Estimating distance and duration of travel: A possible shared mechanism

The perception of spatial extent and time duration may share several common properties. It is well established that a visually specified distance appears to be longer if there are more intervening points within that distance. Similarly, segmenting an interval of time leads to biases in duration judgments. To explore the involvement of temporal mechanisms in distance processing, we conducted a series of studies investigating aspects of traversed distance perception - a skill that typically involves integrating input from both proprioceptive and temporal duration information. In Exp. 1 we first explored the segmentation effect in time perception alone. It was found that if there were more intervening auditory events (identifying odd/even digits) during a temporal duration, subjects'(Ss') estimates of duration were longer. In Exp. 2, Ss traversed a distance and were then required to walk again to, both reproduce the extent of the learned distance and reproduce the duration of travel. Again intervening auditory events served as a means of segmenting the distance/duration. In Exp. 3, Ss traversed two distances and were required to make discrimination judgments related to either, the distance extent or the duration of travel. Different levels of segmentation were achieved by requiring Ss to pause briefly for a predetermined time period during one of the walked distances. For both Exp. 2 and Exp. 3, similar effects of segmentation were observed for distance reproduction and for duration reproduction, suggesting a possible shared mechanism