The Neurodynamic Organization of Modality-Dependent Hallucinations
Cerebral Cortex April 24, 2012 Renaud Jardri, Pierre Thomas, Christine Delmaire et al. 180 citations
Hallucinations in psychosis may arise when the brain's default-mode network (DMN) disengages abnormally, similar to its response to real external stimuli. In 20 drug-free adolescents with brief psychotic disorder, multimodal MRI showed that during auditory, visual, and multisensory hallucinations, cortical thickness was reduced and blood oxygen level-dependent signal increased in modality-dependent association sensory cortices, while primary sensory cortex recruitment was not systematic and linked to greater vividness. DMN disengagement coincided with hallucinations, and spatial and temporal instabilities of the DMN correlated with hallucination severity and persisted even without symptoms. This suggests hallucinations emerge from spontaneous DMN withdrawal, offering a model beyond the auditory modality.