John M. Taub

Effects of habitual variations in napping on psychomotor performance, memory and subjective states.

Effects of habitual variations in napping on psychomotor performance, short-term memory and subjective states were investigated. The subjects were 32 healthy male university students who napped twice or more weekly in themorning and at night. Sixteen were randomly assigned to a control group and 16 to a nap(treatment) group. The experiment comprised two conditions of electrographically (EEG) recorded sleep for the nap group and two EEG monitored conditions of wakefulness for the controls. These conditions were scheduled from 9:35 to 11:35 a.m. and 12 hr later between 9:35 p.m. and 11:35 p.m. Measurements were obtained from: (a) a continuous 10-min auditory reaction time task, (b) a free recall task of short-term memory, (c) an activation-mood adjective check list, and (d) the Stanford Sleepiness scale. Except for memory the dependent variables of waking function were assessed 20 min before and 20 min after all conditions. Following each sleep condition the nap group as opposed to the controls showed a statistically significant improvement in reaction time performance, higher short-term retention, less reported sleepiness and elevated subjective states reflected by fice factors on the adjective mood-activation check list. Among the correlations computed the largest significant coefficients were of stage 4 and REM with posttreatment Stanford Sleepiness ratings. After naps, increased postdormital sleepiness was correlated with stage 4 and decreased sleepiness with REM sleep. Although few strikingly divergent functional effects were associated with morning and nocturanal naps, these did covary with sleep psychophysiology. It is postulated that the phase, the EEG-sleep stages and possibly the duration of accustomed naps are less salient factors influencing performance when the time since awakening until behavioral assessment can be kept constant.

Eysenck's Descriptive and Biological Theory of Personality: A Review of Construct Validity

Eysencks descriptive and biological personality theory was reviewed from the perspective of construct validity. Factor analyses have consistently identified orthogonal personality dimensions of extraversion (E), neuroticism (N) and psychoticism. Defining characteristics of each dimension converge with those identified by factor analyses of Cattells 16 PF, CPI and MMPI and average scores on the Eysenck Personality Questionnaire for 37 nations. These 3 dimensions reflecting variation of personality have been validated by differences in the degree of resemblance reflected by traits of dizygotic and monozygotic twins. Multivariate genetic analyses of responses to single items of the N and E scales have corroborated heritability of most items substantiated by conventional univariate analyses. Predictions applied to experimental substantiated by conventionald univariate analyses. Predictions applied to experimental psychological findings more frequently have validated the mediation of individual differences i...

Effects of scheduled afternoon naps and bedrest on daytime alertness

A forced-rest postulate and recuperative theory of sleep function were tested. Eighteen normal, healthy young adult males were studied in a balanced design which comprised single treatment replicates of polygraphically recorded 2:40-4:00 p.m. napping and bedrest. Under both conditions subjects were required to lie quietly in bed with eyes closed. During bedrest, stage 1 sleep episodes were allowed to intervene, but for no longer than 1.5 min simultaneously. Dependent variables of waking function were initially assessed at 12:30 p.m. for 1.2 hr and then again 20 min following the conditions from 4:20 until 5:30 p.m. Measurements were obtained from: (a) short-term memory, visual four-choice reaction time, and auditory vigilance tasks; (b) 4-7 Hz EEG theta rhythm; (c) sublingual temperature; (d) the Stanford Sleepiness Scale; and (e) mood subscales (activation, euphoria, fatigue) on an adjective check list. During bedrest compared with napping, subjects averaged significantly more: (a) stage 1 (in aggregate:...

Sleep Pattern Variations as a Function of Age in Affective Disorders

Polygraphic features of nocturnal sleep were evaluated in young adult psychiatric patients during acute unipolar depressive episodes. Averaged values and variability of polygraphic indexes were examined in 12 depressed patients under the age of 26 individually matched with a normal control group. Sleep was polygraphically recorded in the Laboratory for three consecutive nights from 12-8.00 a.m. Although average total time asleep was approximately equivalent (greater than 7.3 hr) between groups, depressives accumulated significantly: (i) less stage 4, (ii) more stage 1, (iii) vascillations among sleep stages, but (iv) most especially increased transitions into stage 1 and (v) intermittent wakefulness. The recorded sleep perturbations in young depressives were extremely variable across nights and among individuals. This was especially conspicuous across nights as reflected by significantly larger variability (SD) for: (i) transitions into stage 1, (ii) intermittent wakefulness and (iii) epsilon accumulations of stage 2. Variability (the SD) between individuals was also more substantial for: (i) total time asleep, (ii) stage 1, (iii) intermittent wakefulness, (iv) epsilon stage shifts and (v) intrusions into stage 1. The polygraphic recordings of young depressives contained anomalies reported for clinical pathologic states accompanied by physiological disregulation such as hypersomnia, narcolepsy and schizoaffective disorders. Polygraphic indexes reflecting the capacity (i) to remain asleep (means +/- SDs) and (ii) accumulate continuous sleep (SDs) indicated an imbalance of the 24-hr rest (sleep)--activity (waking) cycle was present in this constituency concomitant with affective distress. A comparison with selected cross-sectional polygraphic studies revealed that sleep cycle aberrations in young adult depressives were less intense than those which become exacerbated as a function of advanced age. By contrast to prepubertal children or postadolescent young adults who are depressed, elderly accumulate: (i) lower total sleep times, (ii) less proportions of stages 3-4 and (iii) remain awake longer. It is concluded that sleep-polygraphic anomalies in postadolescent depression are an attenuated form of the REM-NREM cycle perturabation endemic to affective disease occurring with advanced age or senescence.

