In our daily lives, we experience a wide variety of sensations when touching or stroking objects with our fingers. These tactile sensations are generated when frictional stimuli on the skin surface are transmitted to the brain via the nervous system, activating specific brain regions. In recent years, there has been growing interest in elucidating this mechanism, and an increasing number of studies have investigated the relationship between tactile sensation and brain activity.

　Several techniques are available for measuring brain activity. Functional magnetic resonance imaging (fMRI) enables high-spatial-resolution imaging of changes in cerebral blood flow. Functional near-infrared spectroscopy (fNIRS) provides a relatively accessible means of measuring blood flow changes by irradiating the scalp with near-infrared light. Electroencephalography (EEG) allows real-time recording of the brain's electrical activity. Since each of these methods has distinct characteristics, it is important to select the most appropriate technique according to the research objective and to establish standardized experimental protocols for reliable data acquisition.

　However, when investigating dynamic tactile stimuli such as finger sliding friction, the choice of measurement method and data processing procedure has not yet been standardized across research groups, leaving challenges in terms of reproducibility and comparability of results.

　The present study therefore aims to establish a reliable and reproducible experimental methodology for measuring brain responses to finger sliding friction stimuli.