Activity in superior parietal cortex during training by observation predicts asymmetric learning levels across hands.

Ori Ossmy,Roy Mukamel

doi:10.1038/srep32133

Abstract

A dominant concept in motor cognition associates action observation with motor control. Previous studies have shown that passive action observation can result in significant performance gains in humans. Nevertheless, it is unclear whether the neural mechanism subserving such learning codes abstract aspects of the action (e.g. goal) or low level aspects such as effector identity. Eighteen healthy subjects learned to perform sequences of finger movements by passively observing right or left hand performing the same sequences in egocentric view. Using functional magnetic resonance imaging we show that during passive observation, activity in the superior parietal lobule (SPL) contralateral to the identity of the observed hand (right\\left), predicts subsequent performance gains in individual subjects. Behaviorally, left hand observation resulted in positively correlated performance gains of the two hands. Conversely right hand observation yielded negative correlation - individuals with high performance gains in one hand exhibited low gains in the other. Such behavioral asymmetry is reflected by activity in contralateral SPL during short-term training in the absence of overt physical practice and demonstrates the role of observed hand identity in learning. These results shed new light on the coding level in SPL and have implications for optimizing motor skill learning.

Highlights

Heyes and Ray argue that action observation engages similar learning processes as overt physical practice, and depends on the identity of the observed effector[31,35]
This theory was supported by a series of empirical studies in which participants performed a serial reaction time (SRT) task, and performance was facilitated only when subjects used the same effector as the one they observed during passive training[28,36,37,38]
We examined whether functional magnetic resonance imaging (fMRI) activity level in the same regions of interest (ROI) during ‘Obs-RH’ training period corresponds to subsequent left or right hand performance gains

Summary

Introduction

Heyes and Ray argue that action observation engages similar learning processes as overt physical practice, and depends on the identity of the observed effector[31,35] This theory was supported by a series of empirical studies in which participants performed a serial reaction time (SRT) task, and performance was facilitated only when subjects used the same effector as the one they observed during passive training[28,36,37,38]. A study by Frey and Gerry showed that activity in the right intraparietal sulcus predicts learning levels following training by observation They used a bimanual sequential task and were not able to outline the role of hand identity (right/left) in the perceptual-motor learning process[42]. To this end we acquired whole-brain functional magnetic resonance imaging (fMRI) data while healthy subjects were engaged in a short-term unimanual learning-by-observation task

Methods

Results

Conclusion