How to Change Your Mind: What the New Science of Psychedelics Teaches Us About Consciousness, Dying, Addiction, Depression, and Transcendence

by Michael Pollan

It stands to reason that by quieting the brain network responsible for thinking about ourselves, and thinking about thinking about ourselves, we might be able to jump that track, or erase it from the snow.

The default mode network appears to be the seat not only of the ego, or self, but of the mental faculty of time travel as well. The two are of course closely related: without the ability to remember our past and imagine a future, the notion of a coherent self could hardly be said to exist; we define ourselves with reference to our personal history and future objectives. (As meditators eventually discover, if we can manage to stop thinking about the past or future and sink into the present, the self seems to disappear.)

Mental time travel is constantly taking us off the frontier of the present moment. This can be highly adaptive; it allows us to learn from the past and plan for the future. But when time travel turns obsessive, it fosters the backward-looking gaze of depression and the forward pitch of anxiety. Addiction, too, seems to involve uncontrollable time travel. T...

To say the default mode network is the seat of the self is not a simple proposition, especially when you consider that the self may not be exactly real. Yet we can say there is a set of mental operations, time travel among them, that are associated with the self. Think of it simply as the locus of this particular set of mental activitie...

autobiographical or experiential self: the mental operation responsible for the narratives that link our first person to the world, and so help define us. “This is who I am.” “I don’t deserve to be loved.” “I’m the kind of person without the willpower to break this addiction.”

Getting overly attached to these narratives, taking them as fixed truths about ourselves rather than as stories subject to revision, contributes mightily to addiction, depression, and anxiety. Psychedelic therapy seems to weaken the grip of these narratives, perhaps by temporarily disintegrating the parts of the default mode network where they operate.

And then there is the ego, perhaps the most formidable creation of the default mode network, which strives to defend us from ...

When all is working as it should be, the ego keeps the organism on track, helping it to realize its goals and provide for its needs, notably for survival and reproduction. It gets the job done. But it is also fundamentally conservative. “The ego keeps us in our grooves,” as Matt Johnson puts it. For better and, sometimes, for worse. For occasionally the ego can become tyrannical and turn its formidable powers on the rest of us.* Perhaps this is the link between the various forms of me...

‘the mind being an excellent servant but a terrible master.’

Consider the case of the mystical experience: the sense of transcendence, sacredness, unitive consciousness, infinitude, and blissfulness people report can all be explained as what it can feel like to a mind when its sense of being, or having, a separate self is suddenly no more.

Is it any wonder we would feel one with the universe when the boundaries between self and world that the ego patrols suddenly fall away?

Because we are meaning-making creatures, our minds strive to come up with new stories to explain what is happenin...

The predictive brain is getting so many error signals that it is forced to develop extravagant new interpretations of an experience that transcends its capacity for understanding.

Now I’m inclined to think a much better and certainly more useful antonym for “spiritual” might be “egotistical.”

Self and Spirit define the opposite ends of a spectrum, but that spectrum needn’t reach clear to the heavens to have meaning for us.

When the ego dissolves, so does a bounded conception not only of our self but of our self-interest. What emerges in its place is invariably a broader, more openhearted and altruistic—that is, more spiritual—idea of what matters in life. One in which a new sense...

It was Brewer, you’ll recall, who discovered that the brains of experienced meditators look much like the brains of people on psilocybin: the practice and the medicine both dramatically reduce activity in the default mode network.

The posterior cingulate cortex is a centrally located node within the default mode network involved in self-referential mental processes. Situated in the middle of the brain, it links the prefrontal cortex—site of our executive function, where we plan and exercise will—with the centers of memory and emotion in the hippocampus.

The PCC is believed to be the locus of the experiential or narrative self; it appears to generate the narratives that link what happens to us to our abiding sense of who we are.

activity in the PCC is correlated not so much with our thoughts and feelings as with “how we relate to our thoughts and feelings.”

When we take something that happens to us personally? That’s the PCC doing its (egotistical) thing.

Buddhists believe that attachment is at the root of all forms of mental suffering; if the neuroscience is right, a lot of these attachments have their mooring in the PCC, where they are nurtured and sustained.

by diminishing its activity, whether by means of meditation or psychedelics, we can learn “to be with our thoughts and cravings without getting caught up in them.”

Achieving such a detachment from our thoughts, feelings, and desires is what Buddhism (along with several other wisdom traditions) teaches is...

Take it personally, in other words. This is precisely the thought process that the PCC exists to perform, relating thoughts and experiences to our sense of who we are.

Next Brewer asked me to do a “loving-kindness” meditation. This is one where you’re supposed to close your eyes and think warm and charitable thoughts about people: first yourself, then those closest to you, and finally people you don’t know—humanity at large.

but we remain a long way from understanding exactly what happens to consciousness when we alter it, either with a molecule or with meditation.

Quantum mechanics holds that matter may not be as innocent of mind as the materialist would have us believe. For example, a subatomic particle can exist simultaneously in multiple locations, is pure possibility, until it is measured—that is, perceived by a mind.

The implication here is that matter might not exist as such in the absence of a perceiving subject. Needless to say, this raises some tricky questions for a materialist understanding of consciousness. The ground underfoot may be much less solid than we think.