The chemical psilocybin causes the same brain activation as dreaming does (Image: Ryan Wendler/Corbis)

Anyone who has enjoyed a magical mystery tour thanks to the psychedelic powers of magic mushrooms knows the experience is surreally dreamlike. Now neuroscientists have uncovered a reason why: the active ingredient, psilocybin, induces changes in the brain that are eerily akin to what goes on when we’re off in the land of nod.

For the first time, we have a physical representation of what taking magic mushrooms does to the brain, says Robin Carhart-Harris of Imperial College London, who was part of the team who carried out the research.

Researchers from Imperial and Goethe University in Frankfurt, Germany, injected 15 people with liquid psilocybin while they were lying in an fMRI scanner. The scans show the flow of blood through different regions of the brain, giving a measure of how active the different areas are.


The images taken while the volunteers were under the influence of the drug were compared with those taken when the same people were injected with an inert placebo. This revealed that during the psilocybin trip, there was increased activity in the hippocampus and anterior cingulate cortex, areas involved in emotions and the formation of memories. These are often referred to as primitive areas of the brain because they were some of the first parts to evolve.

Primal depths

At the same time, decreased activity was seen in “less primitive” regions of the brain associated with self-control and higher thinking, such as the thalamus, posterior cingulate and medial prefrontal cortex.

This activation pattern is similar to what is seen when someone is dreaming.

“This was neat because it fits the idea that psychedelics increase your emotional range,” says Carhart-Harris.

Neuroscientific nuts and bolts aside, the findings could have genuine practical applications, says psychiatrist Adam Winstock at the South London and Maudsley NHS Foundation Trust. Psilocybin – along with other psychedelics – could be used therapeutically because of its capacity to probe deep into the primal corners of the brain.

“Dreaming appears to be an essential vehicle for unconscious emotional processing and learning,” says Winstock. By using psilocybin to enter a dreamlike state, people could deal with stresses of trauma or depression, he says. “It could help suppress all the self-deceiving noise that impedes our ability to change and grow.”

Next, the team wants to explore the potential use of magic mushrooms, LSD and other psychedelics to treat depression.

Journal reference: Human Brain Mapping, DOI: 10.1002/hbm.22562