Configural effects in perceived pointing of ambiguous triangles.

Abstract

Five experiments examined the influence of configural variables on perceived pointing of ambiguous (equilateral) triangles. The amount of time required to see the triangles point in specified directions was measured for single triangles and linear configurations of multiple triangles. The results show that perceived pointing is biased toward directions that are coincident with or perpendicular to the configural line. Perceptual interference occurs when the configural line biases pointing away from the correct direction, and facilitation sometimes occurs when it biases pointing toward the correct direction. The magnitude of interference increases (a) when the required direction is perceptually less salient, (b) when the configural line contains more triangles, and (c) when the triangles are closer together. Further results suggest that the spacing effect depends on relative rather than absolute distance and that the number and spacing effects are additive. In addition, substantial differences were found among individuals in terms of their susceptibility to configural interference. These results are discussed in terms of a sequential sampling model of perceived pointing. The samples result from spontaneous alternations in a multistable system of three mutually inhibitory directional subsystems. It is proposed that configural effects arise from low resolution pattern information that influences the behavior of the multistable system. Possible mechanisms are suggested through which directional, attentional, and individual differences might also arise.

Effects of motion on perceived pointing of ambiguous triangles

“…Resultsfrom both tasks showed systematic biases due to the relation between the direction of motion and the structure ofthe triangle: Motion along an axis ofsymmetry (parallel to a possible direction of pointing) facilitated perceived pointing along that axis. However, motion along a side of the triangle (perpendicular to a possible direction of pointing) produced no such facilitative effect, in contrast to analogous perpendicular effects in previous studies using static patterns (Palmer, 1980;Palmer & Bucher, 1981, 1982. These results are interpreted as evidence that event symmetry is an important stimulus characteristic underlying directional biases due to motion.…”

“…We hoped to find out which ones, if any, induced systematic biases in perceived pointing. The second experiment employed a more rigorous, performance-oriented "interference" paradigm (Palmer & Bucher, 1981, 1982 to provide converging evidence about the same issues.…”

“…One hypothesis is that the critical feature is the elongation of linear configurations and textural stripes (Palmer, 1980;Palmer & Bucher, 1981, 1982see, also, Humphreys, 1983, andWiser, 1981). This "elongation hypothesis" accounts quite nicely for the axis-aligned effects.…”

“…The Equilateral triangles are perceptually ambiguous figures in that they can be seen to point in anyone of three directions (see Figure lA), but in only one of them at any given moment (Attneave, 1968). The direction in which such triangles are perceived to point can be systematically biased by contexts such as linear configurations composed of several equilateral triangles (Attneave, 1968;Palmer, 1980;Palmer & Bucher, 1981) and textural stripes inside a single triangle (Palmer & Bucher, 1982). When the orientation of the configuralline or texture is aligned with one of the triangle's three axes of symmetry, observers tend to see the triangle point in a direction that coincides with that axis (see the "axis-alignment" conditions shown in Figures IB and ID).…”

Perceptual Switching, Eye Movements, and the Bus Paradox

“…Attneave observed that these triangles are perceived alternatively to point in any of these three directions with approximately equal preference. The preferences for these directions have been investigated in relation to motion (Bucher and Palmer 1985), texture (Palmer and Bucher 1982), and configuration (Palmer and Bucher 1981). Spontaneous switching between these directions has been reported for prolonged viewing conditions (Attneave 1968(Attneave , 1971).…”