Learning Letters in Adulthood: Direct Visualization of Cortical Plasticity for Forming a New Link between Orthography and Phonology.

HFSP Grant Awardee Kuniyoshi L. Sakai and colleagues

It is not known which brain regions in adults show plasticity for learning letters. In the April 22 issue of Neuron, HFSP Young Investigator Kuniyoshi L. Sakai and colleagues reported that the left inferior temporal and parietal regions (red regions in an MRI map) are critical in learning to associate letters with speech sounds, whereas the bilateral superior temporal regions (blue regions) are recruited for already acquired orthography. The letters shown under the left and right brains are kana and Hangul letters used in the study, respectively. Each of the other letters represents a vowel (/a/, /i/, /o/; except Hebrew) used currently in the world. This fMRI study establishes that the human adult brain is still adaptable to new associations between orthographic and phonological stimuli, and that this type of learning is achieved in only two days by the rapid plasticity of a functional system critically involving the left inferior temporal and parietal regions.

Reference:
"Learning Letters in Adulthood: Direct Visualization of Cortical Plasticity for Forming a New Link between Orthography and Phonology." Hashimoto, R. and Sakai, K. L. Neuron, 42, 311-322 (2004).