The role of inferior frontal gyrus in processing Chinese classifiers

The Chinese classifier system classifies nouns and builds a relation between classifiers and their corresponding nouns. This functional magnetic resonance imaging (fMRI) study examined brain activation of Chinese classifiers during reading comprehension. Thirty-four participants read and performed semantic congruency judgments on congruent, inside-classifier (IC) violated, and outside-classifier (OC) violated sentences. The IC and OC violations were created by changing the correct classifier to an inappropriate classifier and a non-classifier, respectively. The comparison of the IC violation vs. the congruent condition produced greater activation in the mid-ventral region (BA 45) of the left inferior frontal gyrus (IFG), suggesting an increased demand on semantic processing. Contrasting different subtypes of IC violation produced greater activation in the right IFG (BAs 45 and 47), indicating that processing mass/count classifiers involves distinct brain activations. The OC violation produced greater activation in the left IFG (BAs 45 and 44), suggesting both semantic and syntactic processing. These results indicate that different parts of the IFG contribute to syntactic and semantic processing of classifier phrases in reading Chinese for comprehension.