Sleep deprivation and cognitive performance

Insufficient sleep is a hallmark of our modern busy society, but burning the candle at both ends does not come without a cost. The present chapter provides a selective overview of the major effects of sleep deprivation on cognition, including its effects on alertness and vigilance, sensory perception, emotion, learning and memory, and executive functioning. Established research suggests that, without sufficient sleep, simple reaction time is slowed, attentional lapses become longer and more frequent, and in general, behavior becomes increasingly inconsistent and unstable. There are notable individual differences in the ability to resist sleep loss, for which biological or psychological markers have yet to be unequivocally identified. Sleep deprivation can impair some sensory-perceptual processes, particularly visual processing. In addition, sleep loss worsens mood, lowers frustration tolerance, and biases the perception and expression of emotion toward negative affective states. Sleep deprivation also affects memory by reducing encoding when it precedes learning and impairs consolidation of memory traces when it occurs after learning. Some, but not all, aspects of higher order executive functions are impaired by sleep deprivation, but the data in this regard remain inconclusive. Further research will be necessary to disentangle the extent to which deficits in higher order cognitive functions are due to primary executive system dysfunctions versus impairments of more elementary processes such as alertness, attention, and cerebral interconnectivity.