Time of day effects in simple repetitive tasks: Some possible mechanisms

A brief review of the literature, and three experiments, are presented which investigated time of day effects in human performance at simple repetitive tasks (i.e. tasks involving little or no ‘working memory’ load) The goal was to differentiate between a ‘capacity’ based explanation of the effects, concerned with changes in the general rate of information processing, and a ‘strategy’ based one concerned with the amount of information processed at each decision point. The strategy based explanation appeared to be the more suitable, accounting for the surprising heterogeneity in time of day function that was found for such tasks in the literature, and for the results of the three experiments. It would appear that there might be a general tendency for people to become faster but less accurate as the day wears on.