What the New Science of Psychedelics Teaches Us About Consciousness, Dying, Addiction, Depression, and Transcendence

By: Michael Pollan

Published: 2018

Read: 2019

Summary:

Over the past two decades, science has renewed its interest in the potential benefits of “psychedelic therapy” for a wide variety of mental disorders, after the large moral panic about LSD at the end of the 60s shut down previous research efforts in this area.

Early stage research shows that psychedelic therapy can be remarkably successful in reducing anxiety in dying cancer patients and resolving smoking and alcohol addiction; trials involving depression are underway. What these mental disorders may have in common is being trapped in cycles of negative thinking, restrictive narratives, rigid (self-referential) thought patterns and feeling cut off from the outside world.

A possible explanation for these shared characteristics of certain mental disorders involves a part of the brain called the default mode network (DMN), a higher level part of the brain’s cortex involved in self-directed attention (self-reflection, mind wandering, mental time travel, etc.).

The DMN, sometimes called the home of the “self”, is where we form our so-called “priors”: our beliefs about the world and ourselves. Priors play a central role in how we perceive, compress and (predictively) process incoming data from our senses to help us optimize our behavior in our daily lives. The DMN imposes order on the the brain and helps to maintain a coherent and consistent sense of self.

Disorders such as depression, anxiety and addiction may all be characterized by an overly active DMN, resulting in an excessive level of order and an associated rigidity and restrictiveness of thought.

Psychedelic therapy works by down-regulating the DMN, loosening the grip of prior beliefs and allowing the brain to explore previously suppressed information, to form different neural connections, and to generate potentially new perspectives or insights. While the psychedelic experience doesn’t last, some of its effects may endure over time or can be revisited through other means that similarly affect the DMN (for instance, meditation, breath-work or task-oriented activity).

The alternate state of consciousness brought about by the psychedelic experience provides an awareness that the normal, waking state of consciousness is not the only possible form and that it can be “tweaked”. While waking conscious is adaptive and helps us survive, the grooves of mental habits that form over time can sometimes become too deep and cause overly rigid and restrictive thinking. A helpful reminder to many, with or without mental problems, especially later in life.

Worth Reading:

A highly enjoyable exploration of the subject through a number of different intertwining narratives: historic, scientific and personal. I particularly enjoyed the chapter on the neuroscience behind psychedelics, which provided an introduction to many researchers that are doing groundbreaking work. Carhart-Harris in particular jumps out and his latest paper “REBUS and the Anarchic Brain: Toward a Unified Model of the Brain Action of Psychedelics” is very much worth reading.

The chapter on the history of psychedelic research may not be as interesting to everyone and I definitely got lost in the long list of characters that played a role in psychedelic research over the last 50-60 years.

Generally, this was a great example of how a journalistic approach to a subject can yield an entertaining story as well as honest, no-dog-in-the-race informative reporting. There are very few gotcha moments and it doesn’t feel like the author has any particular point to prove or a particular new paradigm to sell that narrative needs to be squeezed into. The book is all the more convincing because of this.

Practical Takeaways:

• The human brain is an uncertainty reduction machine.
• We start “wide” – as children, we have a “lantern” focus:
  • Disordered, widely diffused attention.
  • We search for less predictable, less likely answers.
  • High error rates, adaptation.
• As we adapt to our environment, we slowly develop “spotlight” focus:
  • Ordered, narrower focus on goals.
  • We search for more probable answers.
  • Lower error rates, preservation.
• Spotlight focus relies on “predictive coding” in the brain.
  • We develop a collection of coherent, stable beliefs (habits, biases).
  • We test these beliefs by using them to predict what will happen next.
  • Our objective is to minimize errors between our prediction and what we experience (ie, minimize surprises).
• This is our default mode of walking around.
  • It is efficient and optimized for survival.
  • It stimulates achievement (learn from the past, plan for the future).
• But sometimes, our beliefs and mental habits become too rigid …
  • Later in life the grooves of habit may become too deep.
  • Too conservative, no longer adaptive.
• … and result in maladaptive behaviors, or even mental disorders:
  • Narrow or fixed perspectives, behaviors and emotional repertoires.
  • Negative thinking (stuck in the past or worried about the future).
  • Inverse learning (repeating the same destructive thoughts or behavior, thereby reinforcing (unproductive) neural connections).
• It may then be beneficial to loosen the grip of our prior beliefs.
  • Through a temporary disturbance of predictive coding.
  • Reduction of activity in the brain’s default mode network (where many of our previously held beliefs reside).
  • Reduction of top-down control (beliefs).
  • Increased access to bottom-up signals.
• Resulting in potentially enduring benefits.
  • Flatten the grooves of habit.
  • Create new pathways of thought (insight, increased adaptation).
  • Broaden perspective beyond self-interest.
• Psychedelic therapy is one of the potential tools to do this.
  • Importance of set and setting (guided experience, prior intentions, post integration).
  • Other tools include meditation, breath work, task oriented behavior, etc.

