بخش 81

So it may be that some brains could stand to have a little more entropy, not less. This is where psychedelics come in. By quieting the default mode network, these compounds can loosen the ego’s grip on the machinery of the mind, “lubricating” cognition where before it had been rusted stuck. “Psychedelics alter consciousness by disorganizing brain activity,” Carhart-Harris writes. They increase the amount of entropy in the brain, with the result that the system reverts to a less constrained mode of cognition.*

“It’s not just that one system drops away,” he says, “but that an older system reemerges.” That older system is primary consciousness, a mode of thinking in which the ego temporarily loses its dominion and the unconscious, now unregulated, “is brought into an observable space.” This, for Carhart-Harris, is the heuristic value of psychedelics to the study of the mind, though he sees therapeutic value as well.

It’s worth noting that Carhart-Harris does not romanticize psychedelics and has little patience for the sort of “magical thinking” and “metaphysics” that they nourish in their acolytes—such as the idea that consciousness is “transpersonal,” a property of the universe rather than the human brain. In his view, the forms of consciousness that psychedelics unleash are regressions to a “more primitive” mode of cognition. With Freud, he believes that the loss of self, and the sense of oneness, characteristic of the mystical experience—whether occasioned by chemistry or religion—return us to the psychological condition of the infant on its mother’s breast, a stage when it has yet to develop a sense of itself as a separate and bounded individual. For Carhart-Harris, the pinnacle of human development is the achievement of this differentiated self, or ego, and its imposition of order on the anarchy of a primitive mind buffeted by fears and wishes and given to various forms of magical thinking. While he holds with Aldous Huxley that psychedelics throw open the doors of perception, he does not agree that everything that comes through that opening—including the “Mind at Large” that Huxley glimpsed—is necessarily real. “The psychedelic experience can yield a lot of fool’s gold,” he told me.

Yet Carhart-Harris also believes there is genuine gold in the psychedelic experience. When we met, he offered examples of scientists whose own experiences with LSD had supplied them with insights into the workings of the brain. Too much entropy in the human brain may lead to atavistic thinking and, at the far end, madness, yet too little can cripple us as well. The grip of an overbearing ego can enforce a rigidity in our thinking that is psychologically destructive. It may be socially and politically destructive too, in that it closes the mind to information and alternative points of view.

In one of our conversations, Robin speculated that a class of drugs with the power to overturn hierarchies in the mind and sponsor unconventional thinking has the potential to reshape users’ attitudes toward authority of all kinds; that is, the compounds may have a political effect. Many believe LSD played precisely that role in the political upheaval of the 1960s.

“Was it that hippies gravitated to psychedelics, or do psychedelics create hippies? Nixon thought it was the latter. He may have been right!” Robin believes that psychedelics may also subtly shift people’s attitudes toward nature, which also underwent a sea change in the 1960s. When the influence of the DMN declines, so does our sense of separateness from our environment. His team at Imperial College has tested volunteers on a standard psychological scale that measures “nature relatedness” (respondents rate their agreement with statements like “I am not separate from nature, but a part of nature”). A psychedelic experience elevated people’s scores.*

• • • SO WHAT DOES a high-entropy brain look like? The 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 DMN. Put another way, the various networks of the brain became less specialized.

“Distinct networks became less distinct under the drug,” Carhart-Harris and his colleagues wrote, “implying that they communicate more openly,” with other brain networks. “The brain operates with greater flexibility and interconnectedness under hallucinogens.”

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 the tide of entropy is allowed to rise. Using a scanning technique called magnetoencephalography, which maps electrical activity in the brain, the authors produced a map of the brain’s internal communications during normal waking consciousness and after an injection of psilocybin (shown on the following pages). In its normal state, shown on the left, the brain’s various networks (here depicted lining the circle, each represented by a different color) talk mostly to themselves, with a relatively few heavily trafficked pathways among them.

But when the brain operates under the influence of psilocybin, as shown on the right, 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 memory and emotion centers are 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 primary consciousness 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, as when the contents of my memory transformed my visual perception of Mary into María Sabina, or the image of my face in the mirror into a vision of my grandfather. 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—or any number of the bizarre mental phenomena people on psychedelics report. 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.

One way to think about this blooming of mental states is that it temporarily boosts the sheer amount of diversity in our mental life. If problem solving is anything like evolutionary adaptation, the more possibilities the mind has at its disposal, the more creative its solutions will be. In this sense, entropy in the brain is a bit like variation in evolution: it supplies the diversity of raw materials on which selection can then operate to solve problems and bring novelty into the world. If, as so many artists and scientists have testified, the psychedelic experience is an aid to creativity—to thinking “outside the box”—this model might help explain why that is the case. Maybe the problem with “the box” is that it is singular.