The role of inhibition in task switching: Evidence from an n-back task

Task switching is a well-established paradigm for assessing cognitive flexibility. However, the precise role of inhibition in task switching remains unclear. This study investigates the effects of inhibition on switch costs in tasks requiring participants to judge whether the magnitude (small vs. large) or parity (odd vs. even) of a number was the same as that presented in previous trials. To this end, an n-back task was embedded in the task-switching paradigm. The results of Experiment 1 demonstrated that, in comparison to the 1-back condition, switch costs were significantly reduced in the 2-back condition, which involved an increased inhibition process. The selective increase in inhibition in some trials in the 1-back condition (Experiment 2) and the carryover of inhibition (Experiment 3) significantly reduced the switch costs. These findings indicate that the enhanced inhibition of task-irrelevant information can facilitate cognitive flexibility in task switching and reduce switch costs, providing novel empirical evidence for the inhibition mechanism underlying task switching.