Dominant and subdominant hand exhibit different cortical activation patterns during tactile stimulation: An fNIRS study

Recently, only little is known about the cortical activity of tactile sensation for the dominant and subdominant hand. The objective of this study was to investigate the hemodynamic response of human's cortical brain to tactile sensation to compare the dominant and subdominant hand. Ten healthy adults, 25-35 ages, were enrolled. A 45 channel near-infrared spectroscopy system was used to measure brain responses and a solenoid resonance actuator was utilized to stimulate tactile sensation. The results showed that for the hemodynamic response to both hands on tactile stimulation, the corresponding primary sensory cortex and supplementary motor area were commonly activated, but the tactile stimuli of the subdominant hand induced broader areas of cortical activation than that of the dominant hand. Thus, broad brain areas, including the primary motor cortex and sensory association cortex, were activated by tactile stimulation in subdominant hand. These results suggest that there are differences in brain responses to tactile stimulation of the dominant and subdominant hand, which may reflect the importance of neural adaptability and efficiency for tactile sensation of the hand dominance.