Enhanced somatosensory inhibition sharpens hand representation and sensorimotor skills in pianists.

Abstract

Dexterous motor skills, like those needed for playing musical instruments and sports, require the somatosensory system to accurately and rapidly process somatosensory information from multiple body parts. This is challenging due to the convergence of afferent inputs from different body parts into a single neuron and the overlapping representation of neighboring body parts in the somatosensory cortices. How do trained individuals, such as pianists and athletes, manage this? Here, a series of five experiments with pianists and nonmusicians (female and male) shows that pianists have enhanced inhibitory function in the somatosensory system, which isolates the processing of somatosensory afferent inputs from each finger. This inhibitory function was assessed using a paired-pulse paradigm of somatosensory evoked potentials in Electroencephalography (EEG), which measures the suppressive effect of a first stimulus (i.e., conditioning stimulus) on the response to a subsequent second stimulus. We found that pianists and nonmusicians showed an inhibitory response to the sequential stimuli to the peripheral somatosensory nerve at the wrist when the conditioning stimulus was intense. However, only pianists exhibited an inhibitory response to a weak conditioning stimulus, indicating enhanced inhibitory function in pianists. Additionally, the conditioning stimulus increased the information content segregating individual fingers represented in the cortical activity evoked by passive finger movements and improved the perception of fast multi-finger sequential movements, specifically for pianists. Our findings provide the first evidence for experience-dependent plasticity in somatosensory inhibitory function and highlight its role in the expert motor performance of pianists.Significant statement Fine motor skills, such as playing musical instruments, rely on the somatosensory system to process somatosensory information from multiple body parts. How does the somatosensory system process inputs from different body parts separately and with less interference? This study discovered enhanced inhibitory function in the somatosensory system of expert pianists, which contributes to isolating finger representation in the somatosensory processing and thereby improve the perception and execution of fast and complex multifinger movements. The present findings demonstrate that extensive musical training strengthens inhibitory processing in the somatosensory system, which underlies pianists' remarkable finger dexterity.