How the degree of instrumental practice in music increases perceptual sensitivity.

Literature has shown that playing a musical instrument is associated with the formation of multimodal audio visuomotor representations that are strongly instrument-specific. Here, we investigated the effect of increased motor practice on perceptual sensitivity in 32 professional musicians of comparable expertise but with different amounts of instrumental practice with piano (10,000 vs. 3000 estimated hours). Stimuli consisted of images of pianists' hands and piano arpeggio sounds. In half of the cases, the piano fingering and piano sounds were congruent, while they were incongruent in the other cases. ERPs were recorded from 128 sites while musicians performed a congruent vs. incongruent discrimination task. A fronto-central error-related negativity (ERN), mainly generated within the anterior cingulate cortex, was observed in response to incongruent videos only in pianists. Non-pianist musicians were able to carry out the task (with a worse performance) but exhibited a smaller response-related N400 to incongruent stimuli. Source reconstruction applied to ERP responses to incongruent stimuli indicated a less automatic mechanism for detecting sensory-motor deviance and a greater emphasis on visual rather than on acoustic features in non-pianists. Overall the data suggest a profound difference between the two populations of musicians and advise against considering "expert" populations to include those that undertook only a few weeks/months of training in a new discipline.