Perceptual dimensions of infants' cry signals : a dissertation present in partial fulfilment of the requirements for the degree of Master of Philosophy in Education at Massey University

Abstract

Two experiments were performed to uncover perceptual dimensions of 24 infant cry signals. In Experiment 1, the 24 cries were rated by listeners on 50 semantic differential scales. A factor analysis of the ratings uncovered three meaningful factors (Effect, Potency & Value) which emphasise emotional aspects of the cries, and support a suggestion that different cry-types essentially differ along a continuum of intensity/aversiveness. In Experiment 2, the method of pair-comparisons was used to obtain cry similarity ratings which were submitted to INDSCAL (a multidimensional scaling program). Three dimension were uncovered which emphasise physical aspects of the cries. These dimensions (Potency, Form and Clarity) were labelled in terms of the 50 semantic differential scales using standard linear multiple regression. For both experiments, accurate predictions of cry recognition results were made from the cry similarity data, suggesting that the listeners attended to the same cry features in each task. A canonical analysis of the semantic differential factor scores and the INDSCAL dimension weights revealed two significant canonical correlations, which suggests that the two techniques are essentially describing the same perceptual space. The relative advantages of the semantic differential and the method of pair-comparisons (coupled to INDSCAL) are discussed, and also the possibility of applying the semantic differential to study different cry-types, clinically abnormal cries, and the effects of crying on the caregiver