Does Binocular Disparity or Familiar Size Information Override Effects of Relative Size on Judgements of Time to Contact?

Abstract

Previous studies indicate that non-tau sources of depth information, such as pictorial depth cues, can influence judgements of time to contact (TTC). The effect of relative size on such judgements, the size-arrival effect, is particularly robust. However, earlier studies of the size-arrival effect did not include binocular disparity or familiar size information. The effects of these cues on relative TTC judgements were measured. Results suggested that disparity can eliminate the size-arrival effect but that the amount of disparity needed to do so is greater than typical stereoacuity thresholds. In contrast, familiar size eliminated the size-arrival effect even when disparity information was not available. Furthermore, disparity contributed more to performance when familiar size was present than when it was absent. Consistent with previous studies, TTC judgements were influenced by multiple sources of information. The present results suggested further that familiar size is one such source of information and that familiar size moderates the influence of binocular disparity information.

Effects of a moving distractor object on time-to-contact judgments.

“…This result is compatible with previous reports that observers use simple pictorial cues, such as retinal size, in TTC estimation (DeLucia, 1991(DeLucia, , 2005. As there was no interaction between presentation duration and distractor condition, however, the effects of the distractor objects cannot be attributed to the use of size information.…”

Effects of texture and shape on perceived time to passage: Knowing “what” influences judging “when”

“…Thus, the deformation is not ignored. This new factor adds to previous ones that have been found to affect TTP judgments: familiar size (DeLucia, 2005) and image velocity (Kerzel, Hecht, & Kim, 1999).…”

Interceptive timing: Prior knowledge matters

“…This could be due to additional size information arising from disparity or the ratio _ E (Regan & Beverly, 1979), resolving ambiguities in size categorization. DeLucia (2005) presented observers with two objects that approached at the same velocity and had the same TTC but asked participants to make a judgment as to which would arrive first. Observers erred toward the object that was larger, but providing information about size differences eliminated this size-arrival effect.…”