Factor analysis of lateralized auditory perceptual resources

Abstract

The primary goal of this study was to identify independent, hemispherically lateralized auditory perceptual resources so that they could be used to expand the Multiple Resources Questionnaire (MRQ), an existing measure that assesses the demands that a task places upon multiple resources (Boles & Adair, 2001a). Researchers have demonstrated that the MRQ's subjective ratings of resource demand can be used to predict multi-task interference, and the measure has demonstrated advantages over other subjective measures of task demand (for review Boles & Dillard, in press). Yet, of the 13 perceptual resources represented by the MRQ, only two are auditory. This shortage of auditory resources in the MRQ prevents the accurate measurement of tasks presented within the auditory modality, and the diagnosticity of the MRQ would likely benefit from the addition of items representing auditory resources (Finomore et al., 2008). The methods used to identify auditory resources in the present study were the same as those used to identify the bulk of the resources that are currently represented within the MRQ. A comprehensive survey of auditory perceptual research was conducted to identify the types of processing and tasks that appear to demand hemispherically lateralized perceptual resources. Based on this literature review, 13 tasks were selected for use in the current study. These tasks were administered as a test battery to 124 right-handed, nonmusicians. All significant, reliable performance asymmetries produced by these tasks were factor analyzed in order to identify underlying perceptual resources. Exploratory factor analysis revealed evidence for a novel right-lateralized Auditory Spectral Pitch resource which is specialized for processing and perceiving pitch based on the harmonic content in complex sounds. Results also indicated the possible existence of a right-lateralized Auditory Intensity resource, which is specialized for the processing of perceived intensity (i.e. loudness). However, the existence and independence of this Auditory Resource is suggested cautiously, since the data used to infer the resource was relatively unreliable. Additionally, two previously identified resources were evident in the current results: the Auditory Linguistic and Visual Temporal resources. The theoretical implications and human factors applications of these findings are discussed.