Although prediction plays an important role in language comprehension, its precise neural basis remains unclear. This fMRI study investigated whether and how semantic-category-specific and common cerebral areas are recruited in predictive semantic processing during sentence comprehension. We manipulated the semantic constraint of sentence contexts, upon which a tool-related, a building-related, or no specific category of noun is highly predictable. This noun-predictability effect was measured not only over the target nouns but also over their preceding transitive verbs. Both before and after the appearance of target nouns, left anterior supramarginal gyrus was specifically activated for tool-related nouns and left parahippocampal place area was activated specifically for building-related nouns. The semantic-category common areas included a subset of left inferior frontal gyrus during the anticipation of incoming target nouns (activity enhancement for high predictability) and included a wide spread of areas (bilateral inferior frontal gyrus, left superior/middle temporal gyrus, left medial pFC, and left TPJ) during the integration of actually perceived nouns (activity reduction for high predictability). These results indicated that the human brain recruits fine divisions of cortical areas to distinguish different semantic categories of predicted words, and anticipatory semantic processing relies, at least partially, on top–down prediction conducted in higher-level cortical areas.

In an event-related potential experiment with Chinese discourses as material, we investigated how and when accentuation influences spoken discourse comprehension in relation to the different information states of the critical words. These words could either provide new or old information. It was shown that variation of accentuation influenced the amplitude of the N400, with a larger amplitude for accented than for deaccented words. In addition, there was an interaction between accentuation and information state. The N400 amplitude difference between accented and deaccented new information was smaller than that between accented and deaccented old information. The results demonstrate that, during spoken discourse comprehension, listeners rapidly extract the semantic consequences of accentuation in relation to the previous discourse context. Moreover, our results show that the N400 amplitude can be larger for correct (new, accented words) than incorrect (new, deaccented words) information. This, we argue, proves that the N400 does not react to semantic anomaly per se, but rather to semantic integration load, which is higher for new information.