PubMed Health⌕ Search

Biomedical subjects

D Koulack

Publications and source records attributed to D Koulack.

At least 19 recordsLinked to original sources
PubMed1997

Recognition memory, circadian rhythms, and sleep.

One set of 20 subjects learned a list of words early in the morning while another set of 20 learned the same material in the midafternoon. Half of the subjects (n = 10) were tested after an intervening four hours of sleep, while the other 10 were tested after four hours of waking activity. Subjects in the afternoon groups performed better on a recognition task than those in the morning groups, while subjects who had intervening periods of sleep between learning and testing performed better than their counterparts who remained awake. Finally, those subjects who learned in the afternoon and slept prior to testing did best on the recognition task, while those who learned in the morning and remained awake did worst. These results are consistent with the notion that both sleep and circadian rhythms play a role in the memory process.

Arousal↗
PubMed1994

Recognition memory, sleep and circadian rhythms.

In Experiment 1, subjects learned a list of words and were tested for recognition of them 24 hours later. For the delayed sleep group, learning was followed by a period of wakefulness; for the immediate sleep group, it was followed by a period of sleep. Retention was significantly better for the immediate sleep group, consistent with the notion that consolidation is enhanced by the interpolation of sleep shortly after learning. In Experiment 2, subjects were tested approximately eight hours after learning. The normal waking group learned and was tested after a period of daytime weakfulness; the normal sleep group learned and was tested after a period of nighttime sleep; and the sleep deprivation group learned and was tested after a period of nighttime wakefulness. Retention for the normal sleep group was superior to that of the normal waking group, thus extending the commonly observed effect of sleep on memory to the domain of recognition memory. However, we found that retention was not better for the normal sleep group than for the sleep deprivation group suggesting that the effect of sleep on memory may be partially due to circadian rhythms.

Arousal↗
PubMed1993

Laboratory sleep patterns and dream content of type A and B scoring college students.

The suggestion that there may be a discrepancy between subjective and objective measures of sleep led us to explore the sleep and dreams of 7 Type A and 7 Type B scorers in our laboratory over a three-night period. In earlier studies, Type A scorers had indicated that their sleep was somewhat more disturbed and their dream content generally more active and negative in tone than that of Type B scorers. However, in this study the only differences were that Type A scorers had a greater number of body movements and greater dream recall than did Type B scorers. These results seem to indicate that the impression Type A scorers have of the quality of their sleep and dreams may be a function of their waking life-style.

Adult↗
PubMed1992

Sleep parameters of type A and B scoring college students.

162 subjects, half of whom scored between 310 and 420 and half of whom scored between 184 and 256 on the Survey of Work Style questionnaire, participated in this study. The former group was defined as Type A scorers and the latter as Type B scorers. Type A scorers had more trouble falling asleep, had more nightmares, and spent less time asleep than did Type B scorers. However, there was no difference between the two groups in the amount of dream recall or on the morningness/eveningness continuum.

Adult↗
PubMed1987

Dreams and contemporary stress: a disruption-avoidance-adaptation model.

A disruption-avoidance-adaptation model is proposed to provide a framework for understanding the seemingly disparate findings from studies of dream function. The model is based on the notion that there is an oscillation between disruption of sleep caused by dreaming about a stressful stimulus followed by an avoidance of the stimulus in order to achieve homeostasis. The oscillation is postulated to continue until there is adaptation to the disruptive stimulus. Continuity is assumed to exist between waking and sleeping experience.

Adaptation, Psychological↗
PubMed1985

Sleep, dreaming, and adaptation to a stressful intellectual activity.

Sixteen male subjects slept in the laboratory for 4 consecutive nights. Night 1 was an adaptation night and night 2 was a baseline night of uninterrupted sleep. On nights 3 and 4 subjects were asked to complete "intelligence" tests prior to sleep. One half of the subjects attempted to complete difficult versions of "intelligence" tests without knowing that they could not be completed in te time allotted. The other subjects were given easier versions of the same tests that they were able to complete in the time allotted. Night 3 was a night of uninterrupted sleep and night 4 involved REM period awakenings for the purpose of dream collection. Stressful manipulation consisted of telling the subjects before the administration of either set of tests that an average university student should complete most of the items within the allotted time. On night 3 both groups showed a significant increase in sleep latency and a significant decrease in REM density compared to the baseline night. On night 4 subjects in the difficult condition experienced significantly more anxiety in their dreams and somewhat higher levels of incorporation of the presleep material than subjects in the easy condition. Our findings suggest that following a stressful experience uninterrupted sleep has more short term adaptive value than a procedure which enhances dream recall and that subjects who incorporate elements from a presleep stressful event into their remembered dreams show less adaptation on awakening than subjects who do not.

Adaptation, Psychological↗
PubMed1980

Dream affect and the menstrual cycle.

Ten women subjects exhibited no evidence of waking mood change or differential dream recall as a function of their menstrual cycles. These findings indicate that, with the use of simple screening procedures, women as well as men can and should be used as subjects in research on sleep and dreams.

Adolescent↗
PubMed1978

Field dependence and the effect of REM deprivation on thirst.

Recently a number of studies have concerned the possible function of rapid eye movement (REM) sleep and the mastery of stress. The present study was designed to explore the possibility that REM sleep might play a function in reducing the potency of a stressful physiological stimulus, thirst, as well as the possibility that such a function might be specific to individuals falling at different points along the field-dependence dimension. While there was no difference between REM deprivation and non-REM awakening nights in subsequent morning thirst, there was a significant interaction between field dependence and night on morning thirst measures for 10 college students. These results are discussed in light of previous work on stylistic differences in dreaming and their possible role in adaptation to stress.

Adaptation, Physiological↗
PubMed1977

[Model for the recall of dreams upon waking, proposed to account for impairment of memory of dreams].

A two-stage model is presented to account for the difficulties found in sleep learning and dream recall. The model assumes that information processing in a short-term memory store facilitates subsequent retrieval from long-term storage and that such processing is impaired during sleep. As a result, it is suggested that information confronting the sleeping person very likely can only be retrieved if an awakening occurs during the life of the short-term memory trace. However, it is proposed that material occurring during or shortly after awakening, competes with information occurring during sleep for space in the limited capacity processing system, with the most important being favored for processing. Interference and repression are included as additional factors affecting retrieval from longterm storage.

Conscience↗