Sleep duration, chronotype, health and lifestyle factors affect cognition [pdf]
Alcohol consumption and cognition
- Many note the study finds abstainers score lower cognitively than drinkers; this clashes with other research linking alcohol to brain harm.
- Several argue this is likely confounded:
- Abstainers may include former heavy drinkers or people who quit due to illness.
- People with serious health problems or lower income may drink less.
- Cultural and religious abstinence (e.g., in “dry” cultures) complicates interpretation.
- Some see weekly moderate drinking as possibly tied to social connections and novelty-seeking, which might track with cognition, but emphasize this is correlation only.
- Others insist there’s no plausible long‑term cognitive benefit of alcohol, despite these associations.
Sleep duration, quality, and practicality
- Commenters accept that 7–9 hours is “normal” physiologically, but many say this is hard to achieve with commuting, kids, and modern work.
- Several report functioning well on 6.5–7 hours and think the 8‑hour target is overstated; others track sleep carefully and find more sleep clearly improves performance and recovery.
- Some note that very long sleep often coincides with poor sleep quality, prior deprivation, depression, or illness.
- Confusion that the paper finds little link between subjective sleep quality and cognition; people cite other work and athletic experience where sleep quality strongly affects performance.
Chronotype (night owls vs larks)
- Night owls in the thread often feel more productive and creative late at night, citing fewer distractions and personal history.
- Others say they work best in early morning quiet, or that their chronotype shifted with age or kids.
- Consensus: forcing people to work against their chronotype feels harmful; any cognitive differences may come from social schedules misaligned with biology.
Methodological and interpretation concerns
- Multiple commenters stress correlation vs causation, “just‑so stories,” and the need to control for ex‑drinkers, health status, exercise, and socio‑cultural factors.
- Some think mixed findings on alcohol and sleep quality imply subtle or weak effects rather than clear causal stories.
Other factors discussed
- Personal reports on creatine, caffeine (including “coffee then nap”), nasal breathing, deviated septum, and sleep apnea highlight many unmeasured variables that might affect cognition and sleep.