Functional Segregation of Semantic Memory and Processing in Ventral Inferior Frontal Gyrus

摘要

Although many studies in neuroimaging showed that semantic tasks activated the left ventral inferior frontal gyrus (LvIFG), whether there is the functional segregation of LvIFG in the semantic memory and semantic processing remains unclear. In order to determine neural differences of semantic memory and processing in LvIFG with functional MRI, thirty-six subjects performed reading tasks on triplets of either text or figure or text-figure. The text/figure/figure+text tasks activated two common areas located in an anterior portion of LvIFG and a posterior portion of LvIFG. The BOLD signal change of the posterior portion of LvIFG has semantic working memory characteristics because semantic repetition priming and the BOLD signal change of anterior portion of LvIFG has information processing characteristics. The results suggest that the posterior portion of LvIFG unrelated to information forms is for semantic memory, whereas the anterior portion of LvIFG related to information forms is for semantic processing.