Language-related brain regions during “shiritori” task (Japanese capping verses): a spatial filtered MEG analysis

Abstract There is a Japanese traditional word game, “shiritori” (capping verses), analogous to English word generation. “Shiritori” task is characterized by demanding a subject to detect the phonetic factor of words as well as to generate words, and is expected to activate brain regions related to phonological processing, such as Wernicke's area. The aim of this study is to visualize neural activated brain regions during performance of a “shiritori” task using a MEG neuroimaging technique, Synthetic Aperture Magnetometry (SAM). Eight healthy right-handed, native Japanese speakers were studied. They gave their informed consents. Subjects were instructed to play “shiritori” by themselves silently during the “shiritori” task. In 8–25 Hz band, neural activated regions (corresponding to event-related desynchronization) were estimated in language-related brain regions with left-side dominancy: dorsolateral prefrontal cortex (DLPFC), post-inferior frontal gyrus (IFG), primary motor cortex, post-superior temporal gyrus (STG), visual cortex, inferior parietal lobule. The results suggest that the “shiritori” task requires neural activations in Wernicke's area more strongly when compared with verbal fluency paradigm and that this task can be used for assessing pathophysiology of diseases with dysfunction of Wernicke's area such as schizophrenia.