Changes in maps of language activity activation following melodic intonation therapy using magnetoencephalography: Two case studies

Two patients with chronic expressive aphasia underwent two blocks of melodic intonation therapy (MIT) each. Maps of language-specific neurophysiological activity were obtained prior to and after each MIT block during a covert action naming task using magnetoencephalography. Both patients exhibited increased left hemisphere activation after MIT. The patient who responded positively to therapy exhibited decreasing activation within areas of the right hemisphere homotopic to left hemisphere language areas compared to baseline after both blocks of MIT. In contrast, the patient who did not show improvement after therapy exhibited increasing activation in these areas of the right hemisphere after therapy. Results are consistent with hypotheses that melodic intonation therapy acts through promotion of left hemisphere activation.