On the relation between decision rules and perceptual representation in multidimensional perceptual categorization

Abstract

This article examines the relation between changing categorization decision rules and the nature of the underlying perceptual representation. Observers completed a matching task that required them to adjust the length and orientation of a single line stimulus until they perceived it to "match" a second line stimulus (Alfonso-Reese, 1996. The same observers then completed four categorization tasks with the same stimuli. Data from the matching task were used to estimate a perceptual representation for each stimulus and observer. Three hypotheses regarding potential interactions between categorization decision rules and perceptual representation were examined. One assumed that there was no interaction between decision rules and perceptual representation. The second assumed that linear categorization rules affect the perceptual representation differently from nonlinear categorization rules. The third assumed that dimensional integration rules affected the perceptual representation differently from decision rules that require the observer to set a criterion along one stimulus dimension while ignoring the other; this is referred to as decisional selective attention. The results suggested that (l) the matching task perceptual representation provided a good account of the categorization data, (2) decisional selective attention affected the perceptual representation differently from decisional integration, and (3) decisional selective attention generally decreased the perceptual variability along the attended dimension.Categorization is a primary component of many behaviors ofall organisms (Alcock, 1989). In general, each category exemplar can be decomposed into a set of values along multiple basic stimulus dimensions, each of which is continuous rather than binary valued (e.g., Ashby, 1992a;. For example, category exemplars may vary along the dimensions of size, length, orientation, color, location, frequency, and amplitude. Because each dimension is processed differently by the perceptual system, it is important to understand the nature of the perceptual representation and how it affects categorization performance (Alfonso- Reese, 1997;Ashby & Lee, 1991;Nosofsky, 1986). Conversely, recent research suggests that the act of categorization might alter the structure of the perceptual representation (e.g., Ashby & Lee, 1991;Goldstone, 1994;Nosofsky, 1986). In particular, different categorization rules might alter the structure of the perceptual representation in different ways. This article addresses both of these issues within a single exThis research was supported in part by National Science Foundation Grant SBR-9796206 and NIH Grant ROI MH59196. We thank Helena Kadlec, Robin Thomas, and an anonymous reviewer for helpful comments on an earlier draft ofthis manuscript. We also thank Greg Ashby, Leslie Cohen, Randy Diehl, Bill Geisler, David Gilden, Art Markman, and Tom Thornton for discussions that influenced this work. Correspondence should be addressed to W. T. Maddox, Department of Psychology, Mezes Hall 330, Universit...

A strong test of the dual-mode hypothesis

“…The ability to perform these tests draws on more than 3 decades of theoretical and empirical advances (based on critical contributions from Schweickert, 1978Schweickert, , 1983Schweickert et al, 2000;Townsend, 1972Townsend, , 1974Townsend & Ashby, 1978;Townsend & Nozawa, 1995;and Townsend & Schweickert, 1989, among others). It is our hope that this study, like others demonstrating the application of experimental methodologies with strong links to formally specified theories of psychological information and processes (e.g., Ashby, Alfonso-Reese, Turken, & Waldron, 1999;Maddox & Bogdanov, 2000;Thomas, 1996;Townsend & Nozawa, 1995;Wenger & Ingvalson, 2002Wenger & Townsend, 2001), will lead to strong tests of a variety of hypotheses and, thus, enliven the ongoing empirical and theoretical discussions of facial cognition. S(t) ϭ 1 Ϫ F(t) and F(t) ϭ 1 Ϫ S(t).…”

Generalizing a neuropsychological model of visual categorization to auditory categorization of vowels

“…In particular, the effects of learning can be examined (Maddox, 2002). Finally, a more complete understandingof auditory stimulus processing can be obtained by modeling performance simultaneously across these two different, but related, tasks (Ashby & Lee, 1991;Maddox & Ashby, 1996; see also Maddox & Bogdanov, 2000).…”

The prioritization of perceptual processing in categorization

“…Two models that do this are decision bound theory (Ashby & Gott, 1988;Ashby & Maddox, 1994) and the extended generalized context model (EGCM; Lamberts, 1995Lamberts, , 1998Lamberts, , 2000. Maddox and colleagues have conducted a series of experiments using decision bound theory to examine the perceptual effects of attention in categorization (Maddox, 2001;Maddox & Bogdanov, 2000;Maddox & Dodd, 2003). These studies have shown that category structure-and hence, the type of decision required during categorizationappears to mediate any effects of attention on perception.…”