A recently published study examined how caffeine counteracts the loss of performance caused by lack of sleep. The result is clear and underlines the importance of sleep.

How caffeine affects cognition during sleep deprivation

It is well known that sleep deprivation has negative effects on cognition. The research team led by psychology professor Kimberly Fenn therefore investigated to what extent the increase in caffeine can counteract this.

The 276 subjects were initially asked to complete a simple task that required little attention. There was also a difficult task to solve in which the participants had to complete several steps in a specific order – no steps could be skipped or repeated.

“We found that sleep deprivation impaired performance on both task types and that caffeine intake helped people successfully complete the easier task,” study author Fenn said in a Michigan State University news release. However, the intake of caffeine mostly had little effect on the more difficult task.

Conclusion: Caffeine cannot replace sleep

While caffeine can help you stay awake and get a task done, it does little to prevent procedural errors that can lead to medical errors or car accidents, for example. “Caffeine increases energy, reduces drowsiness, and may even improve mood, but it certainly doesn’t replace a full night’s sleep,” says Fenn.