Effects of signal duration on vibrotactile intensity discrimination

Abstract

Vibrotactile intensity DLs were measured by the continuous pedestal and gated pedestal methods. In both cases, the relative DL decreased as a function of the sensation level of the stimulus and the results, in most cases, could be described as a near miss to Weber’s law. DLs measured by the continuous pedestal method were found to decrease substantially as a function of increases in stimulus duration over a range of 12 to 1000 ms and the results could be described by a temporal summation function derived from Zwislocki’s theory of temporal summation [J. J. Zwislocki, J. Acoust. Soc. Am. 32, 1046–1060 (1960)]. In contrast, DLs measured by the gated pedestal method were only slightly affected by changes in stimulus duration. These findings are consistent with the hypothesis that, at suprathreshold levels of stimulation, the effects of temporal summation tend to be cancelled by the effects of adaptation.