Hemispheric Specialization for listening to speech in neonate’s brain: Right for Melodies and Left for Vowels?
Yasuyo Minagawa-Kawai, Project Associate Professor, Shigeru Watanabe, Professor (Global COE-CARLS, Graduate School of Human Relations, Keio University), Takeshi Arimitsu, Instructor, Kazushige Ikeda, Assistant Professor, and Takao Takahashi, Professor, (Department of Pediatrics, School of Medicine, Keio University), have published the following results on the brain
functions related to language in newborn infants.
The study team measured the brain activation in newborn infants on listening to changes in the intonation of words and in the vowels of words to examine the functional difference of the two hemispheres at this age. The results indicated that neonates showed brain response to the intonation chiefly in the right auditory area. Although there is no asymmetrical response in the auditory area to the vowel contrast, strong response was observed in the left supramarginal gyrus, which is a part of the language area.
In adults, it is known that the right hemisphere is preferentially involved in processing melodies such as musical tunes or intonation, whereas the left hemisphere is more engaged in processing of vowel and consonant sound changes.
The results of this study show that the processing of intonation in neonates is already lateralized to the right hemisphere as it is in adults.
This study is the first to show the specialization of cerebral functions in the processing of intonation and phonemic events, and their lateralization, in newborns.
The research results were published in the electronic version of Frontiers in Psychology,September 15.
