Hand Shape Familiarity Affects Guitarists' Perception of Sonic Congruence

Musical performance depends on the anticipation of the perceptual consequences of motor behavior. Altered auditory feedback (AAF) has previously been used to investigate auditory-motor coupling but studies to date have predominantly used MIDI piano in experimental tasks. In the present study, we extend the AAF paradigm to the guitar, which differs from the piano both motorically and in its pitch-to-place mapping, allowing further investigation into the nature of this coupling. Guitarists played chords on a MIDI guitar in response to tablature diagrams. In half of the trials, one of the notes in the heard chord was artificially altered. Participants judged whether the feedback was altered or not, responding as quickly and accurately as possible by pressing one of two buttons on a footswitch. Participants ranked the familiarity of the chord shapes and the hand shapes of the stimuli. Judgement of sonic congruence was faster when the chord and hand shape were familiar, and when feedback was congruent, though there was no interaction between these factors. Our findings suggest that guitarists’ auditory-motor coupling is heterogenous with respect to their technique, and that perception-action coupling operates at the abstract level of the gesture. We discuss implications of these findings with regard to forward models and embodiment.