The effects of planned rest on complex task performance in industrial workers

Previous research into the effects of shift work on worker reaction time and performance levels on cognitive performance tasks have established that alertness and performance levels decline as a function of both the length of and the number of shifts worked in a row (Schultz & Schultz, 1986; Rosa & Bonnet, 1993; Muchinski, 1993). In this study the use of a planned rest period was employed to evaluate the effects on performance, while working night shift. During alternating weeks seven custodial workers either followed their regular work schedule, or were given the opportunity for, a 20 minute rest period during their shift. All participants were tested before and after each shift to measure the changes in their levels of alertness and performance as measured by simple and complex reaction time and simple and complex cognitive performance tasks. The results indicated that periods of rest were associated with decreased reaction times (i.e., improvements in performance), though this effect held regardless of the time of testing (i.e., before vs after sleep). Though the results are not entirely consistent with previous research, they do suggest that indices of performance, such as immediacy of response, are improved for night shift workers provided with rest in industrial settings.