id_992. NEURAL MARKERS OF SARCASM AND IRONY PROCESSING IMPAIRMENT IN SCHIZOPHRENIA: A BEHAVIORAL AND EEG-ERP STUDY
Wojciech Żukowski1, Ida Żyznowska1, Wiktor Więcławski1, Suvarna Chinta1, Piotr Błądziński2,3, Aneta Kalisz2,3, Andrzej Cechnicki2,3, Krzysztof Walczewski4,5, Łukasz Cichocki4,5, Andrzej Marycz5, Karolina Rataj6, Jakub Szewczyk1, Przemysław Adamczyk1
1 Institute of Psychology, Jagiellonian University, Krakow, Poland
2 Department of Community Psychiatry, Association for the Development of Community Psychiatry and Care, Krakow, Poland
3 Department of Biological and Community Psychiatry, Chair of Psychiatry and Psychotherapy, Jagiellonian University Medical College, Krakow
4 Clinic of Psychiatry, Andrzej Frycz Modrzewski Krakow University, Krakow, Poland
5 Babinski Clinical Hospital, Krakow, Poland
6 Neuroscience of Language Laboratory Department of Psycholinguistic Studies Faculty of English Adam Mickiewicz University, Poznań
INTRODUCTION: Schizophrenia is a complex psychobiological disorder, in which neurodevelopmental changes lead to psychosocial and communication impairments, as e.g. pragmatic use of irony and sarcasm. Recent data on irony and sarcasm processing in schizophrenia is very limited.
AIM(S): Yet our study attempts to provide deeper insight into the neural correlates of this phenomenon using behavioral and EEG-ERP methods.
METHOD(S): In behavior, we tested 89 schizophrenia patients (55M:34F, age 41±10.0) and 57 healthy controls (38M:19F, age 41±9.1). Participants rated comprehensibility and figurativeness of 120 stories in four conditions: irony (IRO), sarcasm (SAR), and literal (LIT) and absurd (meaningless ABS). In EEG we reported results from 50 patients (35M, 15F; age: 43±9.3) and 42 controls (27M, 15F; age: 42±8.3). who read another 120 stories in the same four conditions. A 64-channel EEG was recorded and preprocessed for ERP analysis using MathWorks MATLAB Automagic. Linear mixed-effects models were computed for each channel in the 300–500 ms (N400) and 500–700 ms (P600) windows.
RESULTS: Behavioral results showed that patients were less accurate than controls in identifying SAR, IRO, and LIT, but not ABS (p < .05). In EEG, N400 between-group differences were found for SAR on parietal, parieto-occipital, and occipital regions. P600 differences emerged for ABS over frontal and central sites, and for both IRO and SAR over centro-parietal, parietal, and occipito-parietal regions. Notably, patients exhibited a general suppression of neural activity across all conditions and almost all electrodes.
CONCLUSIONS: In conclusion, this study is the first to demonstrate EEG-ERP correlates of irony and sarcasm processing in schizophrenia. Altered N400 and P600 responses indicate disrupted detection and integration of non-literal meaning, pointing to neural mechanisms underlying pragmatic communication impairments. Our study offers unique and valuable insight into impaired pragmatic language processing in schizophrenia.
FINANCIAL SUPPORT: This study was supported by the National Science Centre Poland grant no. 2021/41/B/HS6/02967.