Background An aphasia treatment was designed to shift laterality from the left to right lateral frontal lobe during word production by initiating word-finding trials with complex left-hand movements. Previous findings indicated successful relateralization. Objective The current study was designed to ascertain whether the shift was attributable to the left-hand movement. Methods Using stratified random sampling, 14 subjects were equally divided between Intention (IT) and Control (CT) treatments. CT was identical to IT, except with no left-hand movements. Both treatments trained picture naming (phases 1 and 2) and category-member generation (phase 3), each phase lasting 10 sessions. Functional magnetic resonance imaging of category member generation occurred at pretreatment, posttreatment, and 3-month follow-up. Results IT shifted lateral frontal activity rightward compared with pretreatment both at posttreatment (t = -2.602, df = 6, P < .05) and 3-month follow-up (t = -2.332, df = 5, P < .05), but CT did not. IT and CT yielded similar changes for all picture-naming and category probes. However, IT patients showed gains for untrained category (t = 3.33, df = 6, P < .01) and picture-naming probes (t = 3.77, df = 5, P < .01), but CT patients did not. Conclusions The rightward shift in lateral frontal activity for IT was because of the left-hand movements. IT evoked greater generalization than CT.
Keywords: aphasia; fMRI; magnetic resonance imaging; neuronal plasticity; rehabilitation; rehabilitation of speech and language disorders.
© The Author(s) 2014.