Cross-Modal Audiovisual Modulation of Corticospinal Motor Synergies in Professional Piano Players: A TMS Study during Motor Imagery.

Simone Rossi,Domenico Prattichizzo,Marco Emanuele,Luciano Fadiga,Monica Ulivelli,Emiliano Santarnecchi,Daniela Perani,Danilo Spada,Alessandro Rossi

doi:10.1155/2019/1328453

Abstract

Transcranial magnetic stimulation was used to investigate corticospinal output changes in 10 professional piano players during motor imagery of triad chords in C major to be “mentally” performed with three fingers of the right hand (thumb, index, and little finger). Five triads were employed in the task; each composed by a stable 3rd interval (C4-E4) and a varying third note that could generate a 5th (G4), a 6th (A4), a 7th (B4), a 9th (D5), or a 10th (E5) interval. The 10th interval chord was thought to be impossible in actual execution for biomechanical reasons, as long as the thumb and the index finger remained fixed on the 3rd interval. Chords could be listened from loudspeakers, read on a staff, or listened and read at the same time while performing the imagery task. The corticospinal output progressively increased along with task demands in terms of mental representation of hand extension. The effects of audio, visual, or audiovisual musical stimuli were generally similar, unless motor imagery of kinetically impossible triads was required. A specific three-effector motor synergy was detected, governing the representation of the progressive mental extension of the hand. Results demonstrate that corticospinal facilitation in professional piano players can be modulated according to the motor plan, even if simply “dispatched” without actual execution. Moreover, specific muscle synergies, usually encoded in the motor cortex, emerge along the cross-modal elaboration of musical stimuli and in motor imagery of musical performances.

Highlights

Since the musculoskeletal system is highly redundant, the motor system is thought to employ a restricted set of modular commands, or synergies, to accomplish both automatic and goal-directed actions [1]
A trend toward significance was found for the comparison of Flexor Digitorum Superficialis (FDS) vs. Abductor Digiti Minimi (ADM) (p = 0 090) (Figure 2)
Corticospinal excitability assessed during motor imagery of chords was greater at the Abductor Pollicis Brevis (APB) compared to the Extensor Communis Digitorum (ECD) and FDS and at the ADM compared to the ECD

Summary

Introduction

Since the musculoskeletal system is highly redundant, the motor system is thought to employ a restricted set of modular commands, or synergies, to accomplish both automatic and goal-directed actions [1]. Using principal component analysis (PCA), it has been demonstrated that few principal components account for a great amount of variance in the hand’s degrees of freedom (i.e., joint angles) during maintenance of static hand postures [2] This strategy aims to reduce the dimensionality of motor commands with valuable computational advantages. In a study combining kinematic, electromyographic and neuroimaging recordings, synergies involved in several hand postures were successfully predicted by neural activation pattern in the motor cortex [7]. These findings suggest that neural assemblies in the motor cortex are connected in a complex way to the periphery and might contribute to arm movements that require the coordinated activation of some muscles and relaxation of others. The control of movements in the motor cortex might be organized in terms of behaviorally useful actions

Methods

Results

Conclusion