The default mode network (DMN), a set of brain regions more active at rest than during demanding tasks, shows abnormal hyperactivation and hyperconnectivity in schizophrenia and depression. In schizophrenia, this may contribute to excessive self-reference and problems with attention and working memory. In depression, DMN hyperactivity may underlie negative rumination. Greater DMN suppression in healthy brains is linked to better performance on attention-focused tasks. The review considers these findings in relation to the DMN's psychological functions and its alteration across various neuropsychiatric disorders.
Resting-state brain networks may help explain hallucinations across different sensory modalities and populations. This report from the International Consortium on Hallucination Research reviews evidence linking resting-state alterations to auditory hallucinations, finding connectivity differences in left-hemisphere auditory and language regions, plus atypical interactions of the default mode network with networks for cognitive control and salience. Similar patterns appear in visual hallucinations, suggesting both domain-general and modality-specific network changes. However, high methodological heterogeneity across studies limits direct comparisons. The authors offer recommendations for future research on resting-state connectivity and hallucinations.