Research into consciousness has been gaining ground lately, but the majority of the studies have revolved around the loss of consciousness: sleep, anesthesia, and coma. A recent paper delves into LSD’s impact on consciousness in the waking brain – and the results are unexpected.
Research recently published in the journal NeuroImage shows that LSD allows the normally strict neuronal pathways in the brain to become more flexible, allowing the brain to explore and make connections separate from those that are typically allowed by brain structure.
“In general, integration and segregation of information are fundamental properties of brain function: we found that LSD has specific effects on each,” says Andrea Luppi, Ph.D. candidate at the University of Cambridge and lead author of the study. “We also know that brain structure has a large influence on brain function under normal conditions. Our research shows that under the effects of LSD, this relationship becomes weaker: function is less constrained by structure.
This is largely the opposite of what happens during anesthesia.”
Luppi’s team examined data collected by Dr. Robin Carhart-Harris and Dr. Leor Roseman from the Centre for Psychedelic Research at Imperial College London for a separate study. The data included functional magnetic resonance imaging (fMRI) that examined brain activity in 20 volunteers. Volunteers underwent two MRI sessions, one after taking a placebo and one after taking 75 micrograms of LSD.
MRI results showed marked changes in the typical segregation and integration of stimuli in areas of the brain that normally do not interact. “Reduced similarity between structural and functional connectivity indicates that under the effects of LSD, brain regions interact functionally in a way that is less constrained than usual by the presence or absence of an underlying anatomical connection,” researchers wrote in the study.
These new interactions explain the dramatic altered consciousness one experiences after consuming LSD. “Being less constrained by pre-existing priors due to the effects of LSD, the brain is free to explore a variety of functional connectivity patterns that go beyond those dictated by anatomy – presumably resulting in the unusual beliefs and experiences reported during the psychedelic state, and reflected by increased functional complexity,” reads the study.
“Studying psychoactive substances offers a unique opportunity for neuroscience: we can study their effects in terms of brain chemistry, but also at the level of brain function and subjective experience,” says Luppi. “In particular, the mind is never static, and neither is the brain: we are
increasingly discovering that when it comes to brain function and its evolution over time, the journey matters just as much as the destination. A more thorough characterization of how psychedelics influence the brain may also shed light on potential clinical applications – such as the ongoing research at the new Centre for Psychedelic Research in London.”
This research was a collaborative effort between Luppi and Dr. Robin Carhart-Harris and Dr. Leor Roseman from the Centre for Psychedelic Research at Imperial College London, who collected and shared the data and was supervised by Dr. Emmanuel Stamatakis from the Cognition and Consciousness Imaging Group at the University of Cambridge.