Multisensory Duration Reproduction in the Supra-second Range

Didem Alaşhan, Reşit Canbeyli & İnci Ayhan
  • Internal clock model assumes that different sensory modalities use the same mechanism to judge temporal intervals. Here, in blocked trials, we presented participants with an auditory and a visual noise stimuli in 5 conditions - pure visual, pure audio, audio-visual simultaneous, audio-visual sequential and visual-audio sequential, for 7 durations, equally spaced on a logarithmic scale between 2-10s and asked to reproduce their perceived durations. Results showed that subjective durations of sequentially presented bimodal stimuli are relatively shorter than those of unimodal or simultaneously presented bimodal stimuli. We also demonstrated that this temporal compression effect cannot be explained by the changes in perceived onsets-offsets of stimuli of different types, implying a genuine duration effect, which we suggest, is caused by an unpredictability introduced by a shift in rather different modality-specific timing mechanisms in the supra-second range.