Brain Abnormalities in Different Phases of Working Memory in Schizophrenia

Abstract

The current study aimed to examine both gray matter and functional activity changes in schizophrenia by combing both structural and task-related functional magnetic resonance imaging (fMRI). Nineteen patients with schizophrenia and 17 controls were recruited. The fMRI scan was performed while performing a working memory (WM) task. In terms of task performance, accuracy did not differ between groups, but there were significant differences in reaction time. Compared with controls, patients exhibited decreased functional activation in prefrontal areas, insula, lingual gyrus, and superior temporal gyrus during different phases of WM. The subcallosal cortex showed increased activation. Intriguingly, a structural-functional correlation was found in the left dorsolateral prefrontal cortex, anterior cingulate cortex, and subcallosal cortex in patients when performing high-load WM task. This study demonstrated both impaired gray matter volume and functional activation during WM in schizophrenia, suggesting structural and functional impairments. The structural-functional correlation in schizophrenia suggested that structural damage in schizophrenia might induce a decreased ability to modulate functional response in accordance with increasing task difficulty.

Shared and distinct brain fMRI response during performance of working memory tasks in adult patients with schizophrenia and major depressive disorder

“…In other studies stronger fMRI response in bilateral pre‐frontal cortex (PFC) including medial prefrontal cortex (MPFC), ACC, PCC, superior temporal cortex (STC), middle temporal cortex (MTC) and cuneus, and right occipital cortex and parahippocampus, and weaker fMRI response in bilateral DLPFC, right MPFC, insula, parietal cortex and ventral striatum and left posterior cerebellum, during performance of WM tasks by patients with SZ compared to HC have been reported (Glahn et al, 2005; Meyer‐Lindenberg et al, 2001; Van Snellenberg et al, 2016). In several studies, including a meta‐analysis (Van Snellenberg, Torres, & Thornton, 2006), a region of interest (ROI) analysis was performed specifically for DLPFC and found stronger fMRI response (Karlsgodt et al, 2009; Manoach et al, 2000; Potkin et al, 2009; Van Snellenberg et al, 2016), weaker fMRI response (Fan et al, 2019; Kaminski et al, 2020; Menon, Anagnoson, Mathalon, Glover, & Pfefferbaum, 2001; Pu et al, 2019) or no significant difference in fMRI response (Van Snellenberg et al, 2006) in patients with SZ compared to HC. Additionally, using independent component analysis (ICA), several fMRI studies of WM tasks have revealed significant alterations of fMRI response in patients with SZ relative to HC, which are either correlated or anti‐correlated with WM performance, including stronger fMRI response in bilateral superior frontal gyrus (SFG), PCC, insula, superior temporal gyrus (STG), inferior temporal gyrus, precuneus, parahippocampal gyrus, amygdala, putamen and cerebellum, left DLPFC, cingulate gyrus and inferior parietal lobule (IPL) (Chatterjee et al, 2019; Kim et al, 2009), and weaker fMRI response in bilateral dentate gyrus and cerebellum (Kim et al, 2009).…”

Altered Functional Connectivity of the Nucleus Accumbens Network Between Deficit and Non-deficit Schizophrenia

“…In the current study, the FC between BNAcc and LING was higher in both DS and NDS patients. The LING, which is located in the medial occipital lobe, is involved in visual processing and several cognitive functions ( 35 , 36 ). A previous longitudinal study reported a significant increase of gray matter volumes within the bilateral lingual gyrus in schizophrenia.…”

Altered Cerebellar-Cerebral Circuits in Patients With Type 2 Diabetes Mellitus

“…Several studies have found that the lingual gyrus and lateral temporal lobes participate in and maintain working memory processing ( Zamora et al, 2016 ; Moon and Jeong, 2017 ; Fan et al, 2019 ). A study on a similar diabetic population also reported an association between poor working memory in patients and disrupted connectivity of the occipital network anchored in the lingual gyrus ( Cui et al, 2016 ).…”

“…Based on the consistent results of structural and functional studies, we believe that altered cerebellum-cerebral ECN is mainly manifested in cross-projecting functional abnormalities in T2DM. Several studies have found that the lingual gyrus and lateral temporal lobes participate in and maintain working memory processing (Zamora et al, 2016;Moon and Jeong, 2017;Fan et al, 2019). A study on a similar diabetic population also reported an association between poor working memory in patients and disrupted connectivity of the occipital network anchored in the lingual gyrus (Cui et al, 2016).…”