Common Neural Substrates for Inhibition of Spoken and Manual Responses

Cereb Cortex. 2008 Aug;18(8):1923-32. doi: 10.1093/cercor/bhm220. Epub 2008 Jan 31.

Abstract

The inhibition of speech acts is a critical aspect of human executive control over thought and action, but its neural underpinnings are poorly understood. Using functional magnetic resonance imaging and the stop-signal paradigm, we examined the neural correlates of speech control in comparison to manual motor control. Initiation of a verbal response activated left inferior frontal cortex (IFC: Broca's area). Successful inhibition of speech (naming of letters or pseudowords) engaged a region of right IFC (including pars opercularis and anterior insular cortex) as well as presupplementary motor area (pre-SMA); these regions were also activated by successful inhibition of a hand response (i.e., a button press). Moreover, the speed with which subjects inhibited their responses, stop-signal reaction time, was significantly correlated between speech and manual inhibition tasks. These findings suggest a functional dissociation of left and right IFC in initiating versus inhibiting vocal responses, and that manual responses and speech acts share a common inhibitory mechanism localized in the right IFC and pre-SMA.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Brain Mapping / methods
  • Cerebral Cortex / physiology*
  • Female
  • Humans
  • Inhibition, Psychological*
  • Male
  • Motor Skills / physiology*
  • Psychomotor Performance / physiology
  • Reaction Time / physiology
  • Speech / physiology*