Total sleep deprivation and cognitive performance: The case for multiple sources of variance

Abstract

The present chapter reviews and summarizes some of the major findings of the studies of the impact of sleep deprivation on cognitive performance over the past half century. The studies discussed are limited to instances of total sleep loss and support the argument that total sleep loss may impact different cognitive functions differently. Some cognitive variables may be more sensitive to sleep loss than others and some cognitive variables may be more sensitive to the homeostatic pressures of accumulated wakefulness, while others may be more sensitive to the impact of the circadian cycle. Three types of data were chosen for illustration: 1) those that are descriptive of the major effects of short- to-mid term (24-48 hrs) or long term (72 hrs and longer) sleep deprivation; 2) those that are descriptive of disassociations of the effects of sleep deprivation on cognitive performance; and 3) those that describe differential effects of treatments on different cognitive performance tasks. Evidence is presented to show that the effects of sleep deprivation on cognitive performance are not uniform, either with respect to task or with respect to the time since the last sleep epoch. The propositions discussed in the present chapter have important theoretical and practical implications. If more than one neural mechanism is involved in performance decrement due to sleep deprivation and sleep restriction at any moment, then any proposed intervention that targets only one of the mechanisms cannot be fully successful in ameliorating the effects of sleep loss. Multiple sources of variance in causing performance decrement require multiple forms of treatment to eliminate or reduce decrement. © 2008 Springer Science+Business Media B.V.