Semantic transparency modulates the semantic perception of morphemes: Evidence from RSA of BOLD signals

There is no converging evidence on how a word's semantic transparency affects morphemes' potential semantic activation. The inconsistent results may be due to the limitation of traditional univariate analyses, in which the semantic transparency was treated as discrete categories. In the current study, Chinese two-character words were used as stimuli and functional magnetic resonance imaging (fMRI) techniques were combined with a priming paradigm. Unlike most previous studies, the multivariate representation similarity analysis (RSA) was used to treat semantic transparency as a continuous variable. The RSA results showed that widespread regions in the frontal-parietal-temporal network represent the semantic perception of characters in all words and transparent words, but no brain areas were identified in opaque words. Unlike RSA results, univariate analyses showed no significant difference between the opaque and transparent words. These results suggest that RSA is more suitable to examine the neural mechanism related to continuous variables such as semantic transparency.