Abstract: Task switching is an important paradigm in the study of executive control. Switch cost refers to the performance difference in task-switch and task-repeat trails, which is an indicator of executive control. The mechanisms of switch cost are complex and there are many controversies in this filed. Three of the most popular theories were reviewed in this paper: task-set reconfiguration, task set priming and task set inertia, together with experimental evidence supporting or refuting these theories.

Key words: task switching, executive control, switch cost