ABSTRACT
This chapter explores the relationship between the perceptual representation of complex stimuli and decision processes. It presents a view of similarity-judgment and identification processes that assumes: that complex visual or auditory stimuli are represented perceptually as points in a multidimensional, geometric space; and that similarity judgments are (inversely) related to interstimulus distance in the perceptual space. The similarity-judgment and identification processes also assumes that identification judgments are described by a probabilistic decision rule based on the pattern of interpoint distances in the perceptual space. A set of complex auditory or visual stimuli may be physically represented in a multidimensional space consisting of some number, perhaps very large, of orthogonal physical dimensions. Interdimensional additivity specifies that interstimulus distance is a function of the sum of the dimension-wise contributions. The multidimensional scaling analysis of similarity judgments identified a space of some dimensions that accounted for most of the observed variability.
