Effects of sleep loss on sustained cognitive performance during a command and control simulation

Because of low cognitive demands and infrequent performance assessment, previous sleep-loss studies may have provided conservative estimates of the cognitive deficits that can occur during sustained, intensive, military operations. The research described here addresses the limitations of earlier studies by requiring and measuring performance on a continuous basis in a computerized laboratory environment. During a 54-h period of wakefulness, subjects were required to continuously monitor and act upon information being transmitted over a communication network while their performance on cognitive tests, which were embedded in and distributed around the message traffic, was continuously evaluated. The results show that this cognitively demanding environment produces greater mood and performance decrements as a function of sleep loss than previous, less-demanding studies. The methodology is described in detail, and the implications of the experimental findings are discussed.