Dual-hemisphere transcranial direct current stimulation improves performance in a tactile spatial discrimination task

• Published in: Clinical neurophysiology Vol. 125; no. 8; pp. 1669 - 1674
• Main Authors: Fujimoto, Shuhei, Yamaguchi, Tomofumi, Otaka, Yohei, Kondo, Kunitsugu, Tanaka, Satoshi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ireland Ltd 01.08.2014
• Subjects: Adult; Analysis of Variance; Attention - physiology; Cortical plasticity; Cross-Over Studies; Double-Blind Method; Female; Functional Laterality - physiology; Humans; Inter-hemispheric inhibition (IHI); Male; Neurology; Neuronal Plasticity - physiology; Placebos; Reference Values; Somatosensory cortex; Somatosensory Cortex - physiology; Spatial Processing - physiology; Surveys and Questionnaires; Tactile; Touch - physiology; Touch Perception - physiology; Transcranial Direct Current Stimulation; Transcranial direct current stimulation (tDCS); Transcranial Magnetic Stimulation; Transcranial magnetic stimulation (TMS); Young Adult; Transcranial magnetic stimulation (TMS); Somatosensory cortex; Inter-hemispheric inhibition (IHI); Cortical plasticity; Tactile; Transcranial direct current stimulation (tDCS)
• ISSN: 1388-2457; 1872-8952; 1872-8952
• DOI: 10.1016/j.clinph.2013.12.100

•Dual-hemisphere transcranial direct stimulation (tDCS) is a novel and powerful strategy to improve human cognitive and motor function, but its effect on somatosensory function remains unknown.•We demonstrated that dual-hemisphere tDCS over the primary somatosensory cortex facilitates greater improvements for performance in a tactile discrimination task in healthy adults compared with uni-hemisphere and sham tDCS.•Dual-hemisphere tDCS might be useful to improve sensory function in patients with sensory dysfunctions. The aim of this study was to test the hypothesis that dual-hemisphere transcranial direct current stimulation (tDCS) over the primary somatosensory cortex (S1) could improve performance in a tactile spatial discriminative task, compared with uni-hemisphere or sham tDCS. Nine healthy adults participated in this double-blind, sham-controlled, and cross-over design study. The performance in a grating orientation task (GOT) in the right index finger was evaluated before, during, immediately after and 30min after the dual-hemisphere, uni-hemisphere (1mA, 20min), or sham tDCS (1mA, 30s) over S1. In the dual-hemisphere and sham conditions, anodal tDCS was applied over the left S1, and cathodal tDCS was applied over the right S1. In the uni-hemisphere condition, anodal tDCS was applied over the left S1, and cathodal tDCS was applied over the contralateral supraorbital front. The percentage of correct responses on the GOT during dual-hemisphere tDCS was significantly higher than that in the uni-hemisphere or sham tDCS conditions when the grating width was set to 0.75mm (all p<0.05). Dual-hemisphere tDCS over S1 improved performance in a tactile spatial discrimination task in healthy volunteers. Dual-hemisphere tDCS may be a useful strategy to improve sensory function in patients with sensory dysfunctions.