THE SLEEP NEED: SLEEP DEPRIVATION IN THE RAT By ROBERT ALAN LEVITT A DISSERTATION PRESENTED TO THE GRADUATE COUNQL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA August, 1965 ^SM UNIVERSITY OF FLORIDA 3 1262 08552 4121 ACKNOWLEDGiyiENTS The author wishes to express his gratitude to Dr. Wilse B. Webb for stimulating the research idea and to Dr. Bradford N. Bunnell for supervising the conduct of the research. The author also wishes to acknowledge the advice and council of Drs . Frederick A. King, Henry S. Pennypacker, Robert L. King, and James A. Horel. He also wishes to express his appreciation to his wife, Phyllis, for her patience and assistance in the typing of this manuscript. The help of Frank Johnson, William Walker, Mario Perez, Lester Cohan, Barbara Weise, and Alan Goldstein in data gathering and scoring is also gratefully acknowledged. 11 TABLE OF CONTENTS Page ACKNOWLEDGMENTS ii LIST OF TABLES iv LIST OF FIGURES vi INTRODUCTION 1 EXPERIMENT I: THE DEVELOPMENT OF AN ULTRASONIC ACTIVITY DEVICE TO MEASURE SLEEP AND WAKING IN THE RAT 13 EXPERIMENT II: THE EFFECT OF DEXTRO-AMPHETAMINE INDUCED SLEEP DEPRIVATION ON THE SLEEP CYCLE (ACTIVITY MEASURE) 28 EXPERIMENT III: EEG AND BEHAVIORAL OBSERVATION ON RATS WALKING THE WATER- IMMERSED TREADMILL 53 EXPERIMENT IV: THE EFFECT OF TREADMILL INDUCED SLEEP DEPRIVATION ON THE SLEEP CYCLE {ACTIVITY MEASURE) 62 EXPERIMENT V: DEXTRO-AMPHETAMINE OR TREADMILL INDUCED SLEEP DEPRIVATION AND EEG MEASURED SLEEP CYCLE 68 SUMMARY AND CONCLUSIONS 84 APPENDICES 95 REFERENCES 110 BIOGRAPHICAL SKETCH 114 111 LIST OF TABLES Table ^^2^ 1. An Activity Scoring System 22 2. Agreement Between Individual Samples of Correlated EEG-Activity Records 24 3. Averaged Data on Sleep Cycle and EEG- Activity Correlation from Experiment I . . . 2 5 4. Recording Schedule for the Deprivation Groups in Experiment II 34 5. Estimated Post-Dextro-Amphetamine Deprivation Compensation 40 6. Mean Percentage of Daily Sleep Obtained During Lighted Hours 43 7 . Mean Percentage of Daily Food Intake Obtained During Dark Hours 50 8. Mean Percentage of Daily Water Intake Obtained During Dark Hours 51 9. Recording Schedule for the Deprivation Groups in Experiment IV 63 10. Estimated Post-Treadmill Deprivation Compensation 66 11. Sleep Cycle Totals Before and After Deprivation "72 12. Estimated Post-Deprivation Compensation . . 7 3 APPENDIX A ANALYSES OF VARIANCE 13 . Dextro-Amphetamine Induced Deprivation and Sleep Cycle 96 14. Dextro-Amphetamine Deprivation and Food Intake 97 ( iv Table Page 15. Dextro- Amphetamine Deprivation and Water Intake 98 16 . Dextro-Amphetamine Deprivation and Body Weight 99 17. Treadmill Induced Deprivation and Sleep Cycle 100 18. Dextro-Amphetamine or Treadmill Induced Deprivation and Sleep Cycle 101 19. Mean Length of Sleep Epoch as a Function of Sleep Deprivation 102 ZO. Length, Frequency, and Percentage of Paradoxical Sleep as a Function of Sleep Deprivation 10 3 LIST OF FIGURES Figure 1, T^T I . Page The Pendulum- type Calibrator 16 2. The Environmental Enclosure and Ultrasonic Activity Unit 18 3. The Environmental Enclosure with Calibrator in Position ^'^ 4. EEG Recordings from Two Rats 29 5. Dextro-Amphetamine Deprivation Experiment: Daily Sleep Time 3 6 6. Dextro-Amphetamine Deprivation Experiment: Circadian Rhythm 37 Mean Minutes Sleep Obtained per Subject During Dextro-Amphetamine Deprivation ... 45 8. Minutes Sleep Deprivation per Dextro- Amphetamine Injection 45 9. Food Intake During Dextro-Amphetamine Experiment 47 10. Water Intake During Dextro-Amphetamine Experiment 48 11. Body Weight During Dextro-Amphetamine Experiment 49 12. Micro-Sleep Prevalence During Treadmill Deprivation 55 13. Micro-Sleep and Behavioral Motionlessness on the Sleep Deprivation Treadmill 58 14. Treadmill Deprivation Experiment: Daily Sleep Time 64 15. Treadmill Deprivation Experiment: Circadian Rhythm 65 vi Figure Page 16. Dextro-Amphetamine or Treadmill Deprivation and Sleep Cycle: Waking, Paradoxical Sleep, and Normal Sleep .... 74 17. Post-Deprivation Sleep-Waking Cycle as a Percentage Change from Control Values ... 77 18. Length of Sleep Epochs 79 19. Length of Paradoxical Sleep Bursts .... 79 20. Minutes of Slow Wave Sleep Separating Paradoxical Sleep Bursts 81 21. Percentage of Total Sleep Time Spent in Paradoxical Sleep 81 22. Minutes into Sleep Epoch When First Minute of Paradoxical Sleep Occurs 82 23. Difference Between Observed and Expected Awakenings from Paradoxical Sleep 82 Vll INTRODUCTION Using as our criterion the time spent in consummatory activity, sleep is by far the most important of man's activities (Gofer & Appley, 1964) . And yet, although sleep is presently receiving a great deal of experimental atten- tion, little is known of its biological function. Sir John Eccles, in opening an international symposium on sleep, put it this way. "When we consider the immense human signifi- cance of sleep, the absolute necessity for us to spend a considerable part of our lives in abject mental annihilation, it is remarkable how little we know about it, how little we can say to account for the necessity of sleep" (Eccles, I960, p. 1) . The experiments to be reported in this paper are a beginning on an analysis of the necessity for sleep. The method utilized is to produce a heightened need through deprivation of sleep and to study the changes in behavior following this deprivation. The extirpation of an organ has long been a recognized method of determining function. Depriving the organism of a particular bodily activity (sleep) is the functional counterpart (Kleitman, 1963). The dependent variable in these experiments is the characteristics of the sleep cycle as measured electro- physiologically or by means of an activity measuring unit. The basic assumption underlying this research is that the compensatory changes following sleep deprivation are part of the homeostatic bodily mechanisms which function during sleep. A number of investigators have suggested the existence of stages or levels of sleep. It may be that these various stages of sleep subserve different bodily functions . Stages The first major human electroencephalographic ( EEG) study of sleep was made by Loomis, Harvey, and Hobart (1937) . They classified the EEG into five stages, A to E, of increasing sleep depth. Other investigators have preferred somewhat different classifications (Kleitman, 1963; Oswald, 1962). The waking EEG is of a low ampli- ♦^ tude and high frequency. As the depth of sleep increases f,{ from stages A through E or 1 through 4) , the amplitude increases and the frequency is reduced. Although most 'investigators have assumed that the function of sleep is accomplished mostly at increasing depths, at the present time no separate functions can be attributed to the different stages. The most that can be said for the function of sleep is that investigators tend to assume a restorative one, allowing the recovery from deficits produced by waking activity {Kleitman, 1963; Oswald, 1962). However, new evidence has suggested a specific function for at least one stage of sleep. Dreaming. — In recent years attention has been directed to a stage of sleep designated the rapid eye movement phase (REMP) . This stage has also been called paradoxical, acti- vated, rhinencephalic, or low voltage fast sleep (LVFS) . These terms will be used interchangeably in this paper. REM sleep was first described in human subjects by Aserinsky and Kleitman in 1953. Since then, an analogous stage of sleep has been described in a number of other species, including the cat (Dement, 1958) and the rat (Hall, 1963; Swisher, 1962) . When Aserinsky and Kleitman (1953) awoke subjects from the different stages of sleep including the REMP, they made the exciting discovery that dreams were reported about 80 per cent of the time when the awakening interrupted REM sleep but only about 20 per cent when the awakening inter- rupted other sleep stages. This discovery led to a number of studies exploring this relationship (Dement, 1955; Dement & Kleitman, 1957a). Dement (1965), upon reviewing the evidence on dreaming, has concluded that although the probability of dream recall and by inference the probability of dreaming is much higher in REM than non-REM (NREM) sleep, dreams do occur during NREM sleep. However, Dement has .suggested that REM and NREM dreams differ in their essential - nature with only REM dreams consisting of perceptual experi- ences (Class I experiencing) . He has theorized that, "during the REM phase of sleep the brain is somehow generating the neurophysiological background for Class I experiencing" (Dement, 1965, p. 203). NREM dreams consist only of Class II experiencing (abstract thought, imagery) not dependent on sensory input. Thus, during REM dreams the brain is generating its own sensory input. Dement (1965) and Jouvet (I960) have suggested the existence of two qualitatively different phases of sleep. Sleep phases. — Jouvet (I960; Jouvet & Jouvet , 1963) has demonstrated that the paradoxical phase of sleep is triggered by an area in the caudal brain stem. He has called this phase rhombencephalic sleep to differentiate it froiTi slow wave sleep which" he believes is telencephalic in origin. The paradoxical nature o'f rhombencephalic sleep is that the EEG is one of waking or light sleep, but the depth of sleep as determined by arousal threshold is deeper than during any other stage (Dement & Kleitman, 1957b; Dillon & Webb, in press) . Both Dement (1965) and Jouvet (I960) have concluded that there are two entirely distinct phases of sleep. One of these phases is the REM stage and the other is all the slov/ wave sleep that precedes it. Dement (1965) has suggested that physiological variations within NREM sleep are essentially quantitative and do not warrant further subdivision. These two phases may be expected to subserve differing functions and may respond independently to experimental manipulations. The measurement of sleep Until now there have been two means of measuring the sleep cycle, behavioral observation and the electroencephalo- graph. Both of these methods have severe disadvantages. Behavioral observation requires the continuing presence of an observer to make a subjective judgment of whether the subject (_S) is asleep or awake- The experimenter's very presence is likely to disturb the sleep cycle and also means a great expense in man hours. For this expense only a subjective judgment