New research suggests that taking psilocybin, the hallucinogen in magic mushrooms, may actually lead to a decrease in the amount of blood flow in certain parts of your brain. Scientists at Imperial College London injected subjects with psilocybin and scanned their brains. Turns out, they observed a reduction in neuronal activity and blood flow in core regions of the brain like the thalamus and cingulate cortex. From Science News:

"Decreasing the activity in certain hubs in the network may allow for a more unconstrained conscious experience," says Matthew Johnson, an experimental psychologist at Johns Hopkins University School of Medicine in Baltimore who studies psilocybin and other hallucinogens. "These drugs may lift the filters that are at play in terms of limiting our perception of reality."

Further work by (Imperial College London) neuropsychopharmacologist David) Nutt's team showed that the brain hubs responded together, linked by a neural circuit called the default mode network. Some scientists believe this highly interconnected brain superhighway is essential for maintaining a person's sense of self.

Putting the brakes on this network could help to treat certain psychological conditions by opening the brain to new ways of thinking, researchers hope. Several studies have shown that psilocybin can change people's attitudes for the better and may be useful for treating depression, a condition linked to too much activity in the default mode network.

"Chemically switching off might have very profound beneficial effects," says Nutt, who suspects that psilocybin could also be useful for treating obsessive-compulsive disorder. "It may help people completely locked into a mindset that drives their lives."