Discrimination is not impaired when more cortical space between two electro-tactile markers increases perceived duration.

The purpose of the present study was to examine how duration processing is affected by space between two electro-tactile stimuli marking inter-stimulus time intervals. The results of two experiments, where the method of constant stimuli was used, indicated that discrimination remained at the same level when delivering two markers to different fingers (of the same hand) resulted in longer perceived duration than delivering them to the same finger. Indeed, in Experiment 1, intervals were overestimated while discrimination remained at the same level when the leading and tailing markers were delivered to the index and ring fingers, respectively, compared with when both markers were delivered to the index finger. In Experiment 2, while there were individual differences in spatial effect on perceived duration when the leading and tailing markers were delivered to the middle and little fingers, respectively, discrimination remained at the same level even with participants overestimating intervals. This indicates that variability in duration processing is constant within the same cortical hemisphere when more space between two stimuli marking time results in longer perceived duration.