of sleep or waking is produced. The EEG surmounts two of these difficulties; levels of sleep are discriminable and the judgment is objective. .However, these advantages are obtained at considerable expense. An observer must constantly be present to monitor the equipment, and electrodes need to be attached to the su'^ject. In the case of the rat, the animal used in these studies, the recording electrodes usually are surgically implanted under the skull. These electrodes are likely to alter somewhat the nature of the response being measured. This large expense in observer and equipment severely limits the length of EEG recording that it is practical to obtain. As an alternative, the first experiment reported here presents an activity measuring device for recording sleep and wak:i-ng. This method has the advantage that it is inexpensive, relative to the EEG, and does not require the continuing presence of an experimenter. This activity system may be operated continually for long periods of time. Since the activity system has the disadvantage of being unable to discriminate phases of sleep, both activity and EEG recording were used in these experiments. The production of sleep deprivation Another difficulty which had to be surmounted was that of producing sleep deprivation. Licklider and Bunch (1946) were unable to keep rats awake on beds of nails, but thought they could successfully maintain wakefulness by forcing the _Ss to walk a treadmill partially submerged in water. The rats died after 3 to 14 days on the treadmill probably, at least partially, from fighting with each other (the rats were not in separate compartments) . Evidence to be reported in this paper raises serious questions as to the effective- ness of the treadmill as a method of producing sleep depri- vation. Svorad and Novikova ( I960) have reported successfully producing sleep deprivation lasting seven days in rats by periodically administering dextro-amphetamine. The authors do not state their criterion of sleep deprivation, nor do they report data on the sleep cycle in their S^s . This procedure was part of a study on the effect of sleep deprivation on an experimentally induced neurosis in the rat. In a preliminary study the present author was successful in replicating the finding of Svorad and Novikova that sleep deprivation could be produced in rats with dextro-amphetamine. According to Beckman { 1961) dextro-amphetamine is used clinically, principally as a stimulant of the central nervous system and for its anorexigenic effect in the treatment of obesity. Bradley and Elkes (1957) have found a correlated EEG desynchronization and behavioral alertness to follow systemic dextro-amphetamine administration. This arousal was like that following electrical reticular forma- tion stimulation and was dependent on an intact mesencephalon for its occurrence, implicating receptors in the ascending reticular activating system. Williams, Lubin, and Goodnow (1959) have studied the effects of sleep loss in humans on performance at skilled tasks. They felt the impaired performance was due to the occurrence of brief sleep episodes in sleep deprived subjects during performance. This interpretation is sup- ported by the experiments of Kornetsky, Mirsky, Kessler, and Dorff (1959), who found that dextro-amphetamine, which stimulates the reticular formation, greatly reduces performance irapairment in sleep deprived _Ss . 8 The results of sleep deprivation The only report of a change in sleep behavior follow- ing sleep deprivation in the rat is that of Webb (1957), who found that rats sleep deprived on a water- immersed treadmill had shorter "sleep latencies" (time to fall asleep) than during control tests. Kleitman (1963) and Oswald (1962) have reported an increase in sleep time following prolonged sleep deprivation in humans. This increase is not equal to the amount of sleep lost, but amounts to about 11 to 14 hours sleep the first night following up to 65 hours sleep deprivation. Berger and Oswald (1962) and Williams, Hammack, Daly, Dement, and Lubin (1963) have reported data on changes in the EEG stages of sleep following deprivation. Both studies reported an increase in stage 4 on the first recovery night, followed by an increase in REM sleep on the second recovery night. The authors of these articles infer that these rebound effects reflect an underlying "need" state of the organism. Webb and Agnew (1965), in an experiment on continued partial sleep deprivation in the human, found an increase in stage 4 sleep. This increase was at the expense, primarily, of stage 3 with essentially no change in REM or stage 2 sleep as a percentage of total sleep- This result is probably due to the S_s being allowed only three hours sleep per night. Since the stage 4 "need" apparently takes precedence over the REM "need, " the ^s did not have time to compensate for the REM loss. Oswald ( 1962) has suggested that there may not be a fundamental requirement for adult humans to spend 8 out of every 24 hours asleep, since deprived subjects make up only a fraction of the deficit on the first night. It would seem this question cannot be answered at the present, since compensatory changes in sleep behavior may continue to occur for a number of days following deprivation. However, it may be that there is a difference in the "value" of the various stages or phases of sleep in alleviating a large sleep debt, and that following sleep deprivation the "most valuable" kind of sleep will occur in greater quantity than normal . If, in fact, as Dement and Jouvet have suggested there are two distinct sleep phases differing in function, then this assumption of a change in sleep characteristics follow- ing total sleep deprivation is reasonable. There are a number of reports of deprivation of one or another stage of sleep. Dement (I960) has reported that REM (dream) deprivation by awakening human subjects every time they enter REM sleep for five consecutive nights results in the need for an increased number of awakenings on successive nights in order to prevent occurrences of REM sleep. He also found a compensatory increase in REM time following 10 . - deprivation. Dement also reported REM deprivation, to produce "personality disturbances" in the subjects, to a degree that some subjects were forced to terminate this part of the experiment. These personality disturbances occurred in spite of a normal, or near normal, level of total sleep and did not occur when, in a control study, the same _Ss were awakened only from NREM sleep. These findings have recently been replicated by Siegel and Gordon (1965) in the cat and Khazan and Sawyer (1963) in the rabbit. Siegel and Gordon's _Ss required an increased number of awakenings on successive days of depri- vation in order to prevent paradoxical sleep, and compensated for the deprivation with an increased amount of paradoxical sleep after deprivation was discontinued. Siegel and Gordon recorded EEGs for 10 to 12 hours a day during a so-called "sleep period." Paradoxical sleep deprivation during this sleep period was produced by electrical stimulation of the reticular formation each time the S_ entered paradoxical sleep. During the other 12 to 14 hours per day, the authors report keeping the cats awake by placing them on a brick in the middle of a pan of water, which was the floor of the cage. Khazan and Sawyer (1963) discovered that a constant loud noise ( 80 decibels) would almost obliterate paradoxical sleep without influencing the amount of slow wave sleep. Following 20 hours of paradoxical sleep deprivation, a rebour. „. increase occurred. After 20 hours, the paradoxical 11 i.le:,T3 ir.hi>oition produced by tr-e viiita noice tended to adsipt out . Agnew, Webb, and Williams (1964) have reported -a compensatory increase in stage 4 sleep following depriva- tion of this sleep stage in humans. Current sleep research is centered on the iraportance and function of these tv/o stages of sleep, REM and stage 4. In order to answer the questions of (a) the length of time that comjpensatory changes continue follov/ing total sleep deprivation, (b) the amount of total compensation that occurs, and ( c) the possibility of changes in the phase characteristics of sleep following total sleep depri- vation, the following experiments were undertaken. The first experiment details the design and develop- ment of an activity system to record the sleep cycle in small mairanals . Experiment II studies the effect of varying lengths of dextro-amphetamine induced sleep deprivation on the sleep cycle m.easured by the ultrasonic activity units. Experin.ent III is concerned v/ith the character of the EEG of rats walking on -che water-imir^ersed treadmill. Previous behavioral observation had suggested that rats may get s:.me sleep on the treadmill, and this observation v;as con- firmed in Experime/- III. In spite of this finding, in Experiraent IV sleep cycle was measured before and after treaamill deprivation usxng the activity units. It was 12 thought that although the S_s did obtain some sleep, the amount was less than normal, and this might be evident in post-deprivation compensation. In Experiment V sleep cycle was measured before and after dextro-amphetamine or treadmill deprivation, but the EEG was used instead of the activity units. Although it is not now considered reasonable to record EEG for the lengths of time we use the activity units, it was possible to get 24-hours ' data before and after deprivation. Although these data are not as stable or reliable as the activity data, the EEG does permit the differentiation of paradoxical from slow wave sleep. These experiments have required lengthy normative sleep cycle recording and enable the detailing of the normal parameters of sleep in our subject population. EXPERIMENT I THE DEVELOPMENT OF AN ULTRASONIC ACTIVITY DEVICE TO MEASURE SLEEP AND WAKING IN THE RAT Dillon (1963) used an ultrasonic recording device . developed by Peacock and Williams (1962) to record sleep- ing and waking in the rat. Higgins (1964) has built a transistorized version of the Peacock and Williams unit. This experiment presents the methodology for an ultrasonic activity measure of sleep. The system is a modification of Dillon's. A simple scoring system has been developed, a pendulum-type calibrator for adjusting sensitivity has been designed and tested, and permanent enclosures for the system have been built. Using