The Effects of Block Duration and Task Demands on the Experience of Task Unrelated Thought

Abstract

Evidence indicates that the degree to which attention can be maintained upon the task in hand depends upon both the type and duration of the task. Two experiments investigated the relationship between task irrelevant thinking and block duration in two types of task. In Experiment One, a vigilance task was compared to a fluency task and in Experiment Two a verbal encoding task was compared to a fluency task. In both tasks we investigated the hypothesis that block duration mediated changes in thinking would be smallest for tasks which rely heavily on controlled processing (the fluency task). Results were consistent with expectations and indicated that the report of thoughts with no relationship to the task in hand increased with block duration in the vigilance task (Experiment One) and the verbal encoding task (Experiment Two). In neither experiment did block length effect thinking during the fluency task. These results are broadly consistent with the assertion that tasks that cannot be readily automated, maintain attention upon the task at hand in a superior fashion as the duration of the block increases. The implications of these results for our understanding of the process responsible for our conscious awareness of a stimulus and our ability to plan and anticipate events are discussed.