Somatotopic representation of tactile duration: evidence from tactile duration aftereffect

Abstract

Accurate perception of sub-second tactile duration is critical for successful human-machine interaction and human daily life. However, it remains debated where the cortical processing of tactile duration takes place. Previous studies have shown that prolonged adaptation to a relatively long or short auditory or visual stimulus leads to a repulsive duration aftereffect such that the durations of subsequent test stimuli within a certain range appear to be contracted or expanded. Here, we demonstrated a robust repulsive tactile duration aftereffect with the method of single stimuli, where participants determined whether the duration of the test stimulus was shorter or longer than the internal mean formed before the adaptation (Experiment 1A). The tactile duration aftereffect was also observed when participants reproduced the duration of the test stimulus by holding down a button press (Experiment 1B). Importantly, the observed tactile duration aftereffect was tuned around the adapting duration (Experiment 1C). Moreover, the effect was confined in the adapted sensory modality (Experiment 2) and the enacted fingers within a somatotopic framework (Experiment 3). These findings suggest the early somatosensory areas with the topographic organization of hands play an essential role in sub-second tactile duration perception.

Keywords: adaptation aftereffect; somatotopic distance; somatotopic processing; tactile duration.