Brain scans of people watching walls breath and air move, in other words under the affect psilocybin or magic mushrooms, have given researchers a detailed picture of how psychedelic drugs work. Two studies identify areas of the brain where activity is suppressed by psilocybin and the data suggests that the drug helps people to experience memories more vividly.
In one study, 30 healthy people were given intravenous doses of psilocybin while inside an MRI machine which measured the subsequent brain activity. Those scans showed that activity decreased in the medial prefrontal cortex (mPFC) and the posterior cingulate cortex (PCC). The function of these areas is debated among neuroscientists, but it is widely recognized that the PCC has a role in consciousness and self-identity. The mPFC is hyperactive in depression so the suppression by psilocybin may be responsible for the antidepressant effect.
The second study found that psilocybin enhanced recollections of personal memories. This suggests that the drug could be useful for some types of psychotherapy.
“Psychedelics are thought of as ‘mind-expanding’ drugs so it has commonly been assumed that they work by increasing brain activity, but surprisingly, we found that psilocybin actually caused activity to decrease in areas that have the densest connections with other area. These hubs constrain our experience of the world and keep it orderly. We now know that deactivating these regions leads to a state in which the world is experienced as strange,” said Professor David Nutt, from the Department of Medicine at Imperial College London and senior author of both studies. There are indications that psilocybin could have use as a therapeutic drug. Studies will continue.
Source: MedicalNewsToday, Proceedings of the National Academy of Sciences