"What was most remarkable about the research is that the degree of ego dissolution reported by the participants correlated with a specific neural transformation. To get through the pragmatics of day-to-day life and the demands of survival, brain activity naturally differentiates itself into several distinct networks, each responsible for a particular cognitive function.
The three networks most closely examined by these scientists include a network for paying attention to what’s most salient, a network for problem-solving, and a network for reflecting on one’s own past and future. There is also a natural segregation between high-level (abstract) cognitive areas and low-level (concrete) perceptual areas, most notably the visual cortex. These distinctions are thought to be an essential design feature of a functional human brain.
The impact of LSD was to diminish connections within each of these networks, relaxing the bonds that kept them intact and distinct, while increasing the cross-talk among them. In other words, the normal etiquette of the brain requires segregation among networks that have different functions, and that etiquette was blown to bits.
Now most parts of the brain were communicating with most other parts of the brain. Concrete sensory experiences, like vision, intermingled with cognitive abstraction, and cognitive abstractions reshaped visual imagery. Perhaps that’s what explains the intricate fractal elaboration that people see in the branches of a bush while tripping on acid. The perception of salience and refinement of a sense of self are hashed together like potatoes and gravy. The brains and their owners no longer distinguish between what is most important, how to get stuff done, and who in fact is the arbiter of the importance of the stuff that needs to be done."--Guardian.