Imaging Neurosci (Camb)
January 3, 2025
Kenneth Shinozuka, Prejaas K.b. Tewarie, Andrea I. Luppi et al.
9 citations
LSD weakens the brain's usual hierarchy of information flow by making neural communication more balanced between sending and receiving signals. Using magnetoencephalography (MEG) data from 16 healthy adults given 75 micrograms of LSD intravenously, researchers measured directed functional connectivity under four conditions (eyes-closed with or without music, eyes-open with or without video). Across the whole brain, LSD reduced the asymmetry of directed connectivity over time. Machine learning classifiers distinguished LSD from placebo more accurately using hierarchy metrics than traditional connectivity measures. These results indicate that LSD flattens the brain's hierarchical information processing by increasing the balance between senders and receivers of neural signals.
bioRxiv (Cold Spring Harbor Laboratory)
April 28, 2024
Kenneth Shinozuka, Prejaas K.b. Tewarie, Andrea I. Luppi et al.
5 citations
preprint
LSD weakens the brain's directed connectivity hierarchy by increasing the balance between senders and receivers of neural signals. This finding supports the REBUS theory, which proposes that psychedelics flatten the hierarchy of information flow in the brain. Analyzing magnetoencephalography data from 16 healthy participants given 75 micrograms of intravenous LSD, the study found that LSD diminishes the asymmetry of directed connectivity averaged over time. Machine learning classifiers distinguished LSD from placebo more accurately when trained on hierarchy metrics than on traditional functional connectivity measures.
bioRxiv Preprint Server
February 11, 2025
Saketh Malipeddi, Arun Sasidharan, Rahul Venugopal et al.
2 citations
preprint
Meditation alters brain activity, particularly in alpha and theta frequency bands, but most research has focused on average power changes from rest to meditation rather than how quickly these changes emerge. This gap means little is known about the time-to-onset and temporal dynamics of neural shifts during meditation practice.
Communications Biology
June 12, 2026
Saketh Malipeddi, Arun Sasidharan, Bianca Ventura et al.
Advanced meditators from the Isha Yoga tradition report stronger non-dual experiences—where the boundary between self and environment dissolves—during breath-watching meditation compared to novices and meditation-naïve controls. Using EEG-based intrinsic neural timescales (INT), researchers found that across all participants, INTs are longer during internal attention (breath-watching) than during an external cognitive task. However, advanced meditators show similar INT durations between internal and external attention, and this reduced difference correlates with stronger reported non-dual experiences. The findings suggest that similar intrinsic neural timescale durations across internal and external attention may be a neural signature of non-duality.
Brain Communications
January 1, 2026
Sven Stuiver, Prejaas K.b. Tewarie, Julia C M Pottkämper et al.
After a generalized seizure induced by electroconvulsive therapy, recovery of self-orientation—the ability to report one's own identity—depends on restoration of effective communication between the cortex and thalamus. Analysis of 345 EEG recordings from 33 patients showed that immediately after seizure termination, the thalamus suppressed the cortex with minimal intrinsic activity. During recovery, cortical gain decreased while corticothalamic and intrathalamic gains increased, reflecting progressive restoration of thalamic excitatory drive. Self-orientation was regained when model parameters converged to a characteristic regime, with relatively small variability across patients, suggesting a critical threshold for re-emergence of reportable consciousness.