A cardinal feature of schizophrenia is the poor comprehension, or misinterpretation, of the emotional meaning of social interactions and events, which can sometimes take the form of a persecutory delusion. It has been shown that the comprehension of the emotional meaning of the social world involves a midline paralimbic cortical network. However, the function of this network during emotional appraisals in patients with schizophrenia is not well understood. In this study, hemodynamic responses were measured in 14 patients with schizophrenia and 18 healthy subjects during the evaluation of descriptions of social situations with negative, positive, and neutral affective valence. The healthy and schizophrenia groups displayed opposite patterns of responses to emotional and neutral social situations within the medial prefrontal and posterior cingulate cortices—healthy participants showed greater activity to the emotional compared to the neutral situations, while patients exhibited greater responses to the neutral compared to the emotional situations. Moreover, the magnitude of the response within bilateral cingulate gyri to the neutral social stimuli predicted delusion severity in the patients with schizophrenia. These findings suggest that impaired functioning of cortical midline structures in schizophrenia may underlie faulty interpretations of social events, contributing to delusion formation.

Recent event-related potential studies report a P600 effect to incongruous verbs preceded by semantically associated inanimate noun-phrase (NP) arguments, e.g., "eat" in "At breakfast the eggs would eat...". This P600 effect may reflect the processing cost incurred when semantic-thematic relationships between critical verbs and their preceding NP argument(s) bias towards different interpretations to those dictated by their sentences’ syntactic structures. We have termed such violations of alternative thematic roles, ’thematic role violations.’ Semantic-thematic relationships are influenced both by semantic associations and by more basic semantic features, such as a noun’s animacy. This study determined whether a P600 effect can be evoked by verbs whose thematic structures are violated by their preceding inanimate NP arguments, even in the absence of close semantic-associative relationships with these arguments or their preceding contexts. ERPs were measured to verbs under four conditions: (1) non-violated ("At breakfast the boys would eat..."); (2) preceded by introductory clauses and animate NPs that violated their pragmatic expectations but not their thematic structures ("At breakfast the boys would plant..."); (3) preceded by semantically related contexts but inanimate NPs that violated their thematic structures ("At breakfast the eggs would eat..."); (4) preceded by semantically unrelated contexts and inanimate NPs that also violated their thematic structures ("At breakfast the eggs would plant..."). Pragmatically non-thematic role violated verbs preceded by unrelated contexts and animate NPs evoked robust N400 effects and small P600 effects. Thematically violated verbs preceded by inanimate argument NPs evoked robust P600 effects but no N400 effects, regardless of whether these inanimate arguments or their preceding contexts were semantically related or unrelated to these verbs. These findings suggest that semantic-thematic relations, related to animacy constraints on verbs’ arguments, are computed online and can immediately impact verb processing within active, English sentences.