id_800. ARE YOU KIDDING ME? NEURAL CORRELATES OF IMPAIRED HUMOR PROCESSING IN SCHIZOPHRENIA – A BEHAVIORAL AND EEG-ERP STUDY
Przemysław Adamczyk1, Ida Żyznowska1, Wojciech Żukowski1, 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
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, Poland
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, Poland
INTRODUCTION: Individuals with schizophrenia commonly exhibit impairments in the pragmatic use of humor, yet neural evidence remains scarce.
AIM(S): To address this gap, we aimed to differentiate EEG-ERP brain responses to two types of humor: intended-to-be-funny (kids) and social norm–violating (adults) jokes in individuals with schizophrenia and healthy controls.
METHOD(S): The behavioral study included 89 patients with schizophrenia (55M, 34F; age: 41±10.0) and 57 healthy controls (38M, 19F; age: 41±9.1), who rated the comprehensibility and figurativeness of 120 stories in four conditions: intended-to-be-funny (IFJ), social norm–violating (SVJ), and their literal (LIT) and nonsensical (ABS) control counterparts in a punchline-based humor comprehension task. EEG results are reported for 50 patients (35M, 15F; age: 43±9.3) and 42 controls (27M, 15F; age: 42±8.3). Participants read another 120 stories in a punchline-based humor reading task. 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 lower scores for IFJ, SVJ, and LIT, but not for ABS, in the clinical group (p<0.002). In EEG, N400 differences at parieto-occipital sites were found for SVJ and IFJ. At P600, the groups differed across all conditions over centro-parietal and parieto-occipital regions, with additional fronto-central differentiation for ABS and SVJ.
CONCLUSIONS: In conclusion, our results provide novel insight into the neural underpinnings of humor-processing impairment in schizophrenia. The diminished N400 suggests a reduced efficiency in incongruity detection and further attenuation of its resolution at P600. Together with behavioral results, our findings indicate less effective context integration processing in schizophrenia. In summary, this study offers a unique characterization of humor processing in neurotypical and clinical populations.
FINANCIAL SUPPORT: This study was supported by the National Science Centre Poland grant no. 2021/41/B/HS6/02967.