Singing to Speaking: Observations in Healthy Singers and Patients with Broca's Aphasia

The neural processes that underlie post-stroke language recovery, particularly in non-fluent aphasic patients, remain largely unknown and thus, have not been specifically targeted by aphasia therapies. Two possible pathways to recovery exist; one is through reorganization and recruitment of peri-lesional areas in the left, lesional hemisphere while the other involves the recruitment and possibly re-organization of homolog language-competent regions in the right. Because of its potential to engage/unmask language-capable brain regions in the unaffected right hemisphere, Melodic Intonation Therapy (MIT), has been proposed as a method to  facilitate language recovery in severely non-fluent aphasic patients, typically those with large left-hemisphere lesions encompassing the left frontal brain regions (including Broca’s region). Our behavioral and neuroimaging data of patients undergoing an intense form of MIT suggest significant improvements in measures of propositional speech (e.g., more meaningful words/min and increased phrase length) that are correlated with functional and structural imaging changes in a right-hemispheric fronto-temporal network. Furthermore, this intensive therapy leads to significant gains in speech production that can be maintained after therapy most likely due to structural remodeling of a right-hemisphere speech-production network. The efficacy of MIT is currently being tested in a randomized controlled clinical trial comparing MIT versus a similar control intervention (Speech Repetition Therapy) that does not contain two essential components of MIT, the melodic intonation and the rhythmic tapping with the left hand. Preliminary results of this trial will be presented (Supported by NIH 1RO1 DC008796).