Abstract
Accurate time perception underlies behavioural performance on many tasks: a pedestrian, attempting to cross the road, has to accurately estimate the time when an approaching car will cross his way. Perception of time is limited in accuracy due to internally generated temporal noise or uncertainty (ITU). ITU increases with time interval duration and as such increasingly interferes with behavioural performance. In the non-temporal domain (e.g. depth perception), studies have demonstrated that participants can use multiple cues (visual and tactile information) to improve performance by reducing sensory noise. Does this hold in the temporal domain? Participants completed a time interval reproduction task with a ready-set-go procedure. They received two visual stimuli (READY and SET), separated by one fixed target interval (TI). They were instructed to reproduce the TI after SET. After SET, at a fixed time interval before the correct time for the response (additional target interval: ATI), participants received an additional visual stimulus (AS). AS provided additional information about the correct time for the response. The degree of information depends on ATI duration (short/intermediarte/long); it decreases with increasing ATI duration due to increasing ITU. If participants use ATI, then precision in time interval reproduction should improve, in particular if the degree of information is high (short ATI). We tested whether participants (a) use only SET, (b) use AS and SET, or (c) use only AS for time interval reproduction. We computed expected precision in time interval reproduction for each hypothesis derived from baseline data (time interval reproduction without AS). Results show that participants use only AS. Thus, participants are able to extract information from SET and AS but fail to integrate the temporal information provided by both stimuli. We discuss implication of this failure to cue-integrate for modality-specific models of interval timing and perception of cause and consequence.
Meeting abstract presented at VSS 2012