Parietal memory network and default mode network in first‐episode drug‐naïve schizophrenia: Associations with auditory hallucination

Abstract

Atypical spontaneous activities in resting-state networks may play a role in auditory hallucinations (AHs), but networks relevant to AHs are not apparent. Given the debating role of the default mode network (DMN) in AHs, a parietal memory network (PMN) may better echo cognitive theories of AHs in schizophrenia, because PMN is spatially adjacent to the DMN and more relevant to memory processing or information integration. To examine whether PMN is more relevant to AHs than DMN, we characterized these intrinsic networks in AHs with 59 first-episode, drug-naïve schizophrenics (26 AH+ and 33 AH−) and 60 healthy participants in resting-state fMRI. We separated the PMN, DMN, and auditory network (AN) using independent component analysis, and compared their functional connectivity across the three groups. We found that only AH+ patients displayed dysconnectivity in PMN, both AH+ and AH− patients exhibited dysfunctions of AN, but neither patient group showed abnormal connectivity within DMN. The connectivity of PMN significantly correlated with memory performance of the patients. Further region-of-interest analyses confirmed that the connectivity between the core regions of PMN, the left

Functional Connectivity Between Auditory and Medial Temporal Lobe Networks in Antipsychotic-Naïve Patients With First-Episode Schizophrenia Predicts the Effects of Dopamine Antagonism on Auditory Verbal Hallucinations

“…In general, the findings from the current study are consistent with the previously mentioned network models suggesting abnormal auditory cortex and MTL connectivity in individuals with AVHs. The current findings are also consistent with a few previous studies of ANFE schizophrenia with AVHs reporting aberrant connectivity of brain regions associated with auditory processing, language-related regions, internal monitoring, and memory ( 49 , 50 , 51 , 52 , 53 , 54 ), although a direct comparison with previous studies is not possible because of differences in clinical characteristics and connectivity measures. Moreover, increased connectivity between sensory networks and higher-order cognitive networks has been found in patients with AVHs across the psychosis spectrum, indicating that this effect is not specific to schizophrenia ( 55 ).…”

The Etiology of Auditory Hallucinations in Schizophrenia: From Multidimensional Levels

“…Within the auditory network, SZ-AH had lower interhemispheric connectivity in both primary and secondary auditory cortices when compared to SZ-non-AH (Gavrilescu et al, 2010). In another study, SZ-AH was reported to have decreased functional connectivity between two regions inside the auditory network, right Heschl gyrus, and right posterior superior temporal gyrus, compared to SZ-non-AH (Guo et al, 2020). Within the language network, SZ-AVH had higher functional connectivity of bilateral Wernicke's area with the left inferior frontal gyrus (Hoffman et al, 2011) and reduced causal interactions from the left inferior frontal gyrus to left middle temporal gyrus (Zhang et al, 2017).…”

“…Within the default mode network (DMN), SZ-AVH had lower effective connectivity from anteromedial prefrontal cortex to left inferior temporal gyrus and from posterior cingulate cortex to left cerebellum posterior lobe, inferior temporal gyrus, and right middle frontal gyrus than SZ-non-AVH (Zhao et al, 2018). Although Guo et al (2020) did not find dysconnectivity in the DMN, they reported that SZ-AH had reduced functional connectivity of overall parietal memory network adjacent to the DMN and also reduced functional connectivity between core regions, and the latter negatively correlated with AH severity.…”

Detecting Early Cognitive Decline in Alzheimer’s Disease with Brain Synaptic Structural and Functional Evaluation

“…the default mode (DMN) or medial-frontoparietal (one of many resting-state networks associated with self-directed cognitive processes such as introspection and autobio-graphic memory and characterised by low-frequency, spatially coherent brain activity at a low temporal frequency) [143,144]; • the salience (SN) or mid-cingulo-insular (which directs attention by identifying the vital event, thus preventing goal-driven engagement from being distracted by nonrelevant stimuli; it is active during attention, motivation, and executive function tasks. The SN acts as a "switch" that prevents simultaneous activation of DMN and control networks, i.e., it activates the control network and simultaneously deactivates the DMN to support efficient cognition) [145]; • the attention, i.e., dorsal-frontoparietal network (which controls the conscious focus, i.e., attention) [146];…”