these modifications a series of correlated EEG-activity recordings were collected. Method Subjects Six ir.ale Long-Evans hooded rats were used. Three were 90-100 and three 180-200 days old. They were maintained on ad-lib. food and water throughout the experiment. Apparatus Sleep and waking were determined by a Grass-III-D 13 14 EEG unit. Behavioral observations were periodically- recorded on the EEG record. Each minute was scored for waking, slow wave sleep, or paradoxical sleep. Whichever of tliese was most prevalent was the condition assigned to that minute. Activity was measured with an ultrasonic device developed by Peacock and Williams (1962) or a transistorized version built by Alton Electronics (Higgins, 1964) . These activity devices are intended for use in detecting the movement of small mammals . The devices are usable within a one-cubic yard area. The Peacock and Williams unit con- sists of a transmitting transducer, receiving transducer, power supply, and readout unit. The readout drives an ink writing recorder. In the Alton units the power supply drives the recorder directly. The principle of operation is as follows. A 40- kilocycle sine wave signal is generated by the transmitter and radiated as ultrasonic sound (nonaudible) into the test volume by the transmitting transducer. These sound waves permeate the experimental volume, being reflected from its walls and from objects within the experimental volume. At the receiver a transducer picks up the sound waves, converting them back into electrical signals which are then amplified. Any motion within the experimental volume into , which the sound wave is directed produces disturbances in 15 •the received portion of the wave, causing the receiver to produce electrical pulses. These electrical pulses may be recorded directly on a strip chart recorder (Alton unit) or (Peacock and Williams unit) used to operate a relay which in turn may operate a recording device (Higgins, 1964) . The ink writing recorder is an Esterline-Angus Opera- tion Recorder, Model AW. The magnitude of movement which causes a pulse can be adjusted through a broad range of behavior by manipula- ting a sensitivity control. Calibration The activity units have a sensitivity adjustment for controlling the level of activity that will activate the system. A pendulum-type calibrator was used to determine the sensitivity. Figure 1 is a dimensional diagram of this calibrator. The pendulum was manually held at a given distance from the vertical and then released. The distance between the swing adjustment and pendulum screw in these experiments was 0.20 inch. The time from release until the activity unit stopped responding to the decreasing motion was the unit of calibration. A reading was made •immediately before data collection began, and this reading was the calibration setting. A goal of this experiment was to determine the range of sensitivity settings at which an 16 , 2 o < > cr Q. u o I ''^ O a. CM . * I- < > CM Q. iLi o I UJ a: (L • • n -p u c 0 (U u e 0) •rH M n Q) >i & iH •H U c 0 U) •rH 0) -P ■P fd D > C •H •H ^^ £ a Q) o Q o CO 0) * .H >- c • < -H 0) M-i o e e 0 rO rH +J Eh -P (U P ,c; a 0 D< q; 1 0) I en (1) 0 .H u >i m 4J -H X H w 0) n 0) Q Q ■P 3 C • •H ITI E 0) C >H nJ 3 (U CJi S o o o o o O O CO o o d33ns S3inNm 37 00 •• cn +J c c •H Z i •0 (0 o •H 0 < 04 rec > X tr ElI 0) 4J Q. c 3 UJ 0 C o •H •H ^ 1 +J e t- ^ o V) •H o o S-l vO a. 0) rC 05 Q >- (1) * 0) CNJ < C • Q •H E kW e ^ o nJ ■P ■P >i 4J 0) S 3 O ft 2 ft * O 1 -r^ 0 TJ rH < > V u (1) ■H (1) q: Q O ■P 3 c UJ • •H CM a 1 vO o UJ 0) C -H q: M (0 M a. 3 0) 0) 2 ft * o o o o o o d33nS S3inNllM 38 These animals slept an average of 68 per cent of the time (811 minutes out of 1,200 minutes recorded). They slept 80 per cent of the day (483 minutes out of 600 minutes recorded) and 55 per cent of the night (328 minutes out of 60 0 minutes recorded) . The S_s obtained a mean of 60 per cent of their total sleep during the day and 40 per cent during the night. Sleep deprivation effects The significant circadian rhythm continued throughout the experiment. However, this rhythm was considerably reduced following deprivation. Figure 6 shows these effects. Sleep deprivation did increase sleep time above the pre- deprivation level; however, this effect is statistically significant only during the first four post-deprivation days . There is no difference in total compensatory sleep due to deprivation level (24, 72, or 120 hours). This can be seen in Figure 5 where there is no divergence in sleep time between the deprivation level groups. The days' effect is significant on days 5-8 post-deprivation, but not on days 1-4 post-deprivation. However, it can be seen in Figure 5 that sleep time is considerably elevated on day one post-deprivation, and gradually returns to the pre-deprivation level. The 24- and 120-hour deprivation groups return to a level of daily total sleep within their 39 pre-deprivation range on day 7 post-deprivation, and the 7 2-hour group does this on day 6 post-deprivation. Table 5 is an attempt to estimate the average amount of com- pensatory sleep obtained by each deprivation group. Com- pensation is arbitrarily considered to have ended on the first day that the mean sleep time for a deprivation group overlaps its pre-deprivation range. The most important point to be made is that total compensation is not sig- nificantly different between the deprivation groups. Depri- vation level failed to have an effect in spite of the sleep deprivation periods being 3 and 5 times as long, respectively, in the 7 2- and 120-hour groups as in the 24-hour deprivation group. Again, there is no increase in amount of compensatory sleep obtained with increasing sleep deprivation. There are two possible confounding influences which may accoiint for this finding. The first is shown in Figure 7. Although the amount of sleep obtained during depriva- tion was small throughout the drug-injection period, the amount of sleep obtained does increase after the first day. This may be due to the increasing sleep need of the Ss as the deprivation period progressed. It seems possible that during this high need state one minute of sleep may be "more valuable" in reducing the post-deprivation com- pensation than would normally be expected. However, this 40 TABLE 5 Estimated Post-Dextro-Amphetamine Deprivation Compensation 24-hour 7Z-hour 120-hour group group group Mean pre-deprivation sleep time (minutes) Days of deprivation Minutes sleep loss 784 839 794 1 3 5 784 2,517 3,970 Post-deprivation compensation* Total compensation Per cent compensation Day 1 218 113 117 2 150 99 194 3 186 133 49 4 85 54 88 5 117 51 50' 6 73 - 70 829 450 568 n (100%) 18% 14% * Minutes sleep above the pre-deprivation mean, 41 sleep during deprivation amounts to only about 20 minutes per day, which is a very small amount when compared to the 80 0 minutes sleep these animals normally get each day. It se. unlikely that this small amount of sleep would be sufficient to eliminate increasing compensation with increasing amounts of deprivation. Another consideration is a possible interaction between the hunger and sleep drives following dextro- amphetamine. In Figures 9 and 11 it can be seen that the drug reduced food intake -and body weight considerably, suggesting that after deprivation the _Ss may awaken to eat because of a strong hunger drive. This could have changed the relationship between hours of drug administration and compensatory sleep. However, it can be seen in Figure 9 that food intake did not increase above normal after depri- vation. Actually, food intake appears to be slightly depressed. This may be due to stomach shrinkage during the drug treatment. If stomach shrinkage did occur, it is possible that the _Ss ate more frequently, but consumed smaller amounts at each "meal." A curious effect is illustrated in Figure 6. There is no increase in sleep time during the post-deprivation light period. As a matter of fact, there is a slight decrease in sleeping time during the day. The entire compensation is accounted for by an increased sleep time 42 during the dark or night phase of the light cycle. An explanation of this phenomenon may be that the rat, being a nocturnal creature, sleeps maximally during the day, awakening only to satisfy other need states which require attention. The rat, according to this hypothesis, cannot constantly remain asleep for 8-12 hours because of other need requirements. Thus, only at night is there time available to compensate for the heightened sleep need. Only at night does the rat indulge in activities which can be curtailed to satisfy an increased need. Table 6 illustrates the circadian rhythm reduction following dextro-amphetamine administration. This effect is particularly noticeable at the longer periods of depri- vation. The _Ss in the 120-hour group obtained 61 per cent of their daily sleep during the daylight period on the control days and only 54 per cent on days 5-8 post-deprivation. Two of these S_s had their sleep cycles recorded on days 19 and 20 following 120-hours deprivation. These are not the same S_s who received a drug injection on day 11 post- deprivation (see below) . A 57 per cent figure for these two days suggests that this is only a temporary effect. This circadian rhythm reduction was not observed in the treadmill deprivation study (Experiment IV), suggesting that it is specifically related to the drug treatment. 