James Hawkins

REM sleep deprivation increases aggressiveness in male rats

Abstract As a test of the hypothesis that REM deprivation increases aggressiveness in rats, the effects of two and four days of REM deprivation were measured on the frequency and latency with which male rats attack mice. The results showed that REM deprivation increased the frequency of attacks, the muricide rate, and the latency to first attack in a “dose-related” fashion. To a degree these behaviors persisted through a 21-day recovery period.

Pain Thresholds in Rats during Recovery from Rem Sleep Deprivation

Using 30 Sprague-Dawley female rats, threshold to pain was measured over the course of recovery from REM sleep deprivation. Relative to the untreated controls and to their own pretreatment thresholds, the REM-deprived animals showed significantly reduced pain thresholds which were still evident 96 hours after the termination of the REM deprivation. Possible implications of these data for research with analgesic drugs were noted.

Emotionality and REMD: A rat swimming model

Abstract The drugs used in treating people who suffer depressive illness typically reduce REM sleep. We report a non-pharmacological validation of a screening test which is selectively sensitive to those drugs. This indicates that REMD, not other drug effects, is operative. We define a measure of emotionality, which is sensitive to REM status, in that context. Emotional defecation increases during REM rebound providing a model outcome which parallels clinical findings.

Type A behavior and normal habitual sleep duration

The responses of 361 college students to the Jenkins Activity Survey and a self-report sleep questionnaire were used to demonstrate an inverse relationship between normal habitual sleep duration and level of Type A behavior. The possibility that patterns of sleep may be implicated in the development of Type A behavior in some individuals was considered.

Handedness and sleep duration.

The differences in habitual sleep duration and absolute deviations in habitual sleep duration from the normative mean between 60 left-, 36 mixed- and 125 right-handed college students were tested. It was found that mixed-handers tend to sleep less and as a group show significantly greater deviations in habitual sleep durations than either left- or right-handers. The heuristic value of this relationship for future research was discussed briefly.

Sleep Satisfaction and Intentional Self-Awakening: An Alternative Protocol for Self-Report Data

We have reported that sleep satisfaction provides an effective research variable for use with large groups. It affects self-report measures of waking behavior, time spent in bed, and both spontaneous and intentional awakenings from sleep. Here, we report that with a counterbalanced design and self-awakening requirements meant to be more difficult for the subjects to attain, systematic differences were, again, found for the sleep-satisfaction groups. Self-reported sleep satisfaction is an heritable behavior. The genetic and environmental implications are discussed.

Rat strain comparisons on drug and sleep sensitive behaviors

Rat swimming behaviors have been productive in both sleep research and neuropharmacology. In this report, both of these areas are addressed in the context of inbred strain effects. Thirty-two rats from three stocks were tested in a seven day, repeated measures design. Each rat swam for 5 min each day in shallow 25 degrees C water. There were significant differences between inbred stocks on two measures which can be related to both REM sleep deprivation and adrenergic drug effects. Nonsignificant strain differences were found on two other behaviors which also lack significance under REM sleep deprivation and atropine sulfate treatments. It is concluded that there may be differential stress affecting the treatment-sensitive and the change-resistant behaviors.

REM sleep deprivation and food competition in male rats

Abstract As a test of the hypothesis that REM deprivation lowers the threshold for “motivational” behaviors, 17 male rats that had been REM deprived were tested against 17 non-deprived male rats in three series of food competition tests, i.e., an immediate, a 3 hr, and a 48 hr series of posttreatment tests. The results provide support for the hypothesis that REM deprivation generally activates “motivational” behaviors, in that the REM deprived animals won more frequently as had been predicted. However, the response gradients of the two groups over the course of the postteatment test series did not conform to prediction. These data are discussed together with the results of other studies which suggest that perhaps the list of behaviors which have been subsumed under the category—“motivational behaviors” is too broad to be of real scientific value.

Test anxiety levels of short and long sleeping college students.

To clarify the interpretation of a difference in anxiety level that Hicks and Pellegrini (1977) had reported as being incongruent with Hartmanns (1973) description of the personalities of short and long sleepers, groups of 20 short- and long-sleeping college students were tested using a battery of anxiety tests which featured two test anxiety scales. Congruent with Hartmanns hypothesis that short sleepers value work as a defense, our short sleepers showed significantly higher levels of test anxiety on both scales. These data were considered against Hicks and Pellegrinis earlier results with the conclusion that those data actually support Hartmanns conclusions.

Swimming immobility and rat REM deprivation: A pilot study on time-delay effects

This paper helps to solve a practical problem in the ongoing sequential validation of an animal model concerned with emotionality and adaptation. The performance measure used involves the swimming activity level of rats on a series of trials. Earlier work with a different (open-field) measure had indicated that heightened activity might occur simply as a result of the REM-deprivation method that we use. A problem in evaluating that work, in the context of our own, is that it involves a very long time-delay interval. Our model is sufficiently complex to make that interval impractical for our use. Here we report a small sample evaluation that documents the effect seen earlier, but which also makes possible a more convenient time delay for future work.