O5.3. IMPAIRED LEFT TEMPORAL-PARIETAL JUNCTION FMRI ACTIVITY DURING CATEGORY FLUENCY IN FIRST-EPISODE PSYCHOSIS

• Published in: Schizophrenia bulletin 2020-05, Vol.46 (Supplement_1), p.S11-S12
• Main Authors: Perumaly, Leana, Curtis, Mark, Fishel, Vanessa, Torrence, Natasha, Wang, Yiming, Seebold, Dylan, Farris, Rebekah, Coffman, Brian, Salisbury, Dean
• Format: Article
• Language: English
• Subjects: Oral Session: Digital Health/Methods
• ISSN: 0586-7614; 1745-1701
• DOI: 10.1093/schbul/sbaa028.026

Abstract Background Language impairments are a core feature of schizophrenia. Category fluency is severely impacted, even as early as the first-episode of psychosis (FEP). It remains unclear which brain regions in the early course of schizophrenia are dysfunctional during category fluency. Therefore, we investigated differences in fMRI bold activity during a category fluency task in FEP, with particular attention to left temporo-parietal junction (TPJ) and inferior frontal gyrus (IFG), areas critical to verbal fluency. Our hypothesis was that left TPJ would show overactivity in FEP due to functional dysconnectivity with IFG, thought to modulate TPJ activation. Methods Twenty-seven FEP and 25 matched healthy controls (HC) completed an overt category fluency task (animal naming) from the MATRICS Consensus Cognitive Battery (MCCB), and a covert category fluency task while BOLD fMRI was acquired. The fMRI task had a total of 10 blocks (30s duration) with two alternating conditions: category and rest. At the beginning of the category condition, a category name (birds, breeds of dogs, fruits and vegetables, fish, flowers and trees) was displayed on the screen, and individuals were instructed to think of items within that category. At the beginning of the rest condition, individuals were instructed to silently repeat the word “rest” to themselves. To isolate the activity related to category exemplar generation, the rest condition and the category condition fMRI data were contrasted using SPM12. An uncorrected cluster-defining primary threshold of p