Distinct brain networks are able to communicate and connect more openly when the default mode network is inactive
Various scanning technologies that the Imperial College lab has used to map the tripping brain show that the specialized neural networks of the brain—such as the default mode network and the visual processing system each become disintegrated, while the brain as a whole becomes more integrated as new connections spring up among regions that ordinarily kept mainly to themselves or were linked only via the central hub of the default mode network. Put another way, the various networks of the brain became less specialized. Distinct networks became less distinct under the influence of psychedelics or during meditation, implying that they communicate more openly with other brain networks. The brain operates with greater flexibility and interconnectedness under psychedelics and meditation.
In a 2014 paper published in the Journal of the Royal Society Interface, the Imperial College team demonstrated how the usual lines of communications within the brain are radically reorganized when the default mode network goes off-line and a high-entropy state is allowed to rise. Using a scanning technique called magnetoencephalography, which maps electrical activity in the brain, the authors produced a map of the brains internal communications during normal waking consciousness and after an injection of psilocybin. In its normal low-entropy state, the brain’s various networks talk mostly to themselves, with a relatively few heavily trafficked pathways among them. But when the brain operates under the influence of psilocybin, thousands of new connections form, linking far-flung brain regions that during normal waking consciousness don’t exchange much information. In effect, traffic is rerouted from a relatively small number of interstate highways onto myriad smaller roads linking a great many more destinations. The brain appears to become less specialized and more globally interconnected, with considerably more intercourse, or “cross talk,” among its various neighborhoods.
There are several ways this temporary rewiring of the brain may affect mental experience. When the limbic system is allowed to communicate directly with the visual processing centers, it’s possible our wishes and fears, prejudices and emotions, begin to inform what we see—a hallmark of high-entropy states and a recipe for magical thinking. Likewise, the establishment of new linkages across brain systems can give rise to synesthesia, as when sense information gets cross-wired so that colors become sounds or sounds become tactile. Or the new links give rise to hallucination. The forming of still other kinds of novel connections could manifest in mental experience as a new idea, a fresh perspective, a creative insight, or the ascribing of new meanings to familiar things. The increase in entropy allows a thousand mental states to bloom, many of them bizarre and senseless, but some number of them revelatory, imaginative, and, at least potentially, transformative.
I believe that silencing the default mode network brings us into a state of Imprint vulnerability. Our left hemisphere unconsciously focuses on only a select few of the sensory signals it receives that it considers important. As the default mode network goes quite, the brain widens its field of attention and attends to signals the default mode network usually edits out. As the brain processes all this new information, there is an explosion of neurogenesis, and new programs may be imprinted onto these new neurons and neural pathways.
References
- Pollan, Micheal. (2018). How to Change Your Mind Chapter 5. The Neuroscience of Your Brain on Psychedelics (Location 4312). New York, NY: Penguin Random House.
Metadata
Type:🔴 Tags: Biology / Neuroscience / Biochemistry / Neurochemistry / Pharmacology Status:☀️