Your Brain Lies to You About How Impaired You Are
The most dangerous thing about sleeping less than 7 hours is not the tiredness. It is the confidence. A landmark study by Hans Van Dongen at the University of Pennsylvania tracked participants restricted to 6 hours of sleep per night for two weeks. Their cognitive performance declined steadily across every measure. But when asked to rate their own alertness, participants reported feeling only slightly impaired, even as their reaction times and decision accuracy fell to levels equivalent to 24 hours of total sleep deprivation. The brain, running low on rest, loses the ability to accurately assess its own condition. You feel functional. The prefrontal cortex, the region governing judgment, planning, and impulse control, is quietly going offline.
