Improving Locomotor Learning With Brain Stimulation

Overview

The primary goal of this research was to assess the practicality and initial effectiveness of a motor imagery (MI) intervention combined with elements of action observation (AO), alongside active or sham transcranial direct current stimulation (tDCS) over the prefrontal cortex (PFC), on locomotor learning in healthy adults. Feasibility was determined by examining recruitment rates, participant engagement, and safety measures. The efficacy of the intervention was gauged by analyzing the time taken to complete tasks and changes in cerebral blood flow immediately after the intervention and one week later. The study was guided by three main hypotheses: (1) the intervention techniques would be well-received and safe for the participants; (2) compared to a control group, MI training would lead to better learning outcomes and retention of learning; (3) in comparison to the control and sham tDCS groups, active tDCS would result in superior learning outcomes and retention of learning.

The study implemented a double-blind, randomized, controlled trial design. Participants were tested three times over 7 days. After study enrollment, the participants were randomly assigned to one of three groups: MIActive (receiving active tDCS stimulation and participating in MI protocol), MISham (receiving sham tDCS stimulation and participating in MI protocol), and Control (receiving no stimulation and participating in an unrelated video-watching task) by a research member not associated with data collection. Allocation ratio was 1:1:1 and a block randomization approach was employed to maintain an equal distribution of participants across the three groups throughout the study. Study participants and assessors were blinded to assignment of active or sham tDCS. The independent variables were time (pre, post, and retention trials) and group (MIActive, MISham and Control), and the dependent variables were time to completion of a complex obstacle course and the amount of change in oxygenated hemoglobin (ΔO2Hb) during performance of that task.