Brain activity during spoken word recognition in subacute aphasia

Abstract

The majority of task-based fMRI studies examining the neural mechanisms of aphasia recovery have been in the chronic phase, where people with aphasia typically employ both intact language areas, as well as recruiting additional areas within the left hemisphere and right hemisphere language homologues (Turkeltaub, Messing, Norise, & Hamilton, 2011). However, recovery from post-stroke aphasia (or language impairment) occurs in a number of stages, each underpinned by distinct neural mechanisms (Kiran, 2012, Saur et al., 2006). Compared to the acute stage, recovery in the subacute stage is less rapid and consists primarily of neural reorganisation leading to new alternative networks and changes in the efficacy of synaptic connections (Lazar & Antoniello, 2008). Recovery during this phase is thought to be associated with the normalisation over time of dysfunctional brain activity in areas remote or distant to the lesion (see Carrera and Tononi (2014) for a full review), perilesional restitution (Thompson and den Ouden, 2008, Warburton et al., 1999), or a functional transfer to the right hemisphere homologue (Saur et al., 2006)...