Transcranial Direct Current Stimulation to Augment Motor Imagery Training: A Systematic Review

Area of Science:

• Neuroscience
• Rehabilitation Science
• Motor Control

Background:

• Motor imagery training (MIT) is a key technique for motor learning and recovery.
• Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation method shown to enhance motor performance and neuroplasticity.
• Combining MIT and tDCS is being explored to optimize motor rehabilitation outcomes.

Purpose of the Study:

• To systematically review the evidence on the synergistic effects of combining MIT with tDCS.
• To focus specifically on the impact of this combined intervention on behavioral outcomes.
• To evaluate the efficacy of combined MIT and tDCS in both healthy and clinical populations.

Main Methods:

• Systematic literature review of 16 studies.
• Inclusion of 432 participants across healthy and clinical groups.
• Analysis of behavioral outcomes from combined MIT and tDCS interventions.

Main Results:

• Mixed results were observed due to heterogeneous study methods and populations.
• Anodal tDCS over the primary motor cortex may enhance MIT effects on motor performance in healthy individuals.
• Evidence for combined tDCS and MIT benefits in stroke patients using brain-computer interfaces (BCI) was less conclusive.

Conclusions:

• The combination of anodal tDCS and MIT shows potential for improving motor performance in healthy populations.
• Further research with larger sample sizes and standardized methodologies is needed to clarify benefits for clinical populations, particularly stroke patients in BCI protocols.
• Future studies should investigate both behavioral and neurophysiological outcomes, as well as long-term synergistic effects.