Key Concepts:

Everyday, waking consciousness

• Default mode of conscious experience and perception.
• Predictive coding framework.
  • Evolved to help reduce uncertainty.
    • Uncertainty is the brain’s biggest challenge.
  • Develop educated guesses to predict and navigate the future.
    • Based on minimal incoming sensory data (compress).
    • Based on stored past experience.
  • Minimize errors by providing reliable predictions.
    • Continued reality testing (touching, memory, visual).
  • Optimize behavioral responses to environment.
    • Formulation of a set of prior beliefs and biases (the “ego”).
    • Familiar, habitual.
  • Save time and energy.
    • Jump to prediction based on small sample of data.
    • Bayesian inferences.
  • Best facilitates survival.
    • Forming a differentiated self, imposing order on anarchy of the primitive mind.
      • More efficient and reliable than primitive “magical thinking”.
    • Balancing top-down predictions with bottom-up sensory data.
  • May be limiting in other ways.
    • Grooves of mental habit may become too deep (especially later in life).
    • Overly reflexive behavior.
    • Fixed perspective on reality (of both outside world and own mind).

Not the only possible state of consciousness.

• Consciousness is weaving together our priors with the world’s data.
  • A form of controlled hallucination.
• Ordinary consciousness is one possible “window on reality”.
  • All conscious states are “imagined” versions of priors and data.
• Exploration of other states provides different perspectives on reality.
  • Through psychedelics, meditation, breath-work or other methods.
  • Experience of another way to react, or not to react.
  • Tempering of the ego.
  • Shift in perspective.
  • Restoring (child-like) immediacy of experience.

Alternate, “spiritual” states of consciousness:

• When the ego is muted or silenced.
• Four characteristics of alternate, “mystical” states of consciousness:
  • Ineffability.
    • Experience defies expression; no adequate report in words.
    • Transcendence of categories (time, space, self).
  • Noetic quality.
    • Significant and authoritative revelations and insights (sacredness, meaning).
      • Reclassification of the familiar.
      • Potentially banal and magical / unscientific.
      • May nevertheless be therapeutically helpful to the individual.
      • Platitudes and clichés experienced as hidden truths.
      • What was merely “known” before, is now felt.
  • Transiency.
    • Experience doesn’t last, but some of its effects do.
      • “Openness”.
      • Improved ability to handle uncertainty (negative capability).
  • Passivity.
    • Sense of surrender to a superior force.

Such as, the psychedelic experience:

• Open to both religious and materialist interpretations.
  • Materialist: experience can be traced back to impact of a chemical.
  • Religious: experience is proof of something “beyond”.
• May provide necessary behavioral variation (evolutionary perspective).
  • Rapidly changing environment.
  • Old behavioral patterns may no longer be adaptive.
  • Psychedelically induced variations may provide novel adaptations.
    • As well as many types of behavior that don’t work…
• Is highly “constructed”.
  • Expectancy effects are powerful.
  • Critical influence of set and setting:
    • Set: the mind-set or expectation one brings to the experience.
    • Setting: the environment in which it takes place.
  • Many complications in psychedelic therapy.
    • While suggestibility can help break destructive patterns of thought, provide new insights.
    • Many insights may be spoon fed (shamanism, placebo effect).
• Produces lasting changes.
  • In beliefs, attitudes and behavior.
• Stimulates creativity.
  • Helps to resolve complex problems by providing shifting perspectives, different patterns.
• Is a disruptive technology, challenging hierarchies.
  • Disrupting functional hierarchy inside the brain.
  • Challenges conventional belief systems and institutions.
  • Important to find the right context / container for the experience.
    • Steadying set of rituals, rules, protocols (guide, therapy).
• Is similar to meditation.
  • Relaxing the ego’s trigger-happy command of reactions to people and events.
    • Fewer reflexive reactions, less “self-interest”.
      • Moderating the urge to seek certainty.
      • Cultivating an ability to handle uncertainty.
    • Transcend subjectivity to widen circle.
      • Experiencing interconnectedness.

The neuroscience behind psychedelics:

• Tryptamines.
  • Organic compound.
  • Show up in plants, fungi and animals.
  • Type of signaling molecule.
    • Psychedelics: LSD, psilocin, 5-MeO-DMT.
    • Most famous one in humans: serotonin (5-hydroxytryptamine)
• Serotonin
  • Binds with a dozen or so different receptors.
  • Receptors found throughout the brain and the body (digestive tract).
• Brain chemistry.
  • Psychedelics have a strong affinity with one particular serotonin receptor.
    • 5-HT2AR.
    • Found in human cortex (most recent layer of our brain).
• Many 5-HT2AR receptors are found in the default mode network.

