Showing papers by "Barbara Tversky published in 1991"

Spatial mental models

Abstract: Publisher Summary This chapter reviews that spatial descriptions spontaneously construct spatial mental models of the described scenes as a natural consequence of reading for comprehension and memory, with no special training, instructions, or prior visual displays. The spatial mental models constructed reveal people's conceptions of space, which, though built on their perceptions of space, are more abstract and general. In the first set of experiments, subjects read route or survey descriptions of four environments, and verified verbatim and inference statements about those environments from both the same and the other perspective. Subjects were equally fast and accurate in verifying inference statements from the read perspective and the other perspective. This led to the conclusion that subject's mental models capture the categorical spatial relations described in the text, but not from any particular perspective. Like structural descriptions, spatial mental models contain information about the parts of a scene and the relations between the parts. Unlike images, which have been likened to internalized perceptions, spatial mental models are perspective-free and allow the taking of many perspectives, required in order to verify the test statements. The second set of studies examined perspective taking and information retrieval in a particular, one that is simple and common, that of an observer surrounded by objects. The chapter reviews that the experiments reported have added to that body of research, uncovering many features of spatial mental models in the process.

Distortions in memory for visual displays

Abstract: Systematic errors in perception and memory present a challenge to theories of perception and memory and to applied psychologists interested in overcoming them as well. A number of systematic errors in memory for maps and graphs are reviewed, and they are accounted for by an analysis of the perceptual processing presumed to occur in comprehension of maps and graphs. Visual stimuli, like verbal stimuli, are organized in comprehension and memory. For visual stimuli, the organization is a consequence of perceptual processing, which is bottom-up or data-driven in its earlier stages, but top-down and affected by conceptual knowledge later on. Segregation of figure from ground is an early process, and figure recognition later; for both, symmetry is a rapidly detected and ecologically valid cue. Once isolated, figures are organized relative to one another and relative to a frame of reference. Both perceptual (e.g., salience) and conceptual factors (e.g., significance) seem likely to affect selection of a reference frame. Consistent with the analysis, subjects perceived and remembered curves in graphs and rivers in maps as more symmetric than they actually were. Symmetry, useful for detecting and recognizing figures, distorts map and graph figures alike. Top-down processes also seem to operate in that calling attention to the symmetry vs. asymmetry of a slightly asymmetric curve yielded memory errors in the direction of the description. Conceptual frame of reference effects were demonstrated in memory for lines embedded in graphs. In earlier work, the orientation of map figures was distorted in memory toward horizontal or vertical. In recent work, graph lines, but not map lines, were remembered as closer to an imaginary 45 deg line than they had been. Reference frames are determined by both perceptual and conceptual factors, leading to selection of the canonical axes as a reference frame in maps, but selection of the imaginary 45 deg as a reference frame in graphs.

Parts and the basic level in natural categories and artificial stimuli: Comments on Murphy (1991)

Abstract: Natural taxonomies consist of categories that vary in level of abstraction. Categories at the basic level, such as chair and apple, arepreferred in a broad range of situations (Rosch, Mervis, Gray, Johnson, & Boyes-Braem, 1976). Several studies have revealed qualitative differences between the basic level and other levels. For example, Tversky and Hemenway (1984) presented evidence that parts proliferate at the basic level, they proposed that parts link the appearance of category members with their functions. Although not taking issue with these findings, Murphy (1991) investigated whetherparts are necessary or sufficient for a basic level In an attempt to demonstrate that parts are not necessary, Murphy used artificial stimuli that did not capture the essential features of natural taxonomiea These discrepancies preclude any conclusions based on his studies. Murphy’s data also do not support his claim that parts are not sufficient for a basic level Finally, ii is unlikely that pur8uing questions of necessity or sufficiency will produce insights into human categorization.