Detecting syntactic and semantic anomalies in schizophrenia

One of the major challenges in the study of language inschizophrenia is to identify specific levels of the linguistic structurethat might be selectively impaired. While historically a main semanticdeficit has been widely claimed, results are mixed, and there is evidenceof syntactic impairment as well. This might be due to heterogeneity inmaterials and paradigms across studies, which often do not allow to tapinto single linguistic components. Moreover, the interaction betweenlinguistic and neurocognitive deficits is still unclear. In this study,we concentrated on syntactic and semantic knowledge. We employed ananomaly detection task including short and long sentences with eithersyntactic errors violating the principles of Universal Grammar, or anovel form of semantic errors, resulting from a contradiction in thecomputation of the whole sentence meaning. Fifth-eight patients withdiagnosis of schizophrenia were compared to 30 healthy subjects. Resultsshowed that, in patients, only the ability to identify syntactic anomaly,both in short and long sentences, was impaired. This result cannot beexplained by working memory abilities or psychopathological features.These findings suggest the presence of an impairment of syntacticknowledge in schizophrenia, at least partially independent of thecognitive and psychopathological profile. On the contrary, we cannotconclude that there is a semantic impairment, at least in terms ofcompositional semantics abilities.