Choosing the reference electrode for EEG recordings substantially affects measures of brain activity, including the default mode network (DMN). Simulated data showed that the infinity reference obtained by the reference electrode standardisation technique (REST) exactly recovered the true network configuration. In real EEG data from 15 participants, different references—REST, average reference, linked mastoids, and left mastoid—produced significant differences in power spectra, coherence, and DMN connectivity. Compared with REST, the average reference strengthened long-distance connections between anterior and posterior brain areas, while linked mastoids and left mastoid references disrupted posterior connectivity. The effects depended on EEG frequency band. REST is a valid reference technique for objective comparisons across studies and clinical practice.
The default-mode network (DMN) in rats contains three coactive micropattern (CAMP) networks that show greater functional connectivity and efficiency than the original DMN structure across all states of consciousness. In the waking state, these three networks do not differ significantly in connectivity or network properties, but in two sleep states they exhibit distinct characteristics, suggesting each plays a specific role. Changes in the CAMP networks' connectivity and properties mirror those of the original DMN, indicating that different states of consciousness intrinsically affect DMN dynamics. These findings deepen understanding of how DMN functional connectivity alters during the sleep-wake cycle.
Internet addiction is linked to altered communication patterns across the whole brain. Individuals with internet addiction showed increased functional connectivity density in regions involved in cognitive control and the default mode network, including the right dorsolateral prefrontal cortex, left parahippocampal gyrus, cerebellum, bilateral middle cingulate cortex, and superior temporal pole. Decreased connectivity density appeared in the right inferior parietal lobe and bilateral calcarine and lingual gyrus, areas tied to visual attention. Scores on the Internet Addiction Test correlated with connectivity changes in the left parahippocampal gyrus and bilateral superior temporal pole. These patterns resemble those seen in substance addiction and share neurobiological features with attention deficit/hyperactivity disorder.