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

Abstract

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