Inhibition and the right inferior frontal cortex

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neurobiology

Background:

• The precise localization of cognitive functions within the prefrontal cortex (PFC) remains a subject of debate.
• Historically, inhibition has been linked to various PFC regions, including dorsolateral (DLPFC), inferior frontal (IFC), and orbital frontal cortex (OFC).
• Inhibition is theorized as a key mechanism for PFC-mediated executive control over subcortical and posterior brain regions.

Purpose of the Study:

• To review existing evidence on the neural correlates of inhibition, specifically response inhibition and task-set inhibition.
• To critically evaluate the functional localization of inhibition within the prefrontal cortex based on neuroimaging and lesion studies.
• To propose a refined understanding of the PFC's role in inhibitory control.

Main Methods:

• Systematic review of neuroimaging studies (e.g., fMRI) investigating inhibition.
• Analysis of human lesion-mapping studies to identify brain regions critical for inhibitory functions.
• Synthesis of evidence to reconcile conflicting findings regarding PFC involvement in inhibition.

Main Results:

• Neuroimaging studies implicate multiple PFC regions in inhibitory control, showing diverse activation patterns.
• Human lesion-mapping studies provide stronger evidence, localizing inhibitory functions specifically to the right inferior frontal cortex (IFC).
• This contrasts with broader localizationist views that assign inhibition to DLPFC or OFC.

Conclusions:

• The right inferior frontal cortex (IFC) appears to be a critical region for inhibitory control, challenging theories of widespread PFC involvement.
• Future research should explore the generalizability of right IFC's inhibitory role across different cognitive tasks and its network interactions.
• Refining the understanding of inhibition's neural basis is essential for advancing theories of executive function.