Influence of a plantar perceptual learning task on brain activity: A fNIRS study

Abstract

[Purpose] The present study investigated the influence of a plantar perceptual learning task on brain activity using functional near-infrared spectroscopy. [Subjects] Ten healthy volunteers participated in this study. [Methods] Seated subjects performed a hardness discrimination task using the soles of their feet to discriminate between sponges with 5 different levels of hardness over a period of 10 days. Brain activity was measured using fNIRS during the discrimination task on the first and final days. A cap with optical fibers covered to cover the frontal and parietal lobes, as well as the temporal and occipital lobes. [Results] On Day 1 of the task, oxyhemoglobin (oxyHb) increased significantly in the prefrontal and premotor areas, and the parietal association and motor-speech areas. On Day 10 of the task, oxyHb levels increased significantly in the supplemental motor area, and the parietal association and motor-speech areas. [Conclusion] Activation of the brain was noted in the prefrontal, premotor, and supplemental motor areas as well as the parietal association and motor-speech areas during the plantar perceptual learning task.