Biology subjects

Shiotani, S.

Publications and source records attributed to Shiotani, S..

3 recordsLinked to original sources

bioRxiv2024

A specialized inhibitory function sharpens somatosensory hand representation and enhances the production and perception of fast multifinger movements in pianists

Accurate control of fast, coordinated movements across multiple body parts characterizes experts skills, such as playing musical instruments. While performing such skillful movements, the somatosensory system is challenged to successively and in parallel process a large amount of somatosensory information originating from different body parts within a short period. Over decades, it has been posited that the cortical representations of distinct body parts are more isolated from each other in trained than untrained individuals. Several recent studies, however, have re-examined and failed to replicate it. Here, we provide compelling evidence that expert pianists possess a unique inhibitory function that isolates the somatosensory processing of different body parts in the somatosensory cortex (S1). A behavioural experiment demonstrated a superior ability to perceive fast multifinger movements in pianists than musically untrained individuals, suggesting the specialized neural process of somatosensory information originating from multiple fingers within a short period in pianists. A series of neurophysiological experiments demonstrated that pianists have a unique inhibitory function in the S1, which was activated by weak electrical stimulation to the ulnar nerve. This stimulation also increased the representational distance between fingers, which was assessed based on cortical activation patterns elicited by the passive finger movements. This indicates the strengthened independence of the individual finger representation in the somatosensory processes specifically in pianists. This stimulation also augmented both the perception and execution of the fast and complex multifinger sequential movements. In nonmusicians, neither the inhibitory effects on the somatosensory process nor enhancement of the perception of multifinger movements was induced by this stimulation. Together, these findings provide the first evidence of the experience-dependent plasticity of inhibition of the somatosensory system, which highlights its pivotal role in the isolated somatosensory processing of multiple body parts in trained individuals and enables them to control fast and complex multifinger movements.

neuroscience↗

bioRxiv2023

Robustness and adaptability of sensorimotor skills in expert piano performance

Skillful execution of sequential actions requires the delicate balance of sensorimotor control, encompassing both robustness and adaptability. Previous studies have characterized behavioral and electrophysiological responses to sensory perturbation during performance of sequential movements such as speech and singing. However, it remains unknown whether and in what manner both motor and neural responses, triggered by sensory perturbation, undergo plastic adaptation as a consequence of extensive sensorimotor experience. Here, we addressed this question by comparing effects of transiently delayed tone production on the spatiotemporal patterns of the subsequent motor actions and event-related potentials (ERPs) during fast and accurate piano performance between expert pianists and musically-untrained individuals (non-musicians). Following the delayed tone production, the inter-keystroke interval was abnormally prolonged in non-musicians but not in pianists. By contrast, the keystroke velocity following the tone delay was increased only in the pianists. A regression model further demonstrated that the change in the inter-keystroke interval following the perturbation covaried with the ERPs of the N180 and P300 components particularly at the frontal and parietal regions. In contrast, the alteration in the keystroke velocity was associated with the P300 component of the temporal region ipsilateral to the moving hand, which suggests enhancement of auditory but not somatosensory feedback gain following auditory perturbation. Together, these findings suggest that distinct neural mechanisms underlie robust and adaptive sensorimotor skills individuals with different levels of proficiency.

neuroscience↗

bioRxiv2023

Brain network flexibility as a predictor of skilled musical performance

Interactions between the body and the environment are dynamically modulated by upcoming sensory information and motor execution. To adapt to this behavioral state-shift, brain activity must also be flexible and possess a large repertoire of brain networks so as to switch them flexibly. Recently, flexible internal brain communications, i.e., brain network flexibility, have come to be recognized as playing a vital role in integrating various sensorimotor information. Therefore, brain network flexibility may be one of the key factors that define sensorimotor skill. However, little is known about how flexible communications within a brain characterizes inter-individual variation of sensorimotor skill and trial-by-trial variability within individuals. To address this, we recruited highly skilled musical performers (i.e. brass instrumentalists) and used a novel approach that combined multichannel-scalp electroencephalography (EEG) recordings, behavioral measurements of musical performance, and mathematical approaches to extract brain network flexibility. We found that brain network flexibility immediately before initiating the performance predicted inter-individual differences in the precision of tone timbre (as represented by spectral centroid of the sound), but not trial-by-trial variability at the individual level. Furthermore, brain network flexibility in broader cortical regions, rather than specific local cortical regions, predicted skilled musical performance, indicating that whole-cortical fluctuations determine individual skill. Our results provide novel evidence that brain network flexibility during movement preparation plays an important role in skilled sensorimotor performance and our findings have potentials for designing a new approach to predict an individuals skill from neural dynamics and a new intervention tool to facilitate physical education.

neuroscience↗