43 Since the reduction continues after post-deprivation compensation has ended, the reduction cannot simply be accounted for by an increased amount of night sleep with no change in day sleep. On days 7 and 8 post-deprivation (Figure 6) after compensation has ended, the S_s are obtain- ing normal amounts of total sleep, but this amount is achieved by sleeping less than normal during the day and more than normal during the night. TABLE 6 Mean Percentage of Daily Sleep Obtained During Lighted Hours Days Deprivation level 24-hours 7 2-hours 120-hours Pre-deprivation (1-4) 59% 59% 61% Post-deprivation (1-4) 53 53 52 (5-8) 57 53 54 (19-20) - - 57 Sleep during drug administration Figure 7 shows the mean minutes sleep over days during deprivation. The diurnal, days and subjects variations were not statistically significant, although there does appear to be an increase in sleep time over days, especially 44 between day 1 and days 2 to 5 . On the average the _Ss received about 3 per cent of their normal daily sleep time during deprivation. Injection parameters Figure 8 is a graph of the mean length of sleep deprivation per injection over the five deprivation days. An analysis of the original waking times showed the decrease in length of drug action over days to be significant (p < .01) . This effect could be due either to true drug tolerance or to an increased sleep need produced by the increasing deprivation. As a possible test of these alternatives, a tolerance test was conducted on six of the _Ss { two at each deprivation level) 11 days following drug withdrawal. A single injection of dextro-amphetaraine was administered and the length of its action determined. The mean length of wakefulness during the tolerance test was 357 minutes compared to a mean of 3 54 minutes for the drug on deprivation day one. It appears that the S_s drug responsiveness had returned to its initial level; thus, it is not possible to choose between the alternatives. This effect may be due to the dissipation of either toler- ance or sleep need. If the length of drug effect had still been shortened, tolerance would be suggested since indications are that the sleep need is normal on day 11 post-deprivation (the 120-hour _Ss used in this test 45 40 -, a. UJ LJ _i tn UJ I- 3 20- -T- 2 -r- 4 DAYS Figure 7. Mean Minutes Sleep Obtained per Subject During Dextro-Amphetamine Deprivation. 400 Ui UJ \- 3 200- 0 J- DAYS Figure 8. Minutes Sleep Deprivation per Dextro-Amphetamine Injection. 46 were not the same rats as those whose sleep cycle was recorded on days 19 and 20 post-deprivation) . Drug toxicity Some of the S_s in the 7 2- and 120-hour deprivation groups lost some toes during deprivation. The paws became white, and the _Ss constantly worried and nibbled at them during deprivation. The most likely explanation for this seems to be that the dextro-amphetamine produced peripheral vasoconstriction, reducing circulation and causing numbness. Tetracycline (10 mg./kgm. twice a day) was administered on days 1-3 post-deprivation to the injured S_s . There was no evidence that this side effect had any confounding influence on the data. All _Ss recuperated and appeared normal following the experiment. Food and water intake and body weight data Figures 9, 10, and 11 illustrate the mean food, water, and body weight measures for each deprivation group over the entire experiment. These data are for only 6 of the 12 S_s, two at each level of deprivation. Tables 14, 15, and 16 in Appendix A are summaries of the variance analyses of these data. The effects of the drug treatment on these measures are determinable from an inspection of the figures and tables. The most important conclusions to be reached are: (a) the drug treatment almost completely 47 Q- Q. a. 3 3 3 O O O cc cr cr o o o cr cc cr X X X o * CVJ CVJ CM r^ \1^ i» • // * .' V • >- < -p c e ■rH 0) Oi X u 0) c •H e -M o u -p X (U Q cr> •H V^ Q ■iS 4J C H 73 O O Q) 3 •H swvao 48 Q. Q- a. Z3 3 3 o o o CC CE cr o o o q: (t • q: X X X o ^ CVJ CVJ c\i N- ^ ^ L » - \ **l ^• +) < i-. < • a: Q. (U 1 1 '-^> > - «> UJ a 1 • ■ 5r h- o Q. 1 0 u V .• • Q V v> ■ CSJ - < ke Duri • V > ffl -P .^'' • - M tr Q. -P c C OJ H E N >..' .' \ o u u 0 > - z 0) Q) y 0 ^ ^^^^ o m X •^JT • U> H IS w y > ■ i • ^ ^. ^ cc o K evj p UJ a t Ul cc 0. 1™" o o c > <0 t c J 00 49 a. 0. Q. => 3 3 o O O cc CE q: (D o o • CC X X X ^ O cvj CVJ "• • \ \ 9 • 1 *, • • . o \ i z - C • • z < in 3 • 4 VAT 10 P -P • /• rC 4J / 1 ^ cn c /; q: •H Q) a. 0) E •• . (M UJ S -H // o )-l >, • t: ^ QC iH . •• • "* ^ r-i \\ UJ 1 •• o 1! 1 3 1 • •• . CS) UJ D^ lii cr •H 0. b ■ I 1 1 1 in ko in N ev» N lO t< ) Oi SlMVHd 50 eliminates eating, and (b) water intake and body weight are also decreased secondary to the drug effect on hunger. These measures all return to normal by the end of the 12 post-deprivation days (readings of these measures were started two days before and continued four days after the sleep cycle recording) . A reduction in circadian variation, similar to that seen in the sleep cycle following drug treatment, is present in the food and water intake data (Tables 7 and 8) . Tolerance does not seem to have developed to the anorexigenic effect of dextro-amphetamine during the five days of treatment . TABLE 7 Mean Percentage of Daily Food Intake Obtained During Dark Hours Days Deprivation level 24-hours 7 2-hours 120 -hours Pre-deprivation ( 1-6) Post-deprivation ( 1-6) (7-12) 63% 69% 7 0% 66 56 56 65 61 58 51 TABLE 8 Mean Percentage of Daily Water Intake Obtained During Dark Hours Days Pre-deprivation ( 1-6) Post-deprivation { 1-6) (7-12) Deprivation level 24-hours 7 2-hours 120-hours 65% 68% 68% 65 57 58 73 64 56 Body weight was lost during the drug treatment. The _Ss were at approximately 92 per cent of pre-deprivation body weight after 24 hours, 87 per cent after 7 2 hours, and 82 per cent after 120 hours. A diurnal rhythm in body weight is present throughout the experiment, and body weight has returned to the pre-deprivation level by the end of the experiment. It is interesting that for the 7 2- and 120-hour groups body weight continues to fall for a day or two following drug withdrawal. Food intake is also relatively low during this period. It is possible that although there is not enough drug remaining in the body to maintain wakefulness there is enough to reduce food intake. The continued low food intake on post-deprivation days 3-10 possibly results from shrinkage of the stomach during deprivation. 52 The inversion of the diurnal effect on body weight during deprivation is an artifact resulting from the procedure having been started in the morning. Each con- secutive weighing was lower than the preceding, and the daytime weighing followed the night weighing on each day. The most to be said about the analyses in Tables 14, 15, and 16 in Appendix A is that these measures seem to be quite variable, and most sources of variances did produce significant effects. An interesting finding is that there are significant individual differences in body weight in spite of no subject difference in food or water intake prior to deprivation. This would suggest that differences in body weight among same aged animals are due to other than intake factors . Another curious finding is that, although sleep time increased above pre-deprivation levels following dextro- amphetamine deprivation, food intake did not. The drug has deprived the _Ss of both of these goal objects, but apparently the S_s compensate, in this particular situation, only for the lost sleep, not for the lost food. This may be due to the aforementioned stomach shrinkage. EXPERIMENT III EEG AND BEHAVIORAL OBSERVATION ON RATS WALKING THE WATER- IMMERSED TREADMILL In some preliminary observations periodic sleep waves were found in the EEG of animals on the treadmill. The rats were seen moving to the front of the wheel to remain stationary as long as 3 or 4 seconds while riding to the rear, followed by walking to the front (taking 2 to 4 seconds) to repeat the process. It appeared that there was good agreement between the EEG synchronization and behavioral motionlessness . This experiment was designed to further study this phenomenon. Method Subjects Three 110-120 -day -old male Long-Evans hooded rats with bipolar EEG electrodes implanted were used (right frontal to right visual) . Food and water were available throughout the experiment. Apparatus This apparatus is the same as the water-immersed treadmill used by Levitt and Webb (1964) . The rats were placed in individual 5.5 by 9.5 inch cubicles, on wheels 53 54 two-thirds submerged in water, which rotated at a constant speed of 2 r.p.m. Food trays were available in each cubicle. The animals remained on these wheels continuously. The total distance covered by an animal was approximately 0.7 mile per 24-hour period. The upper sides of the apparatus were of plexiglass to facilitate behavioral observations. The animals remained on the wheels for 32 hours . Results and Discussion Seven hours of EEG data were collected on each of the three _Ss during their 3 2 hours on the wheel. Figure 12 shows the increase in "sleep" prevalence during the course of the experiment. The increase in sleep during the time on the wheel was statistically significant (p < .05) as was the difference in sleep prevalence between subjects (p < .01) The sleep on the treadmill differed from normal slow wave sleep mainly in the length of each burst. This "micro- sleep" occurred in bursts of only 1 to 4 seconds separated by 2 to 5 seconds of waking activity, while normally, bursts of sleep last for a number of minutes. There was no micro- sleep exhibited on the stopped wheel before the experiment or during the first hour on the moving wheel. It was possible to inspect the EEG records and estimate the amount of micro-sleep obtained by the S^s . By hour 32 _Ss 55 Cr> CM — c ^ "•" u o 5 3 cr o: CVJ Q *\ \ ■ fO 0) • o c I ^"^ \ c o ••- o cr \ \ • • • CNJ _1 _J evale ivati 5 u u • W Q 0^ Ot ^ • / < a^Q \ • / LiJ Q) -'• -•••'( . o CM cr. -Sle mill < -- "^ \ . ^ 2 O 0 Xi U Q) ■H M "•--^ N cn S ^ --V^ a: 3 • \1 -• i • 00 O X rH 1 1 1 It- 1 — (O CVJ 00 ^ o (dnOH U3d) „d33ns-odom „ jo "Nm 56 2 and 3 were micro-sleeping approximately 20 per cent of the time. This is compared to a home cage value of about 65 to 70 per cent of total time asleep for the rats used in Experiment II. As suggested before, this amount of sleep may have more value in reducing compensation than would be expected by the objective amount. Also, it must be recognized that the relationship between normal sleep and micro-sleep has not been established. However, there is evidence that micro-sleep is not equivalent to paradoxical sleep. First, rats have not been observed to enter paradoxical sleep directly, but only via slow wave sleep (Hall, 1963; Swisher, 1962). Since micro-sleep occurs in very short bursts separated by a waking record, it is unlikely that it is similar to paradoxical sleep; the _Ss simply do not have time to pass through slow wave sleep and into paradoxical sleep. Second, Hall (1963) for the rat and Dement (1958) for the cat have found muscle tension to be at its lowest during paradoxical sleep. Both investi- gators reported that whenever the S_ entered paradoxical sleep it collapsed due to the reduced muscle tension. This phenomenon would be inconsistent with the erect posi- tion maintained by the rats on the treadmill during micro- sleep. The