Is time reproduction sensitive to sensory modalities?

To examine the influence of sensory modality on time reproduction, we investigated the location of the indifference interval in the visual and auditory modalities with two ranges of duration (1-5.5 s and 1-10 s). Results showed that in the visual modality, the location of the indifference interval did not shift as a function of duration range and over trials: It was located around 3 s. In the auditory modality, it varied with the duration range: It was also located around 3 s for the first trials and progressively shifted to the mean of both tested ranges. A common mechanism was thus implied in the two modalities, intervals below and above 3 s being differentially processed but with auditory durations, a dynamic process superimposed to this supramodal mechanism. These explanations based on the differential properties of sensory memories and on learning mechanisms taking place during the task are discussed in light of time perception models.