Imaging the language network: functional neuroanatomy, acquired aphasia, and recovery

What is the functional architecture of the language network? How is it impacted by damage to its various nodes and connections? And when it is damaged, how can it reorganize to support recovery of language function? To address these questions, we have carried out a series of multimodal neuroimaging studies in individuals with acquired language deficits of diverse etiologies–stroke, neurodegenerative disease, and resective surgery–as well as neurologically normal volunteers. Our findings, along with those of others, reveal a complex, variegated language network in which numerous distinct regions and tracts in the temporal, frontal and parietal lobes play distinct functional roles. Yet the network is strikingly resilient to most patterns of damage, indicating that in many cases, functional specialization is graded rather than absolute. Our findings suggest that recovery from aphasia depends primarily on reconfiguration of spared language regions, rather than macroscopic reorganization of the whole system.