Reduced synchronized brain activity in schizophrenia during viewing of comedy movies

Pei-Chi Tu,Ya-Mei Bai,Wei-Chen Lin,Fa-Hsuan Lin,Tung-Ping Su,Wan-Chen Chang,Cheng-Ta Li

doi:10.1038/s41598-019-48957-w

Abstract

Previous evaluation of brain function in schizophrenia has focused on standard experimental tasks, with cerebral response to natural stimuli less clear. This study employed inter-subject correlation (ISC) analysis to investigate the neural basis of humor processing during free viewing of comedy movies in patients with schizophrenia. We recruited 29 patients diagnosed with schizophrenia and 29 healthy, age- and sex-matched controls. Each participant underwent fMRI scanning during two viewings of three comedy movie clips. The ISC map from each participant pair within each population group and each movie viewing was separately derived. The significance of ISC within a group and between two groups were assessed by bootstrapping. The ISC map from each patient pair were also correlated with the product of Positive and Negative Syndrome Scale (PANSS) rating between the same participant pair in schizophrenia patients. Schizophrenia patients showed significant ISC in bilateral lateraloccipital, bilateral superior frontal, left supramarginal, and right lateralorbiofrontal cortices. Compared with the controls, the schizophrenia group exhibited significantly lower ISC in the left superior temporal sulcus, bilateral supramarginal, and bilateral inferiorparietal cortices. Higher clinical severity (higher total PANSS rating) was associated with lower ISC in the middle frontal and middle temporal regions, and also higher ISC in the visual cortex, inferior temporal gyrus, and anterior cingulate. The findings indicated that patients with schizophrenia are characterized by lower ISC in a frontal parietal network while viewing comedy film clips, which implicated a deficit in the cognitive component of humor processing. The lower synchronization in parts of the frontal parietal network also correlated with symptom severity.

Highlights

Schizophrenia is a devastating psychiatric disorder accompanied by auditory hallucination, delusion, and cognitive impairment
The results indicated that the data-driven Inter-subject correlation (ISC) analysis revealed the same foci as the model-based General Linear Model (GLM) analysis
The present study investigated the neural correlates of humor processing in schizophrenia during viewing of comedy movie clips by using ISC analysis

Summary

Introduction

Schizophrenia is a devastating psychiatric disorder accompanied by auditory hallucination, delusion, and cognitive impairment. This effect was significantly correlated with the depression severity While these studies have provided evidence of the feasibility of the ISC method’s use for neuropsychiatric patients, the synchronization of schizophrenia patients’ brain activity when viewing naturalistic stimuli, to the best of our knowledge, has not been explored. We employed ISC analysis to investigate the neural processing of humor during the viewing of comedy movies in patients with schizophrenia. Two ISC studies have investigated the neural correlates of humor appreciation under natural conditions when viewing comedy movies. They discovered a consistent pattern of brain synchronization in the healthy participants. They discovered that such patients exhibited less sensitive humor detection, but their appreciation of humor was similar to the general population[15]

Methods

Results

Discussion

Conclusion