Effect of sleep loss in a combined tracking and time estimation task

The present study examines whether monitoring and control behaviour are affected by sleep loss and fatigue. The effects of one night of sleep loss are investigated in a dual-task consisting of a monotonous tracking task that requires continuous control behaviour and a time estimation task that requires monitoring with an 'open-loop' character. In the tracking task subjects had to keep a square cursor in the centre of a U-shaped target. In the times estimation task subjects had to estimate consecutive time intervals and to respond when an interval had ended. There were three experimental conditions. In the first condition a clock was presented continuously on the screen; thus, subjects had a clear notion of the time course.