data discussed in the preceding paragraph would tend to support a skeptical attitude toward the normative data on paradoxical sleep reported by Siegel and Gordon 57 ( 1965) . These authors reported control levels of para- doxical sleep, for the cat, ranging from 27 to 42 per cent of total sleep. These figures are compared to about 20 per cent in the human (Dement, I960) and approximately 10 per cent reported later in this paper for the rat (Experiment V) . The peculiarity of the Siegel and Gordon study is that during 12 to 14 hours out of each day (at night) the cats were kept awake by being placed on a brick in the middle of a pan of water. The authors report that the cats could not lie down; however, they do not mention having recorded the EEG of these cats on the brick. The evidence on the occurrence of micro-sleep reported in this dissertation suggests that Siegel and Gordon's cats did obtain short bursts of sleep on the brick. However, it is unlikely that any of this sleep was paradoxical sleep, since the reduced muscle tension would cause the cat to fall in the water. Therefore, the normative data on paradoxical sleep as a percentage of total sleep reported by Siegel and Gordon are probably artifactually high as a result of the cats being differentially deprived of para- doxical sleep for 12 to 14 hours a day while on the brick. Figure 13 shows examples of micro-sleep and a behavioral correlation with motionlessness . This behavioral reading was obtained by an observer watching the rat and activating a channel on the EEG record whenever the S 58 EEG KW^iA/fA^ &ehavior -Ur|AJ,y-l|4j/vjw', V\r ^f\^rr' ^jf^A^Y^j'^^ ^v^vVSv-'^'^ ' I ' ' ' '^'^^jW V^^'v^^vvAt^ /A ^^if^iKn^^'f^+t'^ i^^ I I I *V^,kj^A,{g%V^'>^^^v|^;^^V*|W/^J^^^ l| 50 ^v 1 SEC. Figure 13. Micro-Sleep and Behavioral Motionlessness on the Sleep Deprivation Treadmill.* * Right frontal to right visual bipolar electrodes 59 EEG \ ^vw^vVVVM Behavior ."y^yVAVTy., 4^^'''^'^|%l*lfl>»|vjV/'v|-^fj|j- V\J^"l/l/\^^V|^Aiy^vL_/^^ vj.vv|U^LJl^l-.^jUwi!^^ V^i \ /i^ V^AJl,.^Jv>. I I ■^fW^n^4fW\A^ ' 1 ■ K t 11^ jWi ' v•^\^J^^'^^■*^'Hlr^^^Hl^H-•'*t~i^HK Vvw^ > Figure 13. Continued 60 appeared motionless. The £ pressed a switch to activate the behavior channel without observing the EEG record. This correlation appeared to be essentially 100 per cent. There were certain sources of error such as latency of observer's response and the necessity of the S_ being motionless for a short period before ^ could make a decision and activate' the switch. These error sources seemed to account for any deviation between the EEG and behavioral records . It is most interesting to find the rats on the tread- mill able to sleep 1 to 4 seconds, wake up for 2 to 5 seconds to perform a goal directed act, and instantaneously return to sleep. This finding would seem to be of some theoretical interest. First, these results raise a serious question as to the sleep deprivation produced on the water- immersed treadmill (Levitt & Webb, 1964; Licklider & Bunch, 1946; Webb & Agnew, 1962) and on the brick surrounded by water (Siegel & Gordon, 1965). Second, broadly conceived, this micro-sleep phenomenon may be interpreted as an instru- mental response (walking to the front of the wheel) at least partially motivated by the drive for sleep (micro-sleep) . The author recognizes that escape from water is also a motive for treadmill walking and initially the only motive. However, he prefers the interpretation that during the 61 course of the experiment a second motive for micro-sleep also comes into force. The possibility of instrumentally conditioning the sleep response is certainly deserving of further study. Clemente, Sterman, and Wyrwicka (1963), and also the present author (Levitt, 1964) have previously been successful in classically conditioning sleep. EXPERIMENT IV THE EFFECT OF TREADMILL INDUCED SLEEP DEPRIVATION ON THE SLEEP CYCLE (ACTIVITY MEASURE) Although the recording of EEGs on the treadmill showed a sleep-like pattern, it still seemed advisable to study the effect of this deprivation technique on the sleep cycle using the ultrasonic activity method, especially since the _Ss may only experience a sleep state analogous to slow wave sleep on the treadmill. If this were the case, rats on the treadmill would be deprived of paradoxical or "dream" sleep at the same time they were receiving some slow wave sleep. This situation would be similar to the previously discussed "dream" or paradoxical sleep depri- vation studies (Dement, I960; Khazan & Sawyer, 1963; Siegel & Gordon, 1965) . Method Subjects Ten male Long-Evans hooded rats 110-120 days old at the beginning of the experiment were used. Apparatus Sleep cycle recording was by the same ultrasonic activity units used in Experiments I and II. The sleep 62 63 deprivation treadmill was described in Experiment III. The calibration procedure was the same as that used in Experiment II. Design There were five _Ss at each of two deprivation levels (24 or 7 2 hoxors) . Environmental conditions and scoring methods were described in Experiment II. Table 9 illustrates the design of this experiment. TABLE 9 Recording Schedule for the Deprivation Groups in Experiment IV Deprivation Pre-deprivation Deprivation Post-deprivation level 24-hours 3 days 1 day 5 days 7 2 -hours 3 days 3 days 5 days Results and Discussion Figures 14 and 15 illustrate the sleep cycle data from this experiment. Table 17 in Appendix A summarizes the analyses of variance, and Table 10 in the text is an estimate of sleep compensation following treadmill depriva- tion. 64 o 5 > i K a: a. a. lU UJ o o q: c: X X CVJ "C N CSi \ ? iO z o iX. O i H co O •IO CM (-0 I ^ E ol UJ a " UJ 'O ^ o 0 0) u • ■ >1 4J •H C (d 0) -0 g ■H (0 V4 +) 04 d X G u •H g c 0 O •H o ■p * PO fd • rH > (U •H H IM VJ -rH 0 a,E-i (U +J P 0^ 3 QJ 0 H i H rC rH M 0) -rH M (TJ W E-« Q (U -P P • c Tf •H iH g 0) c U (ti 3 0) C7> s •H &< « o o Q o o 0> o o 00 d331S sainNUM 65 h- X < / / / ^-'" / B I I o IT) to O O lO to -IT) 2 O < > a. o co o a. lO -co en -to •z o Q. Ill O - lii (T +> c: (1) Q) +J e =1 •H c M •H (1) g cu X O H o sO C 0 ^ •H O +J * nJ fO • 0) > S ■H ^ m ^1 +J 0 04 >. Q Oi 3 0 -H C nH rtj Ck •iH -H (D e T) (1) 'd 13 rd <-i 0 f« U m -H OJ S-i S-l U -H Cfi (U E-t U 0) 04 -p 0 C7> • c a in •H -H iH E 13 !^ 0) C 0 M m o 3 0) (U cn S M •H 1^ * d331S sainNiiM 66 TABLE 10 Estimated Post-Treadmill Deprivation Compensation 2 4 -hour 7 2 -hour group group 810 810 1 1 810 2,430 Mean pre-deprivation sleep time Days of deprivation Minutes sleep loss Post-deprivation compensation* Day 1 2 Total compensation Per cent compensation 105 63 168 21% 187 126 313 13% * Minutes sleep above the pre-deprivation mean There was a strong circadian rhythm throughout the experiment, but unlike Experiment II there was not a circadian rhythm reduction following treadmill deprivation (Figure 15) . See Figure 5 for a comparison. As a matter of fact, the circadian rhythm on post-deprivation days 3 to 5 was greater than it was pre-deprivation (p < .05) . It was not possible to maintain treadmill deprivation for as long as dextro-amphetamine deprivation, since many _Ss 67 at this age would be expected to reach exhaustion between 7 2 and 120 hours on the wheel (Levitt & Webb, 1964; Webb & Agnew, 1962) . The major conclusions suggested by the results of this experiment are: (a) that sleep time temporarily increased following treadmill deprivation and had returned to normal by the end of the study, and ( b) that there was no significant effect of deprivation level on sleep depri- vation compensation. Both these findings confirm the dextro-amphetamine experiment. Table 10 shows the estimated compensation. It appears to be somewhat less than in Experiment II. The _Ss returned to their normal sleep time range on day 3 post-deprivation, while the S^s in Experiment II did not do this until day 6 or 7 post-deprivation. Also, the total minutes compensation and percentage compensation are smaller in Table 10 than in Table 5. This is especially noticeable for the 24-hour deprivation groups. EXPERIMENT V DEXTRO-AMPHETAMINE OR TREADMILL INDUCED SLEEP DEPRIVATION AND EEG MEASURED SLEEP CYCLE The experiments detailed thus far have produced some interesting and suggestive data on the response of the sleep cycle to sleep deprivation. A question remaining to be answered is whether there is a difference in the response of the two sleep phases (slow wave and paradoxical) to the two deprivation techniques utilized in this paper. In particular, dextro-amphetamine induced sleep deprivation deprives the _S equally of both slow wave and paradoxical sleep. The present experiment will enable us to answer the question of whether the post-deprivation compensation consists of the two sleep phases in their normative proportions or consists predominantly of one or the other sleep phase. Unlike dextro- amphetamine induced sleep deprivation, treadmill induced deprivation seems to differentially deprive _Ss of para- doxical sleep. Although the _Ss also receive less slow wave sleep than normal, the treadmill seems to deprive them of relatively more paradoxical than slow wave sleep. This experiment will enable the description" of the response of the two sleep phases to treadmill deprivation. The information 68 69 reported in this experiment should provide a beginning at answering the question of which phase of sleep is most "needed, " and hopefully also provide part of a foundation for a functional analysis of the sleep phases. This experiment will also serve as a partial replica- tion using the EEG of Experiments II and IV which measured the sleep cycle with the ultrasonic activity units. The data on compensation during the first 24 hours in this experiment can be considered a replication of the compensa- tion findings on day one post-deprivation in Experiments II and IV. Method Subjects Six male Long-Evans hooded rats 110-120 days old at the beginning of the experiment were used. All _Ss had bipolar cortical electrodes implanted. This procedure is the same as that in Experiments I and III. Apparatus The EEG, treadmill, and dextro-amphetamine procedures have been described earlier in this paper. Procedures All six _Ss were placed in the experimental cages 48 hours prior to EEG recording. EEG recording was begun 70 at 8:00 A.M. on day one. Data were not scored until 2:00 P.M. This six-hour period was used as an adaptation procedure. The EEG attachment would occasionally come off the rat and require reapplication. An observer was always in the experimental room monitoring the S_s and EEG equip- ment. The behavioral appearance of _S (sleeping or waking) was periodically noted and marked on the EEG record. These procedures would be expected to disturb the _Ss somewhat and cause them to be awake more than normal. Although this did occur, the change would not seem large enough to effect generalization from these findings . During the control days in the first dextro-amphetamine study, the S_s averaged 68 per cent total sleep. During the Z4 control hours in this study, the _Ss averaged 52 per cent total sleep. Control EEG recordings were made from 2:00 P.M. on day 1 to 2:00 P.M. on day 2 at which time 3 S^s received their initial dextro-amphetamine injection and the other 3 _Ss were put on the treadmill. Deprivation continued for 24 hours until 2:00 P.M. on day 3. Post-deprivation EEG recording began at this time and continued for 24 hours. Each minute of the EEG record was scored waking, para- doxical sleep, or slow wave (normal) sleep. 