Semantic processing features and schizotypal traits: A test-retest study

Semantic processing abnormalities have been observed across the schizophrenia spectrum. However, it is unclear whether associations between semantic processing measures and schizotypal traits are stable over time. The current study aimed to explore the temporal stability of semantic processing measures and their correlations with schizotypal traits. In this study, we used the Schizotypal Personality Questionnaire (SPQ) to assess schizotypal traits and explored the association between schizotypal traits and semantic processing measures (i.e., N400- a large negativity with a broad scalp distribution, peaking around 400 ms after the presentation of any potentially meaningful stimulus) at baseline (Time 1; n = 63) and 3 months later (Time 2; n = 44). Repeated-measure ANOVA was conducted to examine the stability of the semantic processing measures; the intraclass correlation coefficient (ICC) was used to examine test-retest reliability; Pearson's r was calculated to explore associations between schizotypal traits and semantic processing measures. Results showed that both behavioral (reaction times) and N400 measures showed high reliability but low temporal stability. N400 latency for semantically unrelated stimuli was correlated with the cognitive-perceptual and the disorganized dimensions of schizotypal traits at Time 2. In conclusion, semantic processing measures generally showed good reliability. Schizotypal traits were correlated with N400 latencies in the current sample, but further studies are needed to examine whether this association is stable.