LSD profoundly alters consciousness by reorganizing brain networks in specific frequency bands. Analyzing MEG data from 14 healthy participants, the substance enhances high alpha (12.1, 13.3 Hz) activity across all conditions and high beta (25.3 Hz) in three conditions, while suppressing low beta (18.1, 19.3 Hz) and low alpha (8.5 Hz). LSD also shifts network spatial distributions: low alpha moves anteriorly toward the motor cortex, high alpha becomes more localized to the visual cortex, and low beta expands over temporal and occipital cortices. These frequency- and region-specific changes add nuance to theories of network disintegration under psychedelics.
A single dose of the atypical psychedelic ibogaine can be highly effective at treating PTSD in veterans up to twelve months later, according to an observational study of 30 veterans. Using a novel EEG analysis method, researchers found that ibogaine shifted high-beta (24 and 25 Hz) brain networks from frontal areas toward posterior regions, an effect seen both three to four days and one month after treatment. This posterior shift correlated with improvements in PTSD symptoms and was replicated in an independent dataset on ibogaine for opioid use disorder. Neural modeling suggested the shift reflects increased corticocortical, not corticothalamic, connectivity. The reconfiguration of high-beta networks may be a robust biomarker for ibogaine's therapeutic effects.