standards of scholarly 
presentation and is fully adequate, in scope and quality, as 
a dissertation for the degree of Doctor of Philosophy. 

Marc N. Branch 
Professor of Psychology 

I certify that I have read this study and that in my 
opinion it conforms to acceptable standards of scholarly 
presentation and is fully adequate, in scope and quality, as 
a dissertation for the degree of Doctor of Philosophy. 




/Brian^A. LWata 
''^Professor/' of Psychology 

I certify that I have read this study an d tha t in my 
opinion it conforms to acceptable standarda^'^f sclT&i^rly 
presentation and is fully adequate, in scope and quality, as 
a dissertation for the degree of Doctor of Philosophy^. 



a^ 




i^ypacker 
Professor of Psychology 



I certify that I have read this study and that in my 
opinion it conforms to acceptable standards of scholarly 
presentation and is fully adequate, in scope and quality, as 
a dissertation for the degree of Doctor of Philosot 




Donald J./Stehouwer 
Associate Professor of 
Psychology 



I certify that I have read this study and that in my 
opinion it conforms to acceptable standards of scholarly 
presentation and is fully adequate, in scope and quality, as 
a dissertation for the degree of Doctor of Philosophy. 




?illiam D. Wolking 
Professor of Educaliion 



This dissertation was submitted to the Graduate Faculty 
of the Department of Psychology in the College of Liberal 
Arts and Sciences and to the Graduate School and was 
accepted as partial fulfillment of the requirements for the 
degree of Doctor of Philosophy. 



December, 1989 



Dean, Graduate School 



UNIVERSITY OF FLORIDA 



3 1262 08553 7701