Cognitive Neural Mechanism of Backward Inhibition and Deinhibition: A Review

Abstract

Task switching is one of the typical paradigms to study cognitive control. When switching back to a recently inhibited task (e.g., "A" in an ABA sequence), the performance is often worse compared to a task without N-2 task repetitions (e.g., CBA). This difference is called the backward inhibitory effect (BI effect), which reflects the process of overcoming residual inhibition from a recently performed task (i.e., deinhibition). The neural mechanism of backward inhibition and deinhibition has received a lot of attention in the past decade. Multiple brain regions, including the frontal lobe, parietal, basal ganglia, and cerebellum, are activated during deinhibition. The event-related potentials (ERP) studies have shown that deinhibition process is reflected in the P1/N1 and P3 components, which might be related to early attention control, context updating, and response selection, respectively. Future research can use a variety of new paradigms to separate the neural mechanisms of BI and deinhibition.

Keywords: backward inhibition; cognitive control; deinhibition; n-2 repetitive costs; task switching.

FIGURE 1

The illustration of the sub-process in the ABA (BI) and CBA (base) condition. Inhibiting A(C) means that both the task A and C should be inhibited when performing task B, while task A needs more inhibition than task C. Inhibiting A (in gray color) means the residual inhibition of task A.

FIGURE 2

Illustration of the disassociation between inhibition and deinhibition in task sequence with three different tasks of increasing difficulty. The letter with the smallest size indicates that a particular task is easiest, while the letter with largest size indicates that it is the most difficulty one.