Independence and separability in the perception of complex nonspeech sounds

Abstract

All sounds are multidimensional, yet the relationships among auditory dimensions have been studied only infrequently. General recognition theory (GRT; Ashby & Townsend, 1986) is a multidimensional generalization of signal detection theory and, as such, provides powerful tools well suited to the study of the relationships among perceptual dimensions. However, previous uses of GRT have been limited in serious ways. We present methods designed to overcome these limitations, and we use these methods to apply GRT to investigations of the relationships among auditory perceptual dimensions that previous work suggests are independent (frequency, duration) or not (fundamental frequency [ f 0], spectral shape). Results from Experiment 1 confirm that frequency and duration do not interact decisionally, and they extend this finding with evidence of perceptual independence. Results from Experiment 2 show that f 0 and spectral shape tend to interact perceptually, decisionally, or both, and that perceptual interactions occur within, but not between, stimuli (i.e., the interactions suggest correlated noise across processing channels corresponding to perceptually separable dimensions). The results are discussed in relation to lower level sensory modeling and higher level cognitive and linguistic issues.

Decisional separability, model identification, and statistical inference in the general recognition theory framework

“…Given that failure of decisional separability is not identifiable in the factorial identification paradigm and associated GRT model, and given that the presence of perceptual separability and independence cannot, in general, be guaranteed a priori, there is pragmatic value in simply assuming that decisional separability holds (as in Wickens, 1992). First and foremost, this assumption enables rigorous tests of perceptual separability and independence, through tests of marginal response invariance (Ashby & Townsend, 1986;Silbert, 2010;Thomas, 2001b;Wenger & Ingvalson, 2003), through comparison of marginal signal detection parameters (Kadlec & Townsend, 1992a;Thomas, 2001b;Wenger & Ingvalson, 2003), or through model fitting and comparison (Olzak & Wickens, 1997;Silbert et al, 2009;Thomas, 2001b;Wickens, 1992).…”

“…The four response regions are given generic labels, indicating combinations of low (L) and high (H) levels on each dimension. These could correspond, for example, to the narrow/wide eye width and short/long nose length of the face stimuli used by Thomas (2001b) or the short-/long-duration and low-/high-frequency ranges of the broadband noise stimuli used by Silbert et al (2009).…”

“…The structure of general recognition theory General recognition theory, or GRT, is a multidimensional model of perception and response selection (Ashby & Townsend, 1986;Kadlec & Townsend, 1992a, 1992bSilbert, Townsend, & Lentz, 2009;Thomas, 2001b;Wenger & Ingvalson, 2003). It was originally developed to unify a disparate set of concepts in the psychological literature and provide a rigorous mathematical foundation for the analysis of interactions between psychological dimensions in perception and response selection.…”

The Integration of Stimulus Dimensions in the Perception of Music

“…By using a task that required explicit classificationsdichotomous judgments of conformity -of pitch or temporal structure in a melody, the stimulus manipulations should, theoretically, make a dimension truly irrelevant, rather than requiring active cognitive effort to suppress its contribution to the participant's response. Classification paradigms have a long history in research on dimensional integration (Garner, 1974;Pomerantz, 1983) and are still relevant today (for recent in audition see Dyson & Quinlan, 2010;Silbert, Townsend, & Lentz, 2009). Therefore Experiment 3 had the same melodies and same instructions, but changed the task.…”

Perception of voicing and place of articulation in labial and alveolar English stop consonants

“…It will be assumed that the perceptual distributions are bivariate Gaussian, an assumption that is common in applications of GRT (Olzak and Wickens 1997;Kadlec and Hicks 1998;Thomas 2001;Silbert et al 2009;Silbert 2012). In addition to being a common assumption in applications of GRT, Gaussian perceptual dis tributions have at least two useful properties.…”