ABSTRACT
Modality effects, specifically auditory and visual differences, can be used as a methodological tool to advance our understanding of normal timing. Application of interval timing paradigms that include a modality component to particular populations, such as healthy aged persons, can provide a window to the nature of the timing system, its function over the life span, and how it interacts with other cognitive and physiological variables. The modality effect also requires that the auditory and visual signals be compared to a common memory representation in order for a clock rate difference to manifest as a difference in perceived duration. Given the findings of different sensitivities to modality effects in young and aged populations, it is worthwhile to consider whether the existence of modality effects may prove a useful tool for examining the cognitive and neurophysiological bases of timing via studies of patient populations.
