Attenuating the Effect of Sensory Modality on Time Perception

In psychophysics domain, various factors have been studied as the main account of the time contraction after stimulus repetition and the time expansion after a novel stimulus; however, there is no clear explanation about the amount of involvement of temporal and non-temporal features. In this study, 48 sub-jects participated in 3 experiments in which the purer role of temporal properties of stimului were examined. Data were provided by a tem-poral oddball paradigm and the analysis was implemented by repeated measures analysis of variance in experiments 1 and 3. In experiment 2, a psychometric function was used to deter-mine the modified estimations in temporal pro-cessing system. Findings showed that despite removing the non-temporal change in expe-riment 1, the temporal change between repea-ted/non-repeated stimuli can produce time con-traction and dilation respectively. The result was only for the auditory system. In experi-ment 2, an efficient threshold for temporal oddball was suggested. Using the updated threshold, experiment 3 revealed concordant repeated/non-repeated effects on time percep-tion in both modalities.