71 Results and Discussion Figures 16 through 23, Tables 11 and IZ in the text, and Tables 18, 19, and 20 in Appendix A contain summaries and analyses of these data. For purposes of analysis the day was divided into four six-hour periods beginning at 6:00 A.M. Table 18 is a summary of nine analyses of variance performed on these data. Figure 16 illustrates these effects. Dextro-amphetamine deprivation significantly increased the amount of both paradoxical and slow wave sleep and decreased waking as compared with their control values. Treadmill deprivation increased paradoxical sleep without significantly altering the amount of either waking or slow wave sleep. Both these findings (dextro-amphetamine and treadmill) are consistent with those of Experiments II and IV. The bottom half of Table 18 is a summary of three analyses comparing dextro-amphetamine to treadmill depri- vation. The lack of a significant method effect indicates that the two groups did not differ significantly before treatment. The treatment effect on waking and normal sleep is known from the analyses at the top of Table 18 to be completely accounted for by the dextro-amphetamine group. The significant M x T interaction on waking and normal sleep is an expression of the drug, but not the treadmill altering these measures. The lack of a M x T interaction on paradoxical sleep confirms that both deprivation methods increased paradoxical sleep equally. 72 TABLE 11 Sleep Cycle Totals Before and After Deprivation Dextro-amphetamine deprivation Pre Post Treadmill deprivation Pre Post Minutes Waking 7 28 min. Paradoxical sleep 71 Normal sleep 641 1,440 387 min. 653 min. 5 87 min 17 2 86 176 881 701 677 1,440 1 ,440 1 ,440 Per cent of total record Waking 51% 27% 45% 41% Paradoxical sleep 5 12 6 12 Normal sleep 44 61 49 47 Paradoxical sleep as a per cent of total sleep 10 16 11 21 73 TABLE 12 Estimated Post-Deprivation Compensation Dextro-amphetamine Treadmill group group Pre-deprivation 24-hour sleep time Normal sleep Paradoxical sleep Total minutes sleep loss Post-deprivation compensation* Normal sleep Paradoxical sleep Total minutes compensation 641 min. 71 712 240 101 341 7 01 min, 86 7 87 -24 90 66 * Minutes of normal sleep and paradoxical sleep above the pre-deprivation level. Figure 17 shows the deprivation effects as a percentage of control readings for the two deprivation methods, and Table 11 presents pre- and post-deprivation waking, para- doxical, and normal sleep averages for each deprivation method. Table 12 is an attempt to estimate the amount of post-deprivation compensation. Again we see that dextro- amphetamine deprivation increased both normal and para- doxical sleep and decreased waking; however, the major 74 Q < z o §? K a. a.iu I119 '- m o o. I I i < > oc Q. UJ o CD z < UJ a. < s > O CL »- ^ X UJ o -> 1 r 1 r- O o o O o o 10 CM — '. a ■5> ^ - < 2(0 STi q; i «0 • UJ s. is h- rH S q: rH T3 0 **• z <0 g •• (ti T3 (D • 0 0) 0 a < z ^^ >i (U (0 1 xtro-Amphetamine or T privation and Sleep C king, Paradoxical Sle rmal Sleep. , QJ OJ ftJ 0 ■ 2 Q Q ^ a ^i • S. < S. to • ai ■«; <-{ '^ 2 QJ (0 1 UJ u s 3 §0: z <0 H •H s § ■ 0 < z «> » SBIONIIM 75 z s o >5 a: a. a. uj u o ?A u 0> or o a 0. I 5 > UJ QC CC Q. I- UJ o a. UJ LU -J CO _J < o X o o < a: Ul 1: 2 2 > o "^ q: uj X UJ 1 5 ■0 , < 2 0 S ■0 fi. Z U) 1 1 c s 0 0 Q. z U> CI S 0 0 < Z u> 1 UJ \ -T 1 1 i 9 1 — r- o o o o N 10 10 — - < 0- s c S § a; Z (fi 2 § • o < Z UJ (1) C •H +J c o u o •H Cm sainNiw 76 ^1 5> >S te a. ill C9 a. & II '. 2 •X3 i2 2 -6 '^ i ^^ O ^ q: lu X UJ o 2 2 § o: Z (O 2 o UJ o o 10 o o M O O -a c •H +> C O O r-i u in ■w S3inNm 77 m w O. kJ a 0 \ 04 H Hi CO g H i «D UJ 00 m s ♦ z 1- < lO a: M leep-Waking age Change s . CO -P 0) C 3 C 0) ^ ♦ ^ 0 U n3 o •H »^ > ^ fti a* .H m !i > 0 •H nj M M oe >^ 4J Post-Dep Cycle as from Con T- O O "T- O o M M QC Ul GO < -I o 0) 3 •H Cm lOUiNOO «I0 lN33d3d 78 effect is on paradoxical sleep which increases from 10 to 16 per cent of total sleep. Treadmill deprivation strongly increased paradoxical sleep, and this increase was allowed for by small but nonsignificant decreases in both waking and normal sleep. Paradoxical sleep increased from 11 to 21 per cent of total sleep after treadmill deprivation. The increases in paradoxical sleep produced by dextro-amphetamine or treadmill deprivation were not statistically different. An attempt was made to further analyze the change in paradoxical sleep following deprivation. Figure 18 shows the mean sleep epoch length before and after depri- vation. Table 19 is an analysis of variance which con- firmed that the sleep epochs were longer after deprivation than on the control day. A sleep epoch is defined as four or more consecutive minutes of sleep (either slow wave or paradoxical) . In order for a sleep epoch to be terminated, four consecutive minutes of waking must interrupt the epoch. It is known from numerous studies of sleep in humans that REM sleep tends to occur in the second half of a night's sleep (Aserinsky & Kleitman, 1953; Dement & Kleitman, 1957a) . This relationship has not heretofore been demon- strated in rats, but, if it existed, an increase in length of sleep epoch might be expected to produce increased para- doxical sleep as a nonspecific effect. 79 — Pre-Deprlvotion •-Po8t-Depriva4 ton u I- Z 80- 60- 40 20- 1 1 1 1 6 A.M. Noon- 6 P.M. Mid.- • Noon 6P. M. -Mid. 6A.M. TIME Figure 18. Length of Sleep Epochs 2.8 S 2.4 1 I- Z ^ 2.0 H 1.6- — I 1 1 i 1 0^-' '^-^-, 1 3 ! ! 1 ' 0-iO 11-30 31-60 61-100 101-180 MINUTES INTO SLEEP EPOCH Figure 21, Percentage of Total Sleep Time Spent in Paradoxical Sleep. 82 Pre-DeprIvo?lon Posf-DeprlvotJon CO UJ I 5- I 3- I I- 9- 1 1 1 r- 6A,M. Noon- 6P.M. Mid. -Noon 6P. M. -Mid. 6A. C TIME Figure 22. Minutes into Sleep Epoch When First Minute of Paradoxical Sleep Occurs. CO oc Ul o < > o UJ o 111 UJ O Q. X hi \0' ^. *-" N •" S 6- \ / /\ \ 2- 2v ^•y \ ^ 0- \^ \ 1> -2- > 1 r- 0-10 11-30 31-60 61-100 101-180 MINUTES INTO SLEEP EPOCH Figure 23. Difference Between Observed and Expected Awakenings from Para- doxical Sleep. 1963; Swisher, 1962). This was not confirmed in Experiment I, since activity during paradoxical and slow wave sleep as measured by ultrasonic activity errors was about equal. However, the hypothesis that _Ss awoke more frequently from paradoxical than slow wave sleep was tested and con- 2 firmed (x =60.2, df=5, p< .001) . If the rats awoke from sleep epochs ten times during 100 minutes of sleep and paradoxical sleep amounted to 10 per cent of sleeping time, then we would predict one awakening from paradoxical sleep. Figure 23 presents these data. The S_s awoke significantly more frequently from paradoxical sleep than would be expected. This finding perhaps suggests a disturbing influence (dreams?) during this stage of sleep. SUMMARY AND CONCLUSIONS Experiment I The Development of an Ultrasonic Activity Device to Measure Sleep and Waking in the Rat This experiment established the ultrasonic activity system as a useful and reliable means of measuring the sleep cycle. These units are especially valuable for long term recordings for which the EEG is impractical. It is realized that it is still necessary to refer to the EEG periodically to recheck the EEG-activity correlation and also in order to differentiate sleep stages. The ultrasonic activity unit can introduce new experimental possibilities into sleep research. With these units it should be possible to continuously monitor the sleep-waking cycle of small mammals for months or longer. The disadvantages of the EEG, which are eliminated by ultrasonic activity recording, include: (a) large expense in time and money, (b) the necessity of surgically implanting electrodes, (c) the expense and difficulty of reading and interpreting EEG records, and ( d) the necessity for the animal to trail electrode wires, which probably disrupt the naturalness of the response under study. The major disadvantage of ultrasonic activity recording — not 84 85 being able to differentiate sleep phases — has already been mentioned. The interesting finding of no difference between the percentage of high voltage slow sleep minutes and LVFS minutes, which produce errors, would lead to the conclusion that the S_s were equally active during these two sleep stages. Experiment II The Effect of Dextro-Amphetamine Induced Sleep Deprivation on the Sleep Cycle ( Activity Measure) The stability of the sleep cycle in this experiment and also in Experiments IV and V is quite rewarding. It must be realized that these are the first explorations utilizing the techniques of ultrasonic activity and pro- longed EEG recording. It is expected that future experi- ments will use longer recording periods and also that, as the ^s become more familiar with the equipment, an even more stable baseline will be found. This consideration is important, since the magnitude of experimental effect required to produce statistical dependability is partially determined by the stability of the baseline measure. The fact that results of both statistical and psychological import were found in all the studies reported here suggests the systems (ultrasonic activity and EEG) are sufficiently reliable for variables of the magnitude used. 86 The experiments reported here also have allowed the description of the parameters of sleep behavior