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Mushroom Tripping Is a Lot Like Dreaming, Biologically Speaking

New fMRI data shows increasing entropy in similar parts of the brain during trips and during dreams.
Image: Erik Fenderson

If you've done mushrooms, you already know this dream/trip linkage to be true, even if that knowledge doesn't come from fMRI brain scans. Tripping so often involves a kind of waking dream state, where ethereality becomes a feeling as physical as hunger or warmth. The world isn't such a confined place anymore, and time moves ecstatically, between burps and pauses. I can't really recommend it enough. The good news is that even the chemically-adverse among us experience something like tripping on a nightly basis in the form of dreams.


This similarty occurs in a very real, physiological way, a revelation that comes courtesy [of research](http://This similarty occurs in a very real, physiological way.) out this week from Imperial College London demonstrating remarkable similarities between the brain's functioning during dream states and trip states, at least as induced by the active compound in psychedelic mushrooms, psilocybin.

The experiment took 15 subjects and injected them with either psilocybin or some placebo as they lay inside the brain scanning machine. Using a marker called the blood oxygen level dependent signal (BOLD), the team was able to essentially make a map of brain activation under the drug's effects.

What they found was that, under the influence of psilocybin, the parts of the brain responsible for high-level thinking—self-awareness/consciousness, problem solving, decision making—become unsyncronized, leading to "disjointed and uncoordinated" brain activity, according to a statement from Imperial College. Meanwhile, a tripping brain also experiences increases in activity in more primitive regions of the brain, like those responsible for memory, emotion, and arousal; these regions get "louder." You can see the potential of such a combination of effects.

"I was fascinated to see similarities between the pattern of brain activity in a psychedelic state and the pattern of brain activity during dream sleep, especially as both involve the primitive areas of the brain linked to emotions and memory," said the College's Dr. Robin Carhart-Harris.


"People often describe taking psilocybin as producing a dreamlike state and our findings have, for the first time, provided a physical representation for the experience in the brain." The difference, of course, is that only one of these variations on tripping can be experienced awake around a campfire in some desert; a dream, relatively speaking, feels like random chance.

Carhart-Harris notes that this is hardly trivial research and understanding things like psilocybin in very high resolution is a pathway toward using them, possibly in therapeutic settings. "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," she said. "Psychedelics were used for therapeutic purposes in the 1950s and 1960s but now we are finally beginning to understand their action in the brain and how this can inform how to put them to good use."

The precise metric explored by the team is fascinating just in itself: entropy. Entropy, properly, is a measurement of the randomness possible in a given system, like the brain, sure, but more commonly in less squishy and less alive sorts of mechanical systems. Looking at the dosed brains, it was possible to look at specific neural networks in these terms: not what the brain is doing but what it is capable of doing.

So, the question is how many possibilities are available to a certain portion of the brain on mushrooms. In the brain's primitive regions, it appeared that more entropy was present, and so more possibilities. This, according to Carhart-Harris et al, might be likened to the "mind expansion" reported by mushroom users.

In somewhat more understated terms, entropy is a measurement of network complexity. And what complexity actually means in the brain is an evolving science. A study out earlier this year in the journal Frontiers of Human Neuroscience found that in normal, undrugged brains, increasing complexity within particular networks of the brain was correlated with less functional connectivity between networks across the whole brain, at least at "fine" grain time scales. So, the more one part of the brain looks inward, the less it looks outward. Mind expansion is a trade-off, it seems, but at "coarse" grain scales (larger, chunkier), complexity seems to have the opposite effect of inceasing syncronization. It really depends on the specific brain task.

"This pattern is most consistent with the proposal that neural complexity is related to the regulation of neural synchrony and with the ideas that that information processing is maximized when neurons desynchronize at fine time scales," the earlier study suggested. So, we can imagine the brain's tasks (or functions/methods) broken down into smaller and smaller bites, temporally speaking, and when they're very small, the brain desyncronizes, leaving individual networks to handle the processing.

But when the tasks get bigger, they're more likely to be swapped around. You could look then at the effect of mushrooms/dreaming as an overemphasis on specific regions of the brain. The experience of some feeling, like "love," gets amplified at the expense of self-awareness. Expansion and contraction, simultaneously. Does this mean that the love experienced in a trip is any less "you"? It's an interesting thought, at least.