★ We pitch shifted vocalizations of congenital amusics and controls in real time. ★ Half of amusics showed a normal pitch shift response, half showed none. ★ Pitch shift response occurred to small and large shifts. ★ Vocal pitch matching accuracy predicted size and presence of pitch shift response. ★ Results suggest a dissociation between pitch perception and production abilities.
We tested whether congenital amusics, who exhibit pitch perception deficits, nevertheless adjust the pitch of their voice in response to a sudden pitch shift applied to vocal feedback. Nine amusics and matched controls imitated their own previously-recorded speech or singing, while the online feedback they received was shifted mid-utterance by 25 or 200 cents. While a few amusics failed to show pitch-shift effects, a majority showed a pitch-shift response and nearly half showed a normal response to both large and small shifts, with similar magnitudes and response times as controls. The size and presence of the shift response to small shifts were significantly predicted by participants’ vocal pitch matching accuracy, rather than their ability to perceive small pitch changes. The observed dissociation between the ability to consciously perceive small pitch changes and to produce and monitor vocal pitch provides evidence for a dual-route model of pitch processing in the brain.