Length distortion of temporally extended visual displays: Similarity to haptic spatial perception

Abstract

Three experiments were designed to investigate length distortion-the tendency to inflate estimates of the inferred distance between two points, as the length of a circuitous pathway between them increases. This phenomenon, previously demonstrated with haptic and locomotor exploration (Lederman, Klatzky, Collins, & Wardell, 1987), was extended to vision through the presentation of pathways as a temporal sequence of illuminated points. The magnitude of the visual effect was less than that previously found in haptics, and conditions promoting the effect included a relatively slow presentation rate and moderately complex pathways. Commonalities in the pattern, if not the magnitude, of length distortion in vision and haptics suggest that similar processes of spatial encoding may underlie the phenomenon in both domains.A pattern of systematic error, called length distortion, has been documented in haptic spatial perception (Lederman, Klatzky, & Barber, 1985; Lederman, Klatzky, Collins, & Wardell, 1987). It is a tendency to overestimate the inferred distance between two points, when a circuitous pathway is followed between them. The phenomenon has been found for bothsmall-scale displays explored with the fingertip and large-scale displays explored through locomotion. In the present paper, we investigate whether a similar phenomenon occurs under certain conditions of visual exposure to a pathway.The critical conditions are suggested by obvious differences between the circumstances under which spatial information is obtained in "movement space" (Lederman et al., 1987), as compared with visual perception. Specifically, haptic encoding is usually temporally extended; only a small, local sample of a spatial domain can be obtained at anyone time.Extending patterns over time imposes two kinds of demands: memory and integration. To consider the first of these, the loss of spatial information over time should profoundly impair the ability to construct a representation from a sequence of samples, in both haptics and vision. Short-term forgetting of movement and position infonnation has been documented (as reviewed in Stelmach, 1982), as has the forgetting of the position of a dot in a visual display (Nelson & Chaiklin, 1980;Taylor, 1961) We acknowledge the support of the Office of Naval Research (contract to Roberta L. Klatzky and Susan I. Lederman). We also thankthe UCSB Center for Spatial Cognition andPerformance for access to multiuserequipment. Correspondence may be addressed tol. D. Balakrishnan, Department of Psychology, University of California, Santa Barbara, CA 93106. 387and in a haptic one (Lederman & Taylor, 1969). The second (and related) demand imposed by temporally extended patterns is the need to integrate information, in order to obtain a global, survey type of spatial representation. Visual integration has been studied in experiments that involve an aperture-or slit-viewing procedure (Anstis & Atkinson, 1967;Hochberg, 1968;Rock, 1981) or thepresentation of spatially separated elements of a single form (Klatzky ...

The tactual horizontal-vertical illusion depends on radial motion of the entire arm

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Similarity of Tactual and Visual Picture Recognition with Limited Field of View

“…If there is more uncertainty or distortion associated with the kinesthetic monitoring of hands and fingers than with that of the eyes (relative to the size of the patterns being scanned), as appears plausible (Klatzky and Lederman 1987;Balakrishnan et al 1989), then one would expect touch to be at some disadvantage relative to vision in the integration of successive patterns of receptor activation.…”

Tactile search for change has less memory than visual search for change

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