The Relationship between Hemispheric Laterality and Perception of Musical and Verbal Stimuli in Normal and Learning Disabled Subjects

Abstract

The purpose of this study was to examine hemispheric laterality in relation to the perception of musical and verbal stimuli in normal and learning disabled (LD) subjects. Dichotic listening tests included a Verbal Test, utilising con- sonant-vowel syllables, a Tonal Test, and a Rhythm Test. Each musical test was divided into three subtests, with tonal and rhythm patterns categorised according to difficulty level. The tests were administered to 38 normal and 38 LD subjects, between grades one and four. Data were analysed by means of multivariate analysis of variance (MANOVA) procedures. Major findings included: (1) significant differences among subject groups in the magnitude but not the direction of laterality; (2) significantly greater absolute cal- advantage (AEA) values for the LD subjects than for the normal subjects on the Verbal Test, composite Tonal Test, and Difficult Rhythm subtest; and (3) significantly greater AEA values for younger than for older subjects on the easy and moderately difficult Tonal subtests.