Your Brain on Shrooms

Shown here are the effects of psilocybin that the researchers observed. Regions labeled in blue indicate a decrease in brain activity. Many people have either had or heard of mind-bending experiences attributable to psilocybin — so if you or someone you know has experimented with mushrooms, the fact that the researchers’ observations reflected a decrease in brain activity during a trip will probably strike you as odd. What’s going on here, man?

“Psychedelics are thought of as ‘mind-expanding’ drugs, so it has commonly been assumed that they work by increasing brain activity. Surprisingly, we found that psilocybin actually caused activity to decrease in areas that have the densest connections with other areas.”

Did you catch that? The most important thing to take away from this study isn’t the fact that brain activity decreased, it’s where the activity decreased. The greatest dips in activity were observed in regions of the brain known as the medial prefrontal cortex (mPFC) and the anterior and posterior cingulate cortices (ACC and PCC, respectively). And as if that wasn’t enough, the researchers’ findings also suggest that psilocybin takes its disabling effects one step further by disrupting connections between the mPFC and PCC.

You can think of your mPFC, PCC, and a third region of your brain called the thalamus, as transportation hubs that coordinate the flow of information throughout your brain. Decreased activity within and between the brain’s hubs allows for “an unconstrained style of cognition.”

What the hell does that mean? Mo Costandi fleshes things out for us, with a little help from Aldous Huxley:

In his 1954 book The Doors of Perception, novelist Aldous Huxley, who famously experimented with psychedelics, suggested that the drugs produce a sensory deluge by opening a “reducing valve” in the brain that normally acts to limit our perceptions.

The new findings are consistent with this idea, and with the free-energy principle of brain function developed by Karl Friston of University College London that states that the brain works by constraining our perceptual experiences so that its predictions of the world are as accurate as possible.

(via io9)

(Source: metaconscious, via illuminated-by-hate)