Circadian Patterns of Sleep, Sleepiness, and Performance in Older and Younger Adults
Bibliographic record
Abstract
STUDY OBJECTIVE: To compare circadian patterns of sleep, subjective sleepiness, and psychomotor performance in older and younger adults. DESIGN: Controlled experimental laboratory study. SETTING: General Clinical Research Center. PARTICIPANTS: Healthy older adults (n = 17, mean age 76 years) and healthy younger adults (n = 19, mean age 23 years). INTERVENTIONS: Subjects lived for 60 consecutive hours on a 90-minute sleep-wake cycle (30 minutes in bed, 60 minutes awake). Electroencephalographic recordings were conducted during bedrest periods. Self-ratings and psychomotor performance tests were conducted during 60-minute wake periods. MEASUREMENTS AND RESULTS: Data were analyzed with cosinor and linear mixed models. Amplitude and phase of the core body temperature rhythm did not significantly differ by age group. Older adults had significantly reduced mean levels and amplitude of rhythms in total sleep time and sleep efficiency and increased mean levels and amplitude of rhythms in sleep latency and wake after sleep onset. Age groups did not differ in mean level of subjective sleepiness, but older adults had reduced amplitude. Older adults had worse overall psychomotor performance, with evidence of larger circadian amplitude in some of these rhythms. Age groups did not differ on the phase position of any rhythm. CONCLUSIONS: Older adults had a lower level and smaller circadian variation of sleep propensity compared with younger adults, whereas wakefulness and psychomotor performance rhythms tended to show increased circadian variation among older subjects. These findings likely result from a combination of age-related changes in cortical function, homeostatic sleep mechanisms, and circadian regulation.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".