N,N-dimethyltryptamine effects on connectome harmonics, subjective experience and comparative psychedelic experiences

Area of Science:

• Neuroscience
• Psychopharmacology
• Computational Neuroscience

Background:

• Understanding the brain's structure-function relationship is key to neuroscience.
• Psychedelics offer unique models to study neurotransmitter effects on perception, cognition, and consciousness.
• Brain function changes induced by psychedelics propagate across the structural connectome.

Purpose of the Study:

• To investigate the effects of N,N-dimethyltryptamine (DMT) on brain function within the context of the human connectome.
• To apply connectome harmonic decomposition to analyze psychedelic-induced alterations in brain activity.
• To explore the relationship between brain function changes and subjective experience intensity.

Main Methods:

• Utilized connectome harmonic decomposition, a framework analyzing brain function dependence on network structure.
• Administered N,N-dimethyltryptamine (DMT) to participants.
• Measured changes in the connectome harmonic repertoire and repertoire entropy over time.

Main Results:

• The connectome harmonic repertoire under DMT was significantly reshaped, similar to other psychedelics (psilocybin, LSD, ketamine).
• Repertoire entropy of connectome harmonics increased under DMT, mirroring effects of other psychedelics.
• Measures of energy spectrum difference and repertoire entropy of connectome harmonics correlated with subjective experience intensity in real-time.

Conclusions:

• DMT, like other psychedelics, alters brain function in a manner dependent on the structural connectome.
• Increased repertoire entropy and energy spectrum difference in connectome harmonics reflect psychedelic states.
• Connectome harmonic analysis provides a time-resolved index of subjective experience, highlighting a direct link between brain network dynamics and consciousness.