CEREBRAL ASYMMETRY AND COGNITIVE-DEVELOPMENT IN CHILDREN - A MAGNETIC-RESONANCE-IMAGING STUDY

Phonemic awareness, the ability to abstract and manipulate auditory sy mbols, is a distinguishing human characteristic. Neurobiological speci alizations in the left hemisphere and cultural exposure to language in teract to shape development of this ability. Modern imaging techniques now permit investigation of the interaction of these forces. In this initial doss-sectional study, we found evidence for a shift from neuro biological to cultural regulation. In young children, aged 5 to 9, ana tomical asymmetry of the auditory association cortex predicted phonemi c awareness. In older children, the relationship disappeared, as all c hildren became skilled readers. The findings suggest that children wit h differ ent patterns of cognitive strengths and weaknesses may have d ifferent spatiotemporal patterns of cortical development.