Where does the mind ‘meet’ the brain? There is no shortage of research on the effects of psychedelics, but drugs like LSD still have much to teach us about the functioning of the brain – and it may shed some light on the mysterious interface between consciousness and neural physiology, research shows on.
In a new study examining the effects of LSD on volunteers, scientists found that the psychedelic brain enables it to function beyond what anatomy normally determines, by altering conditions of dynamic integration and segregation in the human brain.
“The psychedelic compound LSD causes a profoundly altered state of consciousness,” explains the first author and neuroscience researcher Andrea Luppi of the University of Cambridge.
“The combination of pharmacological interventions with non-invasive brain imaging techniques such as functional MRI (fMRI) can provide insight into normal and abnormal brain function.”
The new research falls within the study of dynamic functional connectivity – the theory that brain phenomena demonstrate conditions of functional connectivity that change over time, in the same way that our stream of consciousness is dynamic and always flowing.
As this happens and the human brain processes information, it must integrate that information into an amalgamated form of understanding – but at the same time it must also separate information, and keep separate sensory currents apart so that it can be handled by particular neural systems.
This distinction – the dynamics of brain integration and segregation – is influenced by psychedelic drugs, and with the advent of brain imaging technology, we can see what happens when our regular functional connectivity is disrupted.
In the study, a group of 20 healthy volunteers underwent brain scans in two separate sessions, two weeks apart. In one of the sessions, participants took a placebo before entering the fMRI scanner, while in the other slot, they received an active dose of LSD.
In comparing the results of the two sessions, the researchers found that LSD extracts functional connectivity from the limitations of structural connectivity, while at the same time changing the way the brain handles the balance between handling and integrating information.
“Our main finding is that the effects of LSD on brain function and subjective experience are not timely,” says Luppi.
“In particular, the familiar feeling of ‘ego dissolution’ induced by LSD correlates with brain network reorganization during a state of high global integration.”
In effect, the state of altered consciousness of the drug can be seen as an abnormal increase in the functional complexity of the brain – with the data showing moments where the brain reveals mainly segregated patterns of functional connectivity.
In other words, the ‘ego-dissolution’ of a psychedelic journey can be the subjective experience of your brain that increases the segregation dynamics, which decouples the brain structure from functioning, which means you have the ability to integrate separate streams of information and to merge into a unified whole. becomes reduced.
“LSD seems to induce particularly complex patterns of functional connectivity (FC) by causing additional decoupling of FC from the underlying structural connection, especially during times when structural-functional coupling is already at its lowest,” the authors explain in their paper. . .
“Because of the effects of LSD, the brain is free to explore a variety of functional connection patterns that go beyond those prescribed by anatomy – which is likely to lead to the unusual beliefs and experiences reported during the psychedelic condition.”
The findings are presented in NeuroImage.