Contextual Effects on Duration Perception Are Modality-Specific

The perception of magnitude, crucial for a mental representation of the physical world, is often subject to significant biases. Many of these biases are similar across sensory modalities, implying a generalized perception of magnitude. At the same time, some physical magnitudes might have a dedicated modality-specific calibration mechanism to enhance perceptual sensitivity. We examined this question of generalized versus modality-specific processes testing between- and within-modalities' contextual effects on the perception of magnitude. In a constant stimuli procedure, a central standard was embedded in shorter and longer contextual standards. These contextual standards were sampled in either a relatively wider or narrower range of durations. Participants were asked to determine which of the two consecutive durations was longer. Better perceptual sensitivity was found for narrower contexts, with stronger effects in trials in which the standard was presented first. Interestingly, narrower context enhanced sensitivity for standards within the same modality but had no effect on standards of another modality. A unidirectional transfer of contextual effects was observed under certain conditions from auditory, the dominant modality in performing temporal judgments, to vision. These results suggest that the perceptual system appears to develop modality-specific calibration mechanisms, most likely, to enhance perceptual sensitivity and maintain sensory specialization.