Demography of DSM-III Borderline Personality Disorder (PD): A Comparison with Axis II PDS, Affective Illness and Schizophrenia Convergent and Discriminant Validation

Demographic characteristics of borderline personality disorder (PD) defined according to DSM-III criteria were compared with those found for schizophrenia, affective illness, and other Axis II PDs. Borderline PD, unlike affective illness and most other Axis II PDs, usually occurs before the age of 30. By contrast to antisocial PD and schizophrenia, borderline PD usually occurs after the age of 25. For borderline PD (N = 280) average age was significantly more homogeneous compared with affective illness (N = 157) and Axis II PDs (N = 71) across 9 studies. By contrast, variability for 63 predominantly male schizophrenics in 3 studies was significantly less, reflecting the younger age at admission compared with borderline PD (N = 84). According to predictions based upon an age-of-risk hypothesis (Dahl, 1985) for 106 borderline PD patients, a significantly lower percentage were > or = 40 years of age than diagnostic controls (N = 181) predominantly with DSM-III affective illness. Borderline PD is predominantly diagnosed in females either single or who have been divorced compared with Axis II PDs and affective illness, to a lesser extent. Unlike antisocial PD, as well as schizophrenia, the preponderance of male and single/divorced patients usually occur significantly less than for borderline PD. Borderline PD usually occur significantly less than Axis II PDs, affective illness and schizophrenia and ethnic minorities, particularly Afro-Americans. These differences in ethnic/racial distribution are explained in terms of two hypotheses. From the perspective of demographic variables, borderline PD closely converges with neither (a) schizophrenia, (b) antisocial PC, (c) other Axis II PDs, nor (d) affective illness. Evidence for discriminant and convergent validation of these data is provided by (a) cluster analyses and intersample pairwise contrasts, as well as comparisons with (b) clinical samples selected on the basis of DSM-III-R and criteria of the (c) Diagnostic Interview for Borderline Patients, (d) a longitudinal case registry study conducted in Denmark, and (e) prospective surveys conducted among (i) North Carolina community residents and (ii) first degree (nonpatients) relatives of psychiatric patients in Iowa.

Individual Variations in the Sleep of Depression

Variations in the intensity or severity of affective disorders were evaluated relative to perturbations in nocturnal sleep physiology. Individual variations in polygraphic features of the sleep cycle based upon psychopathologic scale ratings were investigated in two constituencies (Ns = 6) for 8 hr during 1-3 consecutive nights. The constituencies consisted of twelve young adult (18-25 years) nonpsychotic unipolar depressed psychiatric patients with a primary affective illness and an age-matched normal healthy control group (N = 8). The severely versus mildly depressed patient subgroups scored significantly higher on the Hamilton, Beck and Zung psychopathologic rating scales, indicating a larger magnitude of depressive symptomatology. The average value for total time asleep was 6.1 hr in severely versus 7.8 hr among the mildly depressed patients and controls. EEG-sleep of the severely versus mildly depressed patients and controls contained significantly less stages 2 and 3. Although total time asleep was almost identical in the mildly depressed constituency compared with controls, patients accumulated significantly more of stages 2 and 3. Both patient subgroups exhibited a significantly shorter REM latency than controls. REM latency was reduced to a significantly lower level in the severely versus mildly depressed patients. A significant decrease of REM cycle duration occurred in the polygraphic sleep recordings of severely depressed patients compared with the age-matched controls. The shortened REM latencies indicate a disinhibition of neural processes that would normally delay appearance of the initial REM episodes during nocturnal sleep. The present study generally extends and confirms finding on nocturnal EEG-sleep disturbances in depression associated with the severity of affective illness, particularly the disrupted REM cycle and shorter REM latency.

