Chronic Sleep Duration Research Articles

Chronic short sleep duration lengthens reaction time, but the deficit is not associated with motor preparation.

The purpose of this study was to investigate the association between chronic sleep duration and reaction time performance and motor preparation during a simple reaction time task with a startling acoustic stimulus in adults. This cross-sectional study included self-reported short sleepers (n = 25, ≤ 6 hr per night) and adequate sleepers (n = 25, ≥ 7.5 hr per night) who performed a simple reaction time task requiring a targeted ballistic wrist extension in response to either a control-tone (80 dB) or a startling acoustic stimulus (120 dB). Outcome measures included reaction times for each stimulus (overall and for each trial block), lapses, and proportion of startle responses. Chronic short sleepers slept on average 5.7 hr per night in the previous month, which was 2.8 hr per night less than the adequate sleepers. Results revealed an interaction between sleep duration group and stimulus type; the short sleepers had significantly slower control-tone reaction times compared with adequate sleepers, but there was no significant difference in reaction time between groups for the startling acoustic stimulus. Further investigation showed that chronic short sleepers had significantly slower control-tone reaction times after two blocks of trials lasting about 5 min, until the end of the task. Lapses were not significantly different between groups. Chronic short sleep duration was associated with poorer performance; however, these reaction time deficits cannot be attributed to motor preparation, as startling acoustic stimulus reaction times were not different between sleep duration groups. While time-on-task performance decrements were associated with chronic sleep duration, alertness was not. Sleeping less than the recommended sleep duration on a regular basis is associated with poorer cognitive performance, which becomes evident after 5 min.

The Influences of Acute and Chronic Sleep Duration on Endurance Performance in Female Youth Athletes

The Influences of Acute and Chronic Sleep Duration on Endurance Performance in Female Youth Athletes

Aspects of personality associated with irregular sleep habits in young adults

Studied psychological correlates of irregularity in chronic sleep routines. The California Psychological Inventory (CPI) and Cornell Medical Index (CMI) were administered to two groups of 18 male university students who were categorized as either irregular sleepers or control Ss. The control group was composed of persons who habitually slept from 12-8:00 A.M. Irregular sleepers were defined as those whose retiring and awakening times continuously varied by about 2 to 4 hours. Control Ss scored significantly higher than the irregular group on the CPI scales of Do (dominance), Sy (sociability), Sa (self-acceptance), Sc (self-control), Ac (achievement via conformance), and Ie (intellectual efficiency), but lower on the Fx (flexibility) scale. There were no significant differences between the groups in scores on the CMI or average sleep length recorded over 2 weeks. The present findings indicate that in young adults, personality functioning is related more closely to the regularity of nocturnal sleep routines than to differences in chronic sleep duration. It is postulated that stable or irregular sleeping patterns are largely dependent factors not only of the psychological characteristics that distinguished the groups, but as yet unspecified constitutional and sociocultural antecedents of the human sleep response.

Behavioral and psychological correlates of a difference in chronic sleep duration

The relationship between chronic differences in sleep duration and waking behaviors was explored by comparing two groups of 10 healthy male university students who regularly slept nocturnally for 7–8 h or for 9.5–10.5 h. Measurements were obtained of sublingual temperature, from a 45 min Wilkinson auditory vigilance task and a mood adjective check list 30 min after awakening in the morning, at midday and in the early evening following an electroencephalographically recorded night of sleep. In both subject groups body temperatures increased from morning to early evening, while misses on the vigilance task correspondingly declined during the day. The average daily level of oral temperature and performance were significantly lower in the 7–8 h (control) group than in the long sleepers. Positive mood states (Cheerful, Energetic, General Activation, High Activation) were significantly greater and negative affects (Anger-Hostility, Depression) significantly less in the long sleepers. As a result of the mean difference in total sleep time existing between groups control subjects averaged significantly less stage 2, and stage REM sleep. It was postulated that there were behavioral deficits in the control group attributable either to selective sleep stage deprivation or to the general consequence of reduced sleep per se or to both of these factors.