in the rat. These are the first sleep studies in the rat of sufficient length to allow a description of the normal sleep cycle (see especially the normative sleep cycle data from Experiment II, and also the pre-deprivation measures from Experiment V shown in Table 11 and Figures 16 to 23) . These data apply only to a limited subject population but are, at least, a beginning at a description of rat sleep. The dextro-amphetamine technique was successful in almost completely eliminating sleep during the deprivation period. The two major findings of this procedure are: (a) that the drug induced sleep deprivation resulted in a temporary compensatory increase in sleep time following drug withdrawal, and (b) that increasing deprivation from 24 to 7 2 to 120 hours did not produce any significant change in the amount of compensatory sleep. The most exciting conclusion suggested by these data is that increased sleep deprivation over 24 hours up to 120 hours does not result in an increased sleep need over that present in the 24-hour sleep deprivation group. Two possible alternatives to this conclusion have been discussed earlier. First, although the amount of sleep during deprivation was small compared to the normal level, sleep was present. It may be that sleep during a heightened need is "more valuable" in 87 relieving the deficit than under conditions of normal drive. The data from Experiments III and V would seem to confirm this hypothesis, since in Experiment III the _Ss obtained sleep in smaller than normal amounts on the treadmill, and in Experiment V this amount of sleep was sufficient to eliminate the need for post-deprivation slow wave sleep compensation. Further experiments which (a) are more successful in completely eliminating sleep, and (b) study the effect of small amounts of sleep inserted at various times during deprivation, will help to answer this question. Also, the dextro-amphetamine anorexigenia may interact with the sleep need and change the shape of the recovery function. Stomach loading during deprivation may control for this effect. However, the author prefers the interpretation that the lack of increased compensatory sleep with increased sleep deprivation from 1 to 5 days reflects the relationship between deprivation and need. This finding may be very significant if confirmed. It is conceivable that similar findings would be found in other species; of particular interest are the possibilities and implications for humans in acute behavioral requirement situations . There was no cultural restraint on the sleeping time of the rats in this study. We can assume that they received all of the additional sleep they required. The amount of 88 compensatory sleep should reflect the biological deficit and sleep requirement produced by prolonged dextro- amphetamine induced sleep deprivation. Dextro-amphetamine is a sleep depriver that requires no effort to stay awake by the subject; thus, perhaps leaving _S free to perform tasks that an individual intent on remaining awake could not perform. These possible effects may have important applications in behavioral situations such as may be found in military and aerospace programs . One conceivable fault of the dextro-amphetamine technique is that sleep loss effects are compounded by muscle fatigue, but it seems that all methods of producing sleep deprivation require movement and work on the part of the subject. At present it is not possible to keep an inactive S_ awake. Kleitman (1963) found that the only way he could keep human _Ss awake was to have them engage in some sort of muscular activity. Whether the beneficial effects of dextro-amphetamine outweigh the toxic ones in particular behavioral situations remains an open question for further study. Further study of behavioral capacity during and following dextro-amphetamine administration in doses sufficient to maintain prolonged wakefulness in animals, and particularly in humans, would be of con- siderable importance. Of at least peripheral interest is 89 a review article by Weiss and Laties ( 1962) , who have examined the effects of dextro-amphetamine on performance, concluding that physical endurance, capacity, and motor coordination are enhanced. Dextro-amphetamine seems to hasten conditioning, to improve discrimination learning in sleepy _S s , and increase the rate of motor learning. Dextro-amphetamine apparently does not lead to improved intellectual performance except when normal functioning is degraded by fatigue or boredom. Weiss and Laties conclude that there is no convincing evidence that a psychological or physiological price is paid for the enhanced performance. The curious finding that sleep time does not increase or increases very little during the daylight but that large amounts of compensation occur at night following sleep deprivation is of some interest (see Figures 6 and 14) . The suggestion that the rat sleeps maximally during the day, in the same sense that a human sleeping in bed from midnight to 7:00 A.M. sleeps maximally, should be tested. Experiment III EEG and Behavioral Observation on Rats Walking the Water-Immersed Treadmill The finding of micro-sleep in rats walking the sleep- deprivation treadmill is of considerable interest. This 90 finding effects the interpretation of a number of experi- ments which have studied the effects of sleep deprivation produced by a water -immersed treadmill or similar apparatus on later behavior. These _Ss were not completely deprived of sleep, to say the least. This experiment is also of interest, since the micro-sleep phenomenon may be con- sidered to have the properties of an instrumentally condi- tioned response motivated by the sleep need. Experiment IV The Effect of Treadmill Induced Sleep Deprivation on the Sleep Cycle ( Activity Measure) The results of this experiment suggest that, although rats do experience a "sleep-like" state on the treadmill, some type of deprivation condition is produced. The major findings confirm the dextro-amphetamine experiment: (a) deprivation did result in increased sleep, and (b) increas- ing the deprivation level from 24 to 7 2 hours did not significantly increase the amount of compensatory sleep- This finding would suggest that the similar observation in Experiment II was not due to food deprivation factors. However, these S_s also obtained larger amounts of sleep (micro-sleep) during increasing deprivation (see Figure 12), and this problem has not been resolved. 91 Experiment V pextro-Amphetamine or Treadmill Induced Sleep Deprivation and EEG Measured Sleep Cycle The normative data produced by this experiment have been discussed above. The most interesting finding is that dextro-amphetamine deprivation results in a compensatory increase in both slow wave and paradoxical sleep (confirming Experiment II), while treadmill deprivation produces a compensatory increase only in paradoxical sleep (suggesting that the compensation in Experiment IV was only for paradoxical sleep) • The tread- mill results confirm the finding of micro-sleep in Experi- ment III and suggest that this phenomenon is analogous to slow' wave sleep. However, dextro-amphetamine deprivation also increased paradoxical sleep more than slow wave sleep. This finding that paradoxical sleep occupies a higher percentage of total sleep suggests a function in speci- fically remedying a high sleep need state. Certain specific psychological and/or physiological activities may occur during paradoxical, but not slow wave sleep. These acti- vities apparently have a high need priority above those occurring during slow wave sleep. The nature of these activities is not known, although the psychological functions may be related to the dream state. This finding of a high priority for paradoxical sleep compensation following deprivation has been confirmed by 92 Svorad for the rat (Webb, personal communication) and Ferguson and Dement (1965) for the cat. Berger and Oswald (1962) and Williams, _et _al. (1963) have also con- firmed these findings in the human. However, the human studies have found a stage 4 compensation to occur before REM sleep can increase. Since stages within slow wave sleep have not been differentiated in the rat, these studies are not directly comparable. These studies would seem to indicate a high "need" for both paradoxical and stage 4 sleep. These results, showing specific compensatory changes in stage 4 and REM sleep to follow sleep deprivation, are in conflict with Dement ' s (1965) hypothesis that physiological variations within NREM sleep do not warrant further subdivision. The results of Berger and Oswald (I962) and Williams, ejt a_l. (1963) suggest a functional differentiation of stages within NREM sleep, since stage 4 responds differently than other NREM sleep to deprivation. A further analysis of the paradoxical sleep effect indicated a specific activation of this state, which was similar for both dextro-amphetamine and treadmill depri- vation procedures. Following deprivation paradoxical sleep occupied a significantly higher percentage of total sleep, and bursts of paradoxical sleep occurred more fre- quently during a sleep epoch. Also, a nonsignificant increase in the length of each burst and an earlier 93 appearance of the first paradoxical sleep burst (also not statistically significant) confirm that sleep deprivation specifically activates paradoxical sleep. The finding that _S_s awoke significantly more fre- quently from paradoxical than from slow wave sleep than would be expected suggests the occurrence of a disruptive phenomenon (perceptual dreams?) during paradoxical sleep. Rechtschaf fen and Maron ( 1964) have reported that dextro-amphetamine administered to human S_s prior to sleep resulted in a decrease in the percentage of sleep time spent in REM periods as compared with control nights. A compensatory increase in percentage REM followed 3 or 4 nights of this partial REM deprivation. These findings of Rechtschaf fen and Maron are consistent with the results of dextro-amphetamine sleep deprivation reported in this dissertation. Rechtschaf fen and Maron state that, "This REM reduction indicates that relative to other sleep stages, REMPS do not represent states of arousal in the sense in which arousal is used to describe waking behavior" (1964, p. 444) . However, Rossi (1963) and Oswald, Berger, Jaramillo, Keddie, Olley, and Plunkett (1963) have shown that barbi- turates also suppress REM sleep, indicating that neither are REMPs states of nonarousal relative to other sleep states. These results contribute to the conclusion that 94 REM or paradoxical sleep represents a neurophysiologically and psychologically unique stage of sleep not classifiable along a continuum of light to deep sleep (Dement, 1965; Jouvet, I960) . APPENDICES o H X > H P t^ S O M Oj Ul ^ I^ ro o >1 o Dh 0) O iH CO 'C C O -H ■P > •H D^ Q) P T3 Q) O :3 Ti c H c •H e ■p I o u 0) Q 00 1 1 ITI c W 0 >i •rH ITJ -P Ti fO .,_^ > •H u a^ 1 fd TJ o p ^ > I ■H rH CD >i I T5 0)^ ^^ A4 0) O o O LTl iH o o o I I o o I I I I IT) O IT) O O O I I g ,^ -P >1 rC S-l c ISi fd -p ■H o 'd 0) fd U •n u U) cQ !