The effect of psychological stress upon decisions processes and the speed and precision of tracking movements : a study of the effect of sleep deprivation and disturbance.

Twelve youths were deprived of sleep for 48 hours. Each subject was tested for 15 minutes at four-hourly intervals, on each of two tasks (a) of mirror tracing and (b) of step input tracking using an instrument named the stressalyser.The same subjects were again tested one week later. They were than allowed to sleep when ever they wished, but were aroused at four-hourly intervals in the night, some 15 minutes before the times, near 1:00 a.m., and 5:00 a.m., at which they were tested during the previous study of complete deprivation.