Psychedelic drugs, or hallucinogens, are a group of drugs that can profoundly alter perception and cognition in the user, resulting in a so-called mind-expanding trip that is often associated with a vivid imagination and a dream-like state. But how do these drugs alter consciousness in such a way? While the psychedelic experience produced by these drugs is well documented, little was known about the behavior of the brain during these trips - until now.

In a recently published study, researchers investigated the effects of a psychoactive substance and found increased activity in regions of the brain that are known to be activated during dreaming. Interestingly, the opposite could be said for the brain network associated with higher-level thinking and self-consciousness, as the activity displayed here was dampened and disorganized. The team may therefore have finally provided a physical representation for the psychedelic experience. The study has been published in Human Brain Mapping.

In order to examine the biological basis for psychedelic drug trips, Imperial College London researchers enrolled 15 volunteers for the study and gave them either a placebo or psilocybin- the psychoactive ingredient of magic mushrooms. They also imaged the brains of the participants before, during and after the administration of the drug or the control using functional magnetic resonance imaging (fMRI).

They found that under the influence of psilocybin, brain activity was increased in the primitive network associated with emotion which includes the hippocampus and the anterior cingulate cortex. The hippocampus is associated with learning, memory and emotion, whereas the anterior cingulate cortex is associated with states of arousal. Interestingly, this activity closely resembles the brain activity observed during dreaming. Furthermore, they found dulled and unsynchronized activity in the networks from which we obtain our sense of “self.”

“Learning about the mechanisms that underlie what happens under the influence of psychedelic drugs can also help to understand their possible uses,” said co-author Dr. Carhart-Harris in a news-release. “We are currently studying the effect of LSD on creative thinking and we will also be looking at the possibility that psilocybin may help alleviate symptoms of depression by allowing patients to change their rigidly pessimistic patterns of thinking.”

Another interesting finding of this study was that the brains of individuals under the influence of psilocybin seemed to display a broader range of activity patterns in the emotion system. This therefore indicates that the participants had more potential brain states available to them, which is likely the biological basis for the “expansion” of consciousness that is so famously associated with psychedelic drugs.

While further research is warranted, the study is exciting because it provides, for the first time, an insight into the changes in brain dynamics that occur in mind-expanding drug trips.

[Via Imperial College London, The Conversation and Human Brain Mapping]