Deficit in automatic sound-change detection may underlie some music perception deficits after acute hemispheric stroke.

Music perception deficits following acute neurological damage are thought to be rare. By a newly devised test battery of music-perception skills, however, we were able to identify among a group of 12 patients with acute hemispheric stroke six patients with music perception deficits (amusia) while six others had no such deficits. In addition we recorded event-related brain potentials (ERPs) in a passive listening task with frequent standard and infrequent pitch deviants designed to elicit the mismatch negativity (MMN). The MMN in the patients with amusia was grossly reduced, while the non-amusic patients and control subjects had MMNs of equal size. These data show that amusia is quite common in unselected stroke patients. The MMN reduction suggests that amusia is related to unspecific automatic stimulus classification deficits in these patients.