The Effects of Mirror Feedback during Target Directed Movements on Ipsilateral Corticospinal Excitability

Frontiers in Human Neuroscience

Eugene Tunik⁴  Sergei V. Adamovich⁶  Mathew Yarossi⁶  Thushini Manuweera⁶ 

[1] Department of Bioengineering, Northeastern UniversityBoston, MA, USA;Department of Biology, Northeastern UniversityBoston, MA, USA;Department of Biomedical Engineering, New Jersey Institute of TechnologyNewark, NJ, USA;Department of Electrical and Computer Engineering, Northeastern UniversityBoston, MA, USA;Department of Physical Therapy, Movement, and Rehabilitation Sciences, Northeastern UniversityBoston, MA, USA;Department of Rehabilitation and Movement Sciences, Rutgers Biomedical Health SciencesNewark, NJ, USA;Graduate School of Biomedical Sciences, Rutgers Biomedical and Health SciencesNewark, NJ, USA;

关键词: TMS;    mirror feedback;    target;    action observation;    virtual reality;   

DOI  :  10.3389/fnhum.2017.00242

来源: DOAJ

【 摘 要 】

Mirror visual feedback (MVF) training is a promising technique to promote activation in the lesioned hemisphere following stroke, and aid recovery. However, current outcomes of MVF training are mixed, in part, due to variability in the task undertaken during MVF. The present study investigated the hypothesis that movements directed toward visual targets may enhance MVF modulation of motor cortex (M1) excitability ipsilateral to the trained hand compared to movements without visual targets. Ten healthy subjects participated in a 2 × 2 factorial design in which feedback (veridical, mirror) and presence of a visual target (target present, target absent) for a right index-finger flexion task were systematically manipulated in a virtual environment. To measure M1 excitability, transcranial magnetic stimulation (TMS) was applied to the hemisphere ipsilateral to the trained hand to elicit motor evoked potentials (MEPs) in the untrained first dorsal interosseous (FDI) and abductor digiti minimi (ADM) muscles at rest prior to and following each of four 2-min blocks of 30 movements (B1–B4). Targeted movement kinematics without visual feedback was measured before and after training to assess learning and transfer. FDI MEPs were decreased in B1 and B2 when movements were made with veridical feedback and visual targets were absent. FDI MEPs were decreased in B2 and B3 when movements were made with mirror feedback and visual targets were absent. FDI MEPs were increased in B3 when movements were made with mirror feedback and visual targets were present. Significant MEP changes were not present for the uninvolved ADM, suggesting a task-specific effect. Analysis of kinematics revealed learning occurred in visual target-directed conditions, but transfer was not sensitive to mirror feedback. Results are discussed with respect to current theoretical mechanisms underlying MVF-induced changes in ipsilateral excitability.

【 授权许可】

Unknown