Influence of Transcranial Direct Stimulation Current on Motor Learning of Young Adults

Overview

Motor learning occurs with structural and functional modifications in neural networks that meet a certain demand. The improvement of performance in diverse activities is a measure of learning, as well as the generalization and transference of this capacity. Transcranial direct current stimulation (tDCS) is a modulation technique of brain activity that modifies cortical excitability, causing changes in motor evoked potentials that influence motor learning. Modifications similar to the long-term potentiation, essential for learning processes, have also been described after applying tDCS. The primary motor cortex is the area of stimulation where there is more robust evidence in favor of increased motor learning. PURPOSE: to investigate the effects of anodic tDCS on the learning of sequential finger movements in young and healthy individuals.

Thirty-six young healthy individuals, right-handed, with no deficits that difficult the performance of the procedures will participate in the study. These individuals will be randomly divided into an experimental group that will perform the motor training of a sequential task of fingers simultaneously to the anodic tDCS on the contralateral motor cortex the trained hand and a control group that will perform the same training simultaneously the stimulation placebo (simulated in the same region of the experimental group). The training will consist of 8 blocks with 300 repetitions of sequential finger movements performed with only the right upper limb. The speed and accuracy of sequential movements will be used as a measure of performance. These measures will be performed prior to training, immediately after, 48 hours, 7 days, and 28 days after trained hand training (TH) for assessment of short and long term learning. In addition, performance evaluations (1) of the reverse-trained sequence in TH will be performed to evaluate the generalization; (2) of the trained sequence in left hand (non-trained) to evaluate the intermanual transfer; and (3) trained sequence in TH in double-task condition to evaluate automaticity. Appropriate statistical methods will be used to identify inter- and intra-group differences.