Interaction between auditory and motor systems in sensorimotor synchronization

Abstract

Sensorimotor synchronization is defined as the synchronization of rhythmic actions with external stimuli and occurs naturally in dancing or when we tap our fingers to the beat of music. It has been suggested that this phenomenon is possible because of the presence of particular neural links between both motor and auditory systems (audio-motor coupling), and that they do not occur, for example, between the motor and the visual systems (Zatorre et al., 2007). In this work, we provide evidence of the audio-motor coupling presence in a sensorimotor synchronization task, specifically in a finger tapping paradigm (synchronization of finger movements with external stimuli). We conducted a finger tapping experiment with an auditory metronome in which 44 musicians participated. We measured tapping force under two sensory feedback conditions (with and without additional auditory feedback) and under two attentional levels. The results show that the duration of the contact between the finger and the sensor is significantly shorter in conditions with additional auditory feedback, suggesting a capture effect of the auditory modality over the motor control; such results have been considered as a signature of the audio-motor coupling (Chen et al., 2006). On the other hand, the aforementioned results were shown to be independent of the attention level, which indicate that the audio-motor coupling could operate at a pre-attentional level.