Task order choices in cognitive and perceptual-motor tasks: The cognitive-load-reduction (CLEAR) hypothesis

A core question in the study of the dynamics of cognition is how tasks are ordered. Given two tasks, neither of which is prerequisite for the other and neither of which brings a clearly greater reward, which task will be done first? Few studies have addressed this question, though recent work has suggested one possible answer, which we here call the cognitive-load-reduction (CLEAR) hypothesis. According to the CLEAR hypothesis, there is a strong drive to reduce cognitive load (to "clear one's mind"). Given two tasks, one of which is more cognitively demanding than the other, the more cognitively demanding task will tend to be done first. We tested this prediction using a novel method inviting participants to freely choose when to perform each of c = 5, 10, or 15 items per category in item-generation tasks relative to b = 10 box-moving tasks. The box-moving tasks were cognitively undemanding relative to the item generation tasks, whose cognitive difficulty presumably grew with c. A full half of our n = 122 participants chose to complete all of the c tasks before performing any of the b tasks, and most other participants chose to complete a majority of the c tasks before any of the b tasks. This result is consistent with the CLEAR hypothesis. Speed on the box-moving task decreased the later the category-generation task was completed, supporting another CLEAR prediction. The general method used here provides direction for future work on task order choices in cognitive and perceptual-motor tasks.