FUNCTIONAL LATERALIZATION FOR AUDITORY TEMPORAL PROCESSING IN MALE AND FEMALE RATS

In 3 studies adult male rats showed significantly better discriminatio n of tone sequences with the right ear than with the left ear. This re sult parallels similar findings of left-hemisphere specialization for auditory temporal processing in humans and nonhuman primates. Furtherm ore, because clinical evidence supports a link between specialization of the left hemisphere for auditory temporal processing and for speech processing, these results may reflect evolutionary precursors to left -hemisphere language specialization. Because male rats showed a strong er ear advantage than female rats, the findings may relate to evidence of a stronger right ear advantage in men than in women. Finally, resu lts suggest that neonatal handling enhances lateralization for auditor y temporal processing in both sexes. Combined results implicate neuroe ndocrine mechanisms as important factors in the development of lateral ization for auditory temporal processing.