Resting-state functional EEG connectivity in salience and default mode networks and their relationship to dissociative symptoms during NMDA receptor antagonism.
Level 3 - non-randomized controlled study
Non-randomized experimental pharmacological challenge study in healthy volunteers
PubMed 33385439 · doi:10.1016/j.pbb.2020.173092
What was done
Researchers measured resting-state source electroencephalographic (EEG) connectivity within and between the default mode network (DMN) and salience network (SN) in 21 healthy adult volunteers following administration of a subanesthetic dose of the NMDA receptor antagonist ketamine, alongside assessment of dissociative symptoms.
What was found
The abstract does not report specific numerical values, test statistics, or frequency bands. It reports that ketamine provoked dissociative symptoms and produced frequency-dependent increases and decreases in connectivity both within and between the DMN and SN.
Why it matters
The findings offer electrophysiological support for the NMDA receptor hypofunction model of schizophrenia, linking glutamate dysfunction to disrupted connectivity across large-scale intrinsic brain networks involved in self-referential processing and salience detection.
Limits
The study had a small sample size (n = 21) composed solely of healthy volunteers. The abstract does not indicate whether a placebo control, blinding, or randomization was used, nor does it provide quantitative effect sizes, frequency-specific metrics, or direct clinical comparisons to patients with schizophrenia.
Cited by
- context Brain imaging of the default mode network shows schizophrenia and significant dissociative disorders have a loose electrical patterning compared to obsessive ruminative states.