Right lateral prefrontal cortex—specificity for inhibition or strategy use?

This scientific commentary refers to ‘Verbal suppression and strategy use: a role for the right lateral prefrontal cortex?’, by Robinson et al. (doi:10.1093/brain/awv003). The specific functions of prefrontal cortex (PFC) subregions remain a matter of controversy. There is an urgent need to resolve this debate, in particular to improve outcomes for patients with behavioural problems caused by PFC dysfunction. One of the most prevalent behavioural symptoms is disinhibition, i.e. the inability to suppress a response to a prepotent stimulus, which can cause great distress to patients and their families. Functional imaging and animal lesion models have long been used to study disinhibition but there is still no consensus as to how different PFC subregions contribute to this deficit. At the same time, there are limited human lesion studies on disinhibition and few attempts have been made to translate imaging and animal findings back to patients.In the current issue of Brain , Robinson and colleagues address this issue by investigating the specificity of PFC subregions for verbal initiation, suppression and strategy use in a large cohort ( n = 90) of lesion patients (Robinson et al. , 2015). More specifically, the authors contrast the performance of frontal ( n = 60) and posterior ( n = 30) patients on the Hayling Sentence Completion Test (Burgess and Shallice, 1996). The Hayling test consists of two parts, with the first section asking participants to complete sentences with appropriate words (for example: ‘He posted the letter without a …’ could be completed by saying ‘stamp’), …