Nocturnal Electrographic Features of Frequently Changing-Irregular Sleep-Wakefulness Rhythms

Polygraphic characteristics of nocturnal sleep associated with frequently changing-irregular rest-activity schedules were investigated in healthy young adults. Two groups each of 12 male university students were classified according to a priori criteria as either: (a) controls who slept regularly for 7--8 hr at night or (b) whose retiring and arising times combined varied chronically +/- 1.5 hr. Sleep was recorded during three consecutive 8-hr nocturnal periods at fixed clock times. Polygraphic indices generally reflected greater discontinuity and fragmentation associated with the nocturnal sleep in the young adults whose 24-hr rest-activity cycle tended to be frequently changing-irregular. The significantly: (a) larger absolute quantities of (i) transitional stage 1 sleep, (ii) intermittent wakefulness and (b) increases stage shifts provided some indication that the intrasleep cycle becomes disturbed when rest-activity schedules follow no predictable pattern in the everyday environment. Despite, or because of, the enforced hour (11:30 p.m +/- 30 min) for retiring, it is possible that the capacity to fall asleep had become phase-delayed among subjects with irregular rest-activity schedules who experienced more initial wakefulness (on average) before sleep onset stage 1. Finally, the recorded sleep perturbations associated with frequently changing-irregular schedules were extremely variable across nights and among individuals. This was especially pronounced on a nightly basis as reflected by significantly larger variability (SDs): (a) in the latency to sleep onset, for (b) total time asleep, (c) intermittent wakefulness, and (d) the ultradian (90-min) REM cycle. Variability (the SD) between individuals was also more substantial for these same polygraphic measures at statistically significant levels.

Effects On The Polysomnogram And Waking Electrocorticogram Of Ad-Libitum Extended-Delayed Sleep

The influence arising from an ad-libitum extended-delayed sleep regime on the temporal distribution of REM, slow-wave NREM (stage 2) cycle durations, and waking EEG concurrent with auditory vigilance performance, was evaluated. Subjects were 16 normal healthy young adult males aged 18–24 years who slept 7–8 hr nocturnally. The experiment included an imposed 12–8:00 a.m. control condition and ad-libitum treatment of electrographically recorded laboratory sleep. On the control night the time for retiring was scheduled for 12:00 a.m. and awakening at 8:00 a.m. During the ad libitum treatment the subject was allowed to retire and awaken largely at his own inclination. From a central (C4–A1) electrocorticogram continuously recorded 1 hr after awakening, during evaluations on auditory vigilance, 1.5-sec epochs of 8–13 Hz alpha rhythm following task-relevant (signal) stimuli were integrated and rectified. The accumulation of slow-wave sleep declined systematically across cycles during both treatments. This atten...

Disturbances in Diurnal Rhythms Following a Night of Reduced Sleep

Twenty-four healthy young adult males who slept regularly for 7--8 hr completed nonlaboratory appraisals based upon dependent variables which reflected daytime alertness at 4-hr intervals from 8:15 a.m. until midnight once: (a) initially after having experienced disturbed nocturnal sleep and (b) following a control night. A statistically significant 1.8 hr average decrease in total sleep was reported during the disturbed night X = 6.0 hr) versus the control condition (X - 7.8 hr) which primarily resulted from delays and/or difficulties in falling asleep. Following disturbed nocturnal sleep a significant decline in alert wakefulness occurred predominantly at: (a) midday (12:00 noon) and/or (b) in the afternoon (4:00 p.m.) as assessed by 4 of 6 adjective check list scales and lowered body temperature levels. After the disturbed night, compared with the control condition, there was a significant diminution of the amplitude or variability in the diurnal rhythm of: (a) body temperature; (b) Stanford Sleepiness Scale ratings: (c) adjective check list scores on the (i) activation, (ii) fatigue, and (iii) performance efficiency subscales. The amplitude reduction in the diurnal rhythm was associated with a general trough during the middle of the wakefulness cycle which extended from 12:00 noon until 8:00 pm.m when various arousal indices following regular sleep attained maximal values. Subjects subsequently slept significantly longer by 1.3 hr than on the immediately preceding night of reduced sleep. There was a significant negative correlation between relative levels of temperature in the morning and sleep duration reported on the disturbed night. Greater accumulations of sleep reported during the disturbed night occurred when temperature levels corresponded with values in the control condition.

Psychobiology and Pathologies of Human Sleep

This review is principally devoted to major sleep pathologies which pose exemplary problems for cardiology, neurology, psychiatry, physiology, internal, and pulmonary medicine. Fundamental information about the psychobiology and biorhythmic aspects of normal nocturnal slumber is presented and related to polygraphic findings on sleep pathology. Clinically significant increases in blood pressure, respiratory rate, cardiac irregularities and gastric acid secretion all occur in phase with the nocturnal sleep cycle. Exacerbations of duodenal ulcer and coronary-artery disease including cardiac arrhythmias at night have all been shown to coincide with REM sleep. Stereotyped abnormal leg movements associated with nocturnal myoclonus are due to activity of anterior tibialis or quadriceps muscles and occur episodically during the entire sleep period especially in the NREM-stages. Sleepiness has frequently been observed to accompany hypothyroidism and stages 3-4 are drastically reduced. The major symptoms of narcaol...