Participation of the left posterior inferior temporal cortex in writing and mental recall of kanji orthography - A functional MRI study

To examine the neuropsychological mechanisms involved in writing kanji (mor phograms), we used functional MRI (fMRI) in 10 normal volunteers, all right -handed, native Japanese speakers. The experimental paradigms consisted of kana-to-kanji transcription, mental recall of kanji orthography and oral re ading and semantic judgement of kana words. The first two tasks require man ual and mental transcription of visually presented kana words into kanji, r espectively, whereas the last two tasks involve language processing of the same set of stimulus words without recall of kanji. The transcription and m ental recall tasks yielded lateralized activation of the left posterior inf erior temporal cortex (PITC). By contrast, neither oral reading nor semanti c judgement produced similar activation of the area. These results, in good accordance with lesion data, provide converging evidence that the left PIT C plays an important role in writing kanji through retrieval of their visua l graphic images, and suggest language-specific cerebral organization of wr iting. The set of fMRI experiments also provides new neuroimaging data on t he cortical localization of basic language functions in people using a non- alphabetical language.