Caffeine selectively mitigates cognitive deficits caused by sleep deprivation.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 34014758 · doi:10.1037/xlm0001023
What was done
Researchers evaluated the effect of caffeine on visual vigilant attention (Psychomotor Vigilance Task, PVT) and placekeeping (UNRAVEL task) following sleep deprivation. A total of 276 participants performed baseline testing in the evening and were randomized to either stay awake overnight in the laboratory or sleep at home. In the morning, participants were administered a capsule containing either 200 mg of caffeine or placebo before repeating the cognitive tests.
What was found
Sleep deprivation impaired performance on both vigilant attention and placekeeping tasks. Caffeine counteracted the impairment in vigilant attention but did not significantly affect placekeeping for most participants, though it reduced the number of sleep-deprived participants who failed to maintain criterion accuracy. The abstract reports no numerical values, effect sizes, or test statistics.
Why it matters
This trial suggests that sleep deprivation impairs procedural placekeeping through pathways independent of visual vigilant attention. While caffeine can mitigate simple vigilance drops, it may be insufficient to prevent procedural errors during complex, multi-step tasks in sleep-deprived settings.
Limits
The abstract provides no raw numbers, effect estimates, or confidence intervals. The rested control group slept at home without objective sleep tracking reported in the abstract, and only a single dose of caffeine (200 mg) was evaluated.
Cited by
- supports Caffeine increases arousal but does not restore clear cognitive thinking after sleep deprivation.