The role of time on task in multi-task management.

Extreme resistance to switching tasks can lead to cognitive tunneling. A four-attribute decision model of task management under load was recently built with an assumption of the resistance to switching tasks. Recent theory also suggests switch resistance declines with time on task, and this was tested in the current experiment. Participants managed sequential performance of four concurrent tasks in a multi-attribute task battery. The over-time trends in switch resistance, as related to both cognitive load, and stability of the tasks, were examined. Switch resistance showed no decrease over time overall, contradicting the existing theory. Instead, increases in switch resistance were found with an increased working memory load, and within periods of increased tracking task instability, shedding light on time-on-task effects and cognitive tunneling.