The neural basis of aphasia rehabilitation: evidence from neuroimaging and neurostimulation.

This article is a selective review of functional imaging investigations and brain stimulation studies addressing the neural mechanisms of recovery of stroke-associated aphasia. The imaging results show that aphasia recovery is associated with a complex pattern of brain reorganisation, involving both ipsilateral and contralateral brain regions, which is modulated by lesion size and site, time post-onset, type of training, and language task. The information provided by the imaging investigations needs to be integrated with the results of brain stimulation studies, in order to specify the most effective protocols in term of modality, locus and timing of stimulation. Further studies, using multiple imaging and neuromodulation approaches, are required to reach sound conclusions about the potential usefulness of brain stimulation approaches as an adjunct to aphasia rehabilitation.