Resting-state degree centrality and Granger causality analysis of facial working memory in patients with first-episode schizophrenia

Abstract

Background: This study focused on the relationship between facial working memory (WM) and resting-state brain function abnormalities in patients with schizophrenia. Methods: Resting-state functional magnetic resonance imaging (rs-fMRI) data were collected from 28 first-episode schizophrenia (FSZ) patients and 33 healthy controls (HCs). Degree centrality (DC) and Granger causality analysis (GCA) were used to assessbrain region connectivity. A match-to-sample task was used to examine visual WM for faces and houses. Correlations between DC and facial WM scores were analysed. Brain regions were selected as regions of interest (ROIs) and subjected to further GCA. Result: The results revealed that WM accuracy was lower in FSZ patients than in HCs for both loads and stimuli (P < 0.010). FSZ patients presentedspecific facial WM impairmentsat high loads (t = 2.21, P = 0.031). DC values of the right middle frontal gyrus (MFG) were linked to facial WM accuracy (P < 0.050, FDR correction). GCA indicated inhibited connectivity from the right MFG to the right inferior frontal gyrus (IFG) and right thalamus and from the right postcentral gyrus to the right MFG in FSZ patients (P < 0.050, FDR correction). DC values of the right thalamus correlated with negative symptom scores (r = -0.44, P = 0.018) and affective symptom scores (r = -0.57, P = 0.002). Conclusions: Our findings suggest that FSZ patients may have specifically impaired facial WM ability, which may be associated with altered functions in multiple brain regions. Some of these functions are associated with clinical symptoms, which may provide insight into the underlying neural mechanisms of schizophrenia.