Transcranial direct current stimulation over the posterior parietal cortex improves visuomotor performance and proprioception in the lower extremities

Abstract

The purpose of this study was to examine whether anodal transcranial direct current stimulation (a-tDCS) over the posterior parietal cortex (PPC) could affect visuomotor performance and proprioception in the lower extremities. We evaluated visuomotor performance in 15 healthy volunteers using a visuomotor control task by plantar dorsiflexion of the ankle joint, and calculated the absolute difference between the target and measured angle. In addition, we evaluated proprioception using a joint position matching task. During the task, the subject reproduced the ankle joint plantar dorsiflexion angle presented by the examiner. We calculated the absolute difference between the presented and measured angles (absolute error) and the variation of measured angles (variable error). Simultaneously, a-tDCS (1.5 mA, 15 min) or sham stimulation was applied to the right PPC. We observed that the absolute error of the visuomotor control task and the variable error of the joint position matching task significantly decreased after a-tDCS. However, the absolute error of the joint position matching task was not affected. This study suggests that a-tDCS over the PPC improves visuomotor performance and reduces the variable error in the joint position matching task.

Effects of transcranial electrical stimulation of the right posterior parietal cortex on physical control responses

“…It is also possible that the neuronal ring rate was increased but did not signi cantly affect the postural control response. Anodal tDCS to the PPC did not signi cantly increase the neural ring rate, suggesting that there was no signi cant change in absolute error in the lower limb joint position matching task [35]. These considerations are also applicable to the tRNS results.…”

“…It has been reported that the tDCS slightly increases the neural excitability of the brain regions receiving anodal stimulation [32], and the tRNS synchronizes the cellular ring of large populations by propagating from a single cell to neuronal cells at the population level through stochastic resonance mechanisms [33,34]. Previous research has shown that anodal tDCS and tRNS to the PPC can alter body performance such as tactile perception and joint position matching [13,35]. Although these tES techniques reportedly increased the excitability of the PPC region by adapting P4, this study did not induce changes in body control responses.…”

The Effects of Transcranial Direct Current Stimulation (tDCS) and Biofeedback on Proprioception and Functional Balance in Athletes with ACL-deficiency

“…They used visual biofeedback along with exercise training in patients with knee arthroscopy and suggested that information received through visual feedback could act as a sensory alternative to compensate for the proprioception of the injured limb in patients (39). Regarding the effect of tDCS, on the other hand, the previous studies have also demonstrated that it could have a positive role in the improvement of absolute error of proprioception in healthy young people (40)(41)(42) and patients with tendinitis (43). Stagg et al indicated that applying tDCS over left dorsolateral prefrontal cortex (DLPFC) caused increased activity of the sensorimotor cortex and decreased activity of the thalamus.…”