Abstract
Repetitive exposure to relatively long or short sensory events has been shown to shorten or lengthen the perceived duration of a subsequent event, which is referred to as the repulsive duration aftereffect. Duration aftereffect in vision has received much attention, but little work has been done on the tactile duration aftereffect. Here, we used electroencephalography (EEG) to investigate how the tactile duration adaptation modulates the subsequent temporal encoding represented by the contingent negative variation (CNV). Participants compared the durations of the test vibrotactile stimulus (500 ms) and the visual disk (370, 450, 500, 550, or 630 ms) after adapting to short (200 ms) or long (800 ms) vibrotactile stimulus. The test vibrotactile stimuli were always presented on the left or right index fingertip, while the adapting vibrotactile stimuli could be presented on the same index fingertip (same location), or the middle fingertip of same hand (adjacent location), or the index fingertip of different hand (homologous location). Behavioral results showed that the aftereffect magnitudes, indexed by the arithmetic differences between the PSEs after short and long adaptations, were significantly larger than zero at the same and adjacent locations, but not at the homologous location. Importantly, the simultaneously recorded event-related potentials (ERPs) revealed that the test vibrotactile stimuli evoked clearly identifiable CNV components both in fronto-central and contralateral post-central scalp regions. However, only in the contralateral post-central scalp, the significant aftereffects (indexed by the arithmetic differences between the CNV amplitudes after long and short adaptations) were observed at the same and adjacent locations, but not at the homologous location. These findings suggest that topographic distances between the adapting and test fingers modulate the neural correlates of tactile duration aftereffect.