Neural activation patterns, produced while listening to and reading words and non-words, were evaluated by functional MRI in 48 school children, mean age 8 years, in a study at Yale School of Medicine, New Haven, CT. Comparison of subsets of early, on-time and late talkers, matched for age, gender and performance IQ, showed that activation in bilateral thalamus and putamen, and left insula and superior temporal gyrus (circuits underlying speech and language) during these tasks was significantly lower in late talkers. Age of language acquisition has effects on reading and language behavior, and on corresponding cortical and subcortical neural circuitry. Late talkers were at risk for reading problems. The findings demonstrate the importance of early language development on formation of critical neural circuits and the need for prompt identification of language delays. [1]
COMMENT. This study underscores previous findings of the effect of age of talking on the development of language and literacy. Talking is strongly related to neural activation patterns, particularly in subcortical regions, putamen and thalamus, regions implicated in the Galaburda studies of dyslexia.