Abstract
To clarify whether Broca's subregions comprising the parts opercularis(Op) and the parts triangularis(Tr) display different roles in syntactic processing, we investigated Japanese infarct patients with selective damage in each subregion. Using the Object Manipulation Task (with subjects required to manipulate a toy animal after listening to a reversible sentence, e.g. "A squirrel gave an elephant to a tiger"), accuracy and error types were compared between patient groups. The Op group displayed difficulty with relative sentences, whereas the Tr group showed more difficulty with dative sentences than with relative sentences. the Tr group tended to posit items in canonical order, while the Op group posited items in random order. Scrambled active sentences were difficult for both groups. Considering the Japanese sentence structure, the results indicate that Op is involved in serial-order aspects in syntactic processing, while Tr is involved in semantic aspects.
