Improvement in precision grip force control with self-modulation of primary motor cortex during motor imagery.

Maria L Blefari,Roger Gassert,Marie-Claude Hepp-Reymond,Spyros Kollias,James Sulzer

doi:10.3389/fnbeh.2015.00018

Abstract

Motor imagery (MI) has shown effectiveness in enhancing motor performance. This may be due to the common neural mechanisms underlying MI and motor execution (ME). The main region of the ME network, the primary motor cortex (M1), has been consistently linked to motor performance. However, the activation of M1 during motor imagery is controversial, which may account for inconsistent rehabilitation therapy outcomes using MI. Here, we examined the relationship between contralateral M1 (cM1) activation during MI and changes in sensorimotor performance. To aid cM1 activity modulation during MI, we used real-time fMRI neurofeedback-guided MI based on cM1 hand area blood oxygen level dependent (BOLD) signal in healthy subjects, performing kinesthetic MI of pinching. We used multiple regression analysis to examine the correlation between cM1 BOLD signal and changes in motor performance during an isometric pinching task of those subjects who were able to activate cM1 during motor imagery. Activities in premotor and parietal regions were used as covariates. We found that cM1 activity was positively correlated to improvements in accuracy as well as overall performance improvements, whereas other regions in the sensorimotor network were not. The association between cM1 activation during MI with performance changes indicates that subjects with stronger cM1 activation during MI may benefit more from MI training, with implications toward targeted neurotherapy.

Highlights

Motor imagery (MI) is a cognitive process in which individuals internally simulate a movement or action as being performed by themselves, but without any overt movement
We aim to identify the role of contralateral primary motor cortex activity that may potentiate beneficial effects of MI on motor performance
RFX general linear model (GLM) GROUP ANALYSIS In a voxel-wise analysis, we investigated whether other brain regions were activated during the neurofeedback-guided motor imagery as a measure of specificity

Summary

Introduction

Motor imagery (MI) is a cognitive process in which individuals internally simulate a movement or action as being performed by themselves, but without any overt movement. MI is used in learning motor tasks, especially in sports, to complement physical training or to improve motor performance (Feltz and Landers, 1983; Alkadhi et al, 2005; Schuster et al, 2011 as review). MI may prove valuable in situations where motor execution is impaired or abolished due to neurological disease, its effect in neurorehabilitation has yielded mixed results (Malouin and Richards, 2013). This inconsistency is likely due to an incomplete understanding of the neural mechanisms underlying MI-based therapy, and growing evidence that the neurological disorder itself may interfere with MI ability (for review, see Di Rienzo et al, 2014). We aim to identify the role of contralateral primary motor cortex activity that may potentiate beneficial effects of MI on motor performance

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