-l >^ X 13 ■H fO p p co|u|P|co en u c 0 •H •P fd > •H 1 M p Oh U) (1) 0 1 0^ (U 00 H 1 C Qjin 0 •H M* m -P 1 >. (d iH fd > 13 •H m Sh >i • Qk fd M 0) P >T! 0) o M 3 O o I o o I o I I c 0 -H •p nJ > •H 1 !h P D4 en (U O 13 04 rH H <-{ 1 o O o i fd H fd > 13 •H m H >i • Cli (d CO 0) P >13 I I w ,c OJ +J rH >i rC c u 0 p •H C c p fd 0) fd -H e > 13 -p •H fd fd n u 0) Oi u u (D -H u X POOP X X X X Eh|P1U|B Eh P E-i m •H 13 >i •P •H > P o (d c o fd u -p 13 0) w fd s: 96 97 0) ri<; (tf 4J C H -d o 0 Pm •a Q) T! 3 C c ni •H +> C G 0 0 •M o '^ -P iH fU 1 > w •H < (J S-l X § Q) H Eh P Q a (U W C Oi -H Ri H < rtJ +> 1 O Q I c o •H -p — . > •rH ft 0) tn -p x> CO «— o O •H -P > MD •H I ft I -p m O T3 C O ■H 4-1 — > I i-l ft w 0) >i I 13 04 o s-l o 1 o o I o I I I-l u^ o o o o o o I I ,c -p >1 rc; s-l c w fd +j -H U 13 Q) fd •r-i 0 en ,Q ^ >i 3 -H rd U P P colu|Plco w u a o •H +J fd > 1 •H +J S-l to ft O (U ft I 00 Q) iH S-l I C ftr- O •H vO to +J I >i fd r-l fd > to s-l >1 • ft fd to Q) P > TJ O LTi O 1 o o o in 1 o C O -H +> (d > ■rH I S-l 4-1 ft to Q) O -d ft 1 Q) vO ^1 1 C ftrH 0 iH rH iH r-l •H .H iH rH rH O O O O vO to -P O O O O O O O 1 o 1 >, fd O O O 1 O • • • • Days 1 vs . da depriv • • • • I o (0 a) g >^ Q) 4J rH >1 ^ C M 0 4J -rH C C -P fd CD fd -H (U E > ^ u 4J -H fd s-l fd sh o 3 (D ft 5^ 0 U Q) -ri C/3 BIPIUI o X P U U P X X X X en Eh P Eh 98 O X rtJ +> c H M 0) +J (d ^ Ti 0) -a 3 d C ni •H +) G C 0 O •H O in -P 1 r-\ > W •rH < H^l U X! § H EH Q P ;zi O w G di •H a e 1 1 o u +» rH •rH 1 J-l r- ft 0) w T3 >i 1 m 4-1 T! 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Q (0 u •n u CO rQ Vh >i X 3 •H fC P Q X X co|U|Qlw W U o u o I I I 0 •H -P fd > ■H 1 U -P 04 cn Q) 0 13 O4 I 0 0 iH 0 CU vO 0000 1 U 1 c « • 1 • 04^ 0 -H no cn -P 1 >i re tH a > ^ •H cn M >. • 0, ra cn 0) P >'d I I m r^ (U -P rH >i ,C C Sh 0 -p •H q; c -P fO (1) m -H E > 13 ■P ■H rd fd U U 0) O4 >H Sh Q) -H u X POOP X X X X HIPIOIEH B P Eh 100 •3«- Q) .H U >i U a 1 H H D^ < J (U X § Q H Eh 'd Q in •-H 1 ^^ m a 0) M Ti >i 1 rt) 4-> TJ M ■s.^^ 0 Pn C o •H -P ITJ , , > ro •H 1 M rH D^ Q) CO ^ >1 1 (TJ -M T) W ^^ 0 ^ ii; o •H -P , . rtJ ro > 1 •H H ^1 a, M Q) >, -o m 1 'd >i rC M c w nJ +J ■H o ^ QJ m o •i—i u cn ,Q M >i X 0 ■H fO Q Q X X wlulQlw w u c: o •H 4J n} > •H 1 ^ +> a M (U 0 ■d Oh 1 0) in u 1 c: iH Dhpo 0 o in ■H 1 1 o 1 o ro to 4J • • 1 >. nj rH nj > TS -H en ^) >i • Q< nJ w (U Q > -d (1) u u 3 O CO I I C 0 -H ■p (« > •H 1 U -P A m a) 0 ^d D4 1 (1) fvj u 1 c: a,rH 0 H H H •rH rH rH O o o in ro, W -P o o O 1 o o o ] >l(^ o 1 o • • • ■ Days 2 vs . da depriv • • -p c 0) e +j rri a) S -P >i I I I o 'd m Q u u Q u u X X X X 03 -p •H c 13 >1 -p •rH > ■rH -p U m o •rH C o w m 5h 4J rQ -d en ro (1) S EHlQlOjEH Eh Q Eh 101 >i U a, (1) Q) .H W T5 C fd c o -H 4-> tT5 ■o > 0) •H ^ U a a •H QJ +> Q c 0 -a u 00 0) 1 rH U =3 M 'd < a C X § H H Eh nH Q H •H H £ 04 13 % 0) 5-1 Eh O Q) C •H S nJ +1 QJ & I o ■p X 0) Q (1) c e 4-) 0) ,c o^ g m I o u •p X (U Q (0 E o 0) 0) u o fd tn C •H m IS (1) o S-l 13 o CO rH in tn o o o o o I I O lO nH O O O -P >1 •H fd u M U (1) -H Q10|Q e 13 (d 0) Eh in I I o o o O O I O I o C O •H -P fd > e +) fd 13 •H (d M O D^ 5-1 (1) -r-l Q|U| o X 0) U fd e o o o ■H p td > •H Sh C4 Q) 13 13 fd Q) -P 13 C fd Q) c e fd -p Q) fd I O u p X 1 c fd •rH 13 fd u u u Eh U U Eh X X X X m w >i 13 Q) ca fd Q) S|Eh|U|S 2 Eh S 102 APPENDIX A - Continued TABLE 19 Mean Length of Sleep Epoch as a Function of Sleep Deprivation Source raeuilOU " treatment .001 ^ircadian rhythm .01 M X T - M X C - T X C - M X T X C - 103 APPENDIX A - Continued TABLE 20 Length, Frequency, and Percentage of Paradoxical Sleep as a Function of Sleep Deprivation Source Length of paradoxical sleep bursts Frequency of paradoxical sleep bursts Per cent of total sleep time in para- doxical sleep Method ^Length _Treatment M X L M X T L X T M x T X L .05 .001 .05 .001 X H § H H H W X w Pi o Cm < * H > H E-i O H o Eh ^^ :3 O H > H Q CU w < H O H H a O &H w CM I o Pi E-i X M Q CM 04 d o u en I o o 00 04 O I vO in O. o I (M iH ro in ro in ro 00 00 -^ O in in ■^ 00 rj< ro rH o rj rH in Tf ro rH in in o ro in o ■* fO in r~- ro o in m CO ro in ro r^ r- ■^i* rO ro 00 o vO ro ^ ro in r^ (M M in ro H 00 in a^ ■^ CO in vO r^ ro •r)< ro in t-\ oo o in ro in T}< r~- 00 w -p >1 CP ^ n3 •H fS Ti J|Q| +J .H o 0 Q> u •n -p rH ,0 c 3 0 CO u ro ro ro ro in in ro rH C^ ro O vO o ro in ro in T}< 00 ^ ■^ ro 00 00 in sO -t ro ro 00 o 00 in ro in o in ro <-\ o vO in •^ ro ro fO in ro 00 ro ro O ro ro in ro o in r^ in in CO •* 00 ro 00 ■^ ro ro o ro 00 T}< ro ro ro in '* ro in rH o ro O ro O ro ■"^ OJ cH H >H 00 't ro o r^j ro sO ^ ro ro ro ro iH in o 00 Tf ro vO ro ■^ ro ro o •^ ro in ro H •vO iH T}< OJ r~ 00 ■5j< ro •* ro ro 00 ro ro CO o in 00 t^ •^ ro J Q ^^ a *^ Q o •H u en c -H fd o o U 0) -P •H 6 I o o S-l 0) o. 0) rH w H-l O Q) +J * 104 105 cu 3 13 o 0) u 0 Cri a •H • •P 5-1 CI rC o 1 o rj r- X H P (M a, :i o u en S-i I o (M O 00 ^0 in o I ro ro (M 4J U (U -t— I W vO ro fNj ro in ro O in CO in ro ro ro O .H vO ro in in o rH in ro o in H ro o in in cr> in 00 vO 00 00 o in r^ ^ ■* 00 00 ro ro in H O in •* ro in ro r- o ■ in •rt< ro rH rH ro ro ro in ro CO o 00 ro CO -^ ro in in ro in 't Tt< rH O vO in ^ ro ^O 00 vO vO o rH 00 ro (M •<4< ro in 00 rH ro .■<;t< ro H rj ro t^ ■^ ro rH O ro 00 in iH ■<* ro rH ^t^ o 00 ■^ ro iH in ro ro Tf ro 00 vO rH ro ■>^ ro sO iH 00 iH ■ •H u ^ I 4-> CO O vO O in -^ 00 00 in ro 00 vO in rf* r^ in in in rH ro ro o in rt< rH 00 00 ro ro Tj< 00 m ■^ CO in in in -"ti r- ro r-H in in 00 ro iH in in 00 ro m ro iH 00 in Tj< ro ro 00 r- •^ ro TjH ro in ■* ro -^ in ro O rH r-i 00 rt< ro o in in T}< in ro in ro ^D O in in '^ 00 o^ ro ■ a> m O Ui Q) -P C * 106 107 (U c ■H +1 c o u u X H Q W O I 00 vO O U S-l I (M in ■^ rO ro 0 •H +J n3 -> > . •H +J S-l C a, 0 +J Q) o u rd ^ Q) 1 •t— > 4J CO fit CO >i J3 0 m CO O* 'O 00 o o 00 O 00 CO ro rO CO ro O ■^ en M^ 00 in ro o m m o in •^ o c\j ■* CO in r-{ 00 in ■<^ CO o 00 O rH in CO 00 vD 00 o Tt* rg r- in 00 r- 00 rH in •* 00 o (M in in -"i^ •* CO ro so in CO 00 OJ ^ CO r^ 00 O CO ■>*' CO CO in in CO in o in fM o o vO rH in CO sO o in CO CO [^ in CO CO o CO 00 in CO in o r^ 00 Tt< CO in o iH Tf in CO o o in CO s£) in in H Tt< CO H r- (M O in ^ h:1 Q ^^ Q ^^ Q CO in APPENDIX D ORIGINAL DATA FOR EXPERIMENT V DEXTRO-AMPHETAMINE OR TREADMILL DEPRIVATION AND EEC* Subject Dextro-amphetamine 12 3 Treadmill 4 5 6 Time Pre-deprivation 6:00 A.M. - noon W L S 292 240 243 194 217 264 3 13 16 7 21 4 65 107 101 159 122 92 noon - 6:00 P.M. w 190 68 150 140 91 65 L 30 11 17 26 35 31 S 140 281 193 194 234 264 6:00 P.M. - midnight W 113 107 17 9 108 79 109 L 21 8 33 18 43 32 S ■ 226 245 148 234 238 219 midnight - 6:00 A.M. W 194 173 236 202 278 214 L 30 15 16 13 13 15 S 136 17 2 108 145 69 131 * Minutes of waking, IiVFS , or slow wave _sleep per 360-minute observation period; lights on 9:00 A.M. to 9:00 P.M. 108 109 APPENDIX D - Continued Subject Dextro-amphetamine 12 3 Treadmill 4 5 Time Post-deprivation 6:00 A.M. - noon W L S 66 102 22 129 228 189 57 25 52 50 22 15 237 233 286 181 110 156 noon - 6:00 P.M. w 62 88 55 113 83 68 L 44 35 44 61 68 46 S 254 237 261 186 209 246 00 P.M. - midnight W 115 127 104 159 98 156 L 63 32 59 64 72 46 S 182 201 197 137 190 158 midnight - 6:00 A.M. W L S 117 101 203 198 182 157 55 27 22 28 25 32 188 232 135 134 153 171 REFERENCES Agnew, H. W. , Jr., Webb, W. B., & Williams, R. L. The effects of stage four deprivation. EEG clin. ■' ■» Neurophysiol. . 1964, J/T., 68-70. Aserinsky, E. & Kleitman, N. Regularly occurring periods of eye motility, and concomitant phenomena during sleep. Science, 1953, 118, 273-274. Beckman, H. 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J_. exp. Psychol. , 1957, 53, 162-166. Webb, W, B. Personal communication. ^ Webb, W. B. & Agnew, H. W, , Jr. Sleep deprivation, age, and exhaustion time in the rat. Science, 1962, 136, 1122. ^ Webb, W. B. & Agnew, H. W. , Jr. The results of continued partial sleep deprivation. Paper read at Association for the Psychophysiological Study of Sleep, Washington, D. C, March, 1965. =«— Weiss, B. & Laties, V. G. Enhancement of human performance by caffeine and the amphetamines. Pharmacol. Rev. , 1962, 2A' 1-36. , Williams, H. L. , Hammack, J- T., Daly, R. L., Dement, W. C, & Lubin, A. Response to auditory stimulation, sleep loss and the EEG stages of sleep. EEG clin. Neurophys iol . , 1963, _16, 269-279. Williams, H. L. , Lubin, A., & Goodnow, J. J. Impaired performance with acute sleep loss. Psychol . Monographs, 1959, 73, 26. BIOGRAPHICAL SKETCH Robert Alan Levitt was born in Baltimore, Maryland, on November 9, 1938. His family moved to Miami, Florida, when he was a child. He attended Miami Senior High School. Upon graduating from high school he enlisted for six months' active duty in the U. S. Army. After his active duty, he spent one year at the University of Miami, after which he transferred to the University of Florida, receiving the B.S. degree (major in pharmacy) in June, 1961. In January, 1962, he re-entered the University of Florida for graduate studies in psychology, and received the degree of Master of Science in June, 1963. From September, 1963, until the present time he has pursued his work toward the degree of Doctor of Philosophy. During this period, he held a NASA Pre-doctoral Traineeship. 114 This dissertation was prepared under the direction of the chairman of the candidate's supervisory committee and has been approved by all members of that committee. It was submitted to the Dean of the College of Arts and Sciences and to the Graduate Council, and was approved as partial fulfillment of the requirements for the degree of Doctor of Philosophy. August 14, 1965 ^St^?^-*-"'''^ ^ L^-r>C Dean, College of Arts and Sciences airman t