Sex‐related differences in hemispheric lateralization: A function of physical maturation

Abstract

The patterns of perceptual asymmetry on three dichotic listening tasks were evaluated to assess the hypothesis that late‐maturing individuals have more clearly lateralized cerebral functions. A total of 64 right‐handed prepubescent (n = 32) and postpubescent (n = 32) males and females, classified by physical exams as early or later maturers, were given dichotic listening tasks of consonant‐vowel syllables (CVs), simple square‐wave tones (STs), and complex square‐wave tones (CTs). Partial support was obtained for the maturation hypothesis, but in unexpected directions. There were no significant differences between early and late maturers in the magnitude of the dichotic right‐ear advantage (REA) for CVs, in either the prepubescent or postpubescent group. Only the postpubescent group obtained a significant REA, regardless of sex or maturation rate. In contrast, maturation rate was related to dichotic ST and CT tone performance. Late maturers demonstrated a stronger left‐ear advantage (LEA) in the prepubescent group, and early maturers demonstrated a stronger LEA in the postpubescent group, regardless of sex. These results suggest that maturation rate may contribute independently to left‐hemisphere and right‐hemisphere lateralization.