Domain-general and domain-specific functional networks of Broca's area underlying language processing

Abstract

Introduction: Despite abundant research on the role of Broca's area in language processing, there is still no consensus on language specificity of this region and its connectivity network. Methods: The present study employed the meta-analytic connectivity modeling procedure to identify and compare domain-specific (language-specific) and domain-general (shared between language and other domains) functional connectivity patterns of three subdivisions within the broadly defined Broca's area: pars opercularis (IFGop), pars triangularis (IFGtri), and pars orbitalis (IFGorb) of the left inferior frontal gyrus. Results: The findings revealed a left-lateralized frontotemporal network for all regions of interest underlying domain-specific linguistic functions. The domain-general network, however, spanned frontoparietal regions that overlap with the multiple-demand network and subcortical regions spanning the thalamus and the basal ganglia. Conclusions: The findings suggest that language specificity of Broca's area emerges within a left-lateralized frontotemporal network, and that domain-general resources are garnered from frontoparietal and subcortical networks when required by task demands.