Neural Substrates of Inhibitory Control: A Review and Critique

Inhibitory control is difficult to study in behavioral experiments because of its nature; a successful inhibition act does not manifest overtly, thus cannot be directly observed and measured (Kana, Keller, Minshew & Just, 2007). Some influential theorists have called the very existence of cognitive inhibition into question (MacLeod, 2007a). This is a case where brain-imaging research holds the promise to be able to shed light into the covert nature of inhibition, with potentially immeasurable impact on understanding and ameliorating conditions such as ADHD, addiction, and frontal lobe injuries. A critical review of the literature shows that inhibitory control is subserved by a network of brain regions including as key components the inferior frontal cortex, the pre-supplementary motor area, and the sub-thalamic nucleus. It is argued that inhibitory control makes use of basic cognitive processes such as internalized speech. A common inhibitory mechanism for motor, speech and thought acts is proposed. Practical applications of research on inhibitory control are discussed such as brain plasticity exercises and electrical brain stimulation