CAMBRIDGE, United Kingdom — LSD, like most psychedelic drugs, has a reputation for altering a user’s state of consciousness. These “trips” change the way people see, hear, and even think about the world around them. Now, researchers from the University of Cambridge say they understand what LSD is doing to the human mind. Their study reveals that the drug actively changes the way the brain processes information, freeing it from the boundaries set by nature.
Gates Cambridge Scholar Andrea Luppi says LSD can serve as a powerful tool in understanding how a person’s mind utilizes the different functions of the brain. In a study on 20 volunteers, researchers examined brain scans from two separate experiments. The first involved a placebo, taken before undergoing an fMRI scan. Two weeks later, participants had another scan after taking a dose of LSD.
The results reveal LSD unties functional brain connectivity from the limits of normal, structural connectivity. This alters the way the brain balances integrating and segregating different pieces of information.
How does the brain process information?
Unlike structural connectivity, which focuses on the physical links between different regions of the brain, functional connectivity refers to various brain areas activating and interacting regardless of being connected. Dynamic functional connectivity is the theory that this relationship between separate brain regions changes over time; just like how a person’s stream of consciousness is always flowing and changing.
As humans receive new information, the brain goes to work blending all of it into a form the mind can understand. Some of that data gets segregated out, keeping certain streams of information separate from others so they can be handled by the proper neural systems.
When using LSD, study authors find the complexity of functional connectivity becomes abnormally high. There are moments where users experience mostly segregated patterns of functional connectivity. Basically, a psychedelic trip can untether the mind from working strictly according to which brain regions share a physical connection. The ability to blend and combine separate streams of information into one thought also seems to break down while using LSD.
“These results reveal a more nuanced, temporally-specific picture of altered brain connectivity and complexity under psychedelics than has previously been reported,” researchers say in a university release.
LSD can make users lose self-identity
Study authors add that hallucinogenic drugs can also cause users to experience “ego dissolution,” or completely losing the sense of personal identity. The MRI results reveal that this feeling ties into the restructuring of the brain while on a drug trip.
“The psychedelic compound LSD induces a profoundly altered state of consciousness. Combining pharmacological interventions with non-invasive brain imaging techniques such as functional MRI, can provide insight into normal and abnormal brain function,” Andrea explains. “From introspection, we know that the subjective stream of consciousness is a constant ebb and flow – so we explored the dynamic effects of LSD on human brain function, focusing on two key properties: integration and segregation of information in the brain.”
“Our main finding is that the effects of LSD on brain function and subjective experience are not uniform in time. In particular, the well-known feeling of “ego dissolution” induced by LSD correlates with reorganization of brain networks during a state of high global integration. These results reveal a new, dynamic dimension of psychedelic action on the human brain,” the researcher concludes.
The study appears in the journal Neuroimage.