Full Program »
177. Semantic search in psychosis: Cue salience, timing, and cognitive correlates
Impairments in category verbal fluency task (VFT) performance have been widely documented in psychosis. VFT research indicates that individuals tend to produce bursts of semantically related words in patterns similar to animals searching for food, suggesting a relationship between physical and cognitive foraging. While research using various hand-coded designations of semantic clusters and switches have found altered search patterns in psychosis, results have been inconsistent. Therefore, automated approaches that objectively quantify semantic similarity are warranted. In this study, individuals with schizophrenia (SZ; n=21), schizotypal personality disorder (SPD; n=25), and healthy controls (HC; n=40) performed VFT with “animals” as the cue. Computational model Word2Vec computed cosine-based semantic similarities between words based on co-occurrence in a large text corpus. Linear regressions examined diagnostic predictors of VFT performance, search cues, and timing. Results indicated that the SPD group was similar to HCs in all measures. In comparison to HCs, the SZ group had decreased VFT performance, heightened global search cue salience indicating a selection of more frequently occurring words upon entering a new semantic patch, and a smaller distinction in time spent searching between versus within semantic patches. These findings suggest alterations in search strategies and a less modular semantic network in schizophrenia.