Where is the mind with the brain? While there is no shortage of research on the effects of psychedelics, drugs like LSD have yet to teach us much about how the brain works and can shed light on the mysterious interface between consciousness and neuronal physiology.
In a new study investigating the effects of LSD on volunteers, scientists found that psychedelic allows the brain to function in a way beyond what the anatomy usually dictates, altering the states of dynamic integration and segregation. of the human brain.
“The psychedelic compound LSD induces a deeply altered state of consciousness,” explains Andrea Luppi, first author and researcher in neuroscience at Cambridge University.
“The combination of pharmacological interventions with noninvasive brain imaging techniques such as functional magnetic resonance imaging (fMRI) can provide information on normal and abnormal brain function.”
The new research is part of the study of dynamic functional connectivity: the theory that brain phenomena demonstrate states of functional connectivity that change over time, in the same way that our flow of consciousness is dynamic and always flows. .
When this happens, and the human brain processes the information, it must integrate this information into an amalgamated form of understanding, but at the same time segregate the information, keeping the different sensory flows separate, so that they can be manipulated by particular neural systems. .
This distinction, the dynamics of brain integration and segregation, is something that is affected by psychedelic drugs, and with the advent of brain imaging technology, we can observe what happens when our usual functional connectivity is seen. interrupted.
In the study, a group of 20 healthy volunteers underwent brain scans in two separate sessions, separated by fifteen days. In one session, participants took a placebo before entering the fMRI scanner, while in the other slot they were given an active dose of LSD.
By comparing the results of the two sessions, the researchers found that LSD disengages functional connectivity from the limitations of structural connectivity, while altering the way the brain manages the balance between information integration and segregation. .
“Our main finding is that the effects of LSD on brain function and subjective experience are not uniform over time,” says Luppi.
“In particular, the well-known feeling of ‘ego dissolution’ induced by LSD correlates with the reorganization of brain networks during a state of high global integration.”
In fact, the altered state of consciousness of the drug could be seen as an abnormal increase in the functional complexity of the brain, with data showing times when the brain revealed predominantly segregated patterns of functional connectivity.
In other words, the “dissolution of the ego” of a psychedelic journey could be the subjective experience of the brain taking on its segregation dynamics, detaching the brain structure from its functioning, that is, your ability. to integrate and amalgamate separate information flows into a unified whole. decreases.
“Therefore, it seems that LSD induces especially complex functional connectivity (HR) patterns by inducing additional HR decoupling of the underlying structural connectome, precisely during times when structural-functional coupling is already minimal,” the authors explain in your article. .
“Because of the effects of LSD, the brain is free to explore a variety of patterns of functional connectivity that go beyond those dictated by anatomy, presumably leading to unusual beliefs and experiences reported during the psychedelic state. “.
The findings are reported in NeuroImage.