The default mode network (DMN)

• Part of the higher levels of the brain hierarchy.
  • “Keeps order”.
  • Exerts a top-down influence on other parts of the brain.
  • Links parts of the cerebral cortex to deeper and older structures (memory, emotion).
• Most active when we are engaged in higher level “meta-cognitive processes”.
  • Self-reflection, mental time travel, moral reasoning.
  • Seesaw relationship with the attentional networks in the brain.
    • When one is active, the other is quiet.
  • Home of the “wandering mind”.
• Helps to produce mental projections associated with the sense of “self”.
  • Composing the story of who we are by linking our past experience and our future goals.
    • Mental time travel is adaptive: learn from the past, plan for the future.
  • Not operational until late in child’s development.
• Evolved to help reduce uncertainty.
  • Develop priors to minimize surprise and uncertainty.
  • Impose order, coherent selfhood, capacity for mental reasoning.
  • Benefits: efficient, stimulates achievement, survival.
  • But, uncertainty reduction has its costs as well.
  • Constrains cognition and narrows consciousness.
    • Excessive rumination, separation from others and nature.
  • And can become pathological (hyperactive DMN).
    • Excess of order: grooves of self-reflection deepen and harden.
    • Uncontrollable introspection.
    • Excessively rigid patterns of thought (addiction, obsession, etc.)
• Develops later in life and acts to open or contract consciousness.
  • Adults: spotlight consciousness.
    • Ability to narrowly focus attention on a goal.
    • Direct your attention, rely on predictive coding to make sense of perception.
    • Low temperature searches (requiring little energy) – probable answers.
  • Young children: lantern consciousness.
    • Attention is more widely diffused.
    • Few priors guide perceptions down predictable tracks, awe, astonishment.
    • High temperature searches (requiring more energy) – less likely answers.
• Plays a central role in governing the degree of order / entropy in the brain.
  • Ability to handle degrees of uncertainty.
  • Brains have varying degrees of order / entropy.

Psychedelics reduce the activity in the DMN

• Causing an increase in the disorder of the brain.
  • Increase in entropy, level of disorder.
    • Ageing may represent a decline in entropy (forming deeper grooves of habit).
  • Loosening the grip of prior beliefs, or “ego”.
    • Loss of distinction between subject and object.
    • The usual boundaries between self and world fall away.
• Increasing activity in other brain regions.
  • Disinhibition of other areas of the brain, including limbic regions.
• Making available previously unavailable contents of the unconscious mind.
  • Old priors exert less influence.
    • Previously unavailable data becomes available.
  • Allowing new priors to form.
    • Trying to reduce uncertainty, formulating new stories, insights.
• Brain may slip back and forth.
  • Admitting new raw data.
  • Imposing new priors.
• Causing a variation of patterns of brain connections.
  • Increased variation:
    • “Shake the snow globe”.
      • New neural connections may provide aid to creative thinking.
  • Increased levels of interconnectedness.
    • Previously unconnected parts of the brain may connect.
  • Some of these connections may persist.
    • The awareness of newly formed pattern in the brain may persist.
      • For instance, the personality trait “openness” may change.
      • Strength of connections may depend on enforcement post experience (learning)
• Causing an expansion of consciousness.
  • Similar to childhood brain.
    • More “high temperature searches”.
    • More fluid thinking.
    • High error rates, high expansion of mental energy.
    • Explore entire space of possibilities.
• Potentially helpful for adaptation to new or rapidly changing environment.
  • While the system is “hot”.
    • High level of brain plasticity.
    • Variation: develop and entertain new ideas.
    • The species’ way of injecting noise into the system of cultural evolution.
  • System has to cool down:
    • Inefficient, can’t maintain high error rates, mental energy.
    • DMN kicks back in.
    • Consciousness narrows.
    • New insights may be preserved.

 Potential therapeutic applications

• “Psychedelic therapy” can be difficult to implement:
  • Difficulty of randomized controlled trials: impossible to blind, use placebo.
  • Difficult to separate chemical effect from the impact of set and setting.
  • Difficult to isolate relevant variables (context, therapist, patient).
• Mental disorders: a disorder of chemistry or a loss of meaning?
  • Psychedelics can potentially address both.
  • Potential to turn someone’s life (or death) in a positive direction.
• Mental disorder commonalities:
  • Tyranny of the ego.
    • A radical narrowing of one’s perspective, behavior and emotional repertoire.
    • Fixed narratives about relationship with the world.
  • Learned habits of negative thinking, trapped in loops of self-reflection, time travel:
    • Depression: stuck in the past.
    • Anxiety: worried about the future.
  • Inverse learning:
    • Repeating the same destructive thoughts or behavior reinforces neural connections.
• Linked to an overly active DMN.
  • Posterior cingulate cortex (PCC) within the DMN.
  • Uncontrollable time travel.
  • Overly attached to thoughts and feelings.
    • Linking what happens to you to your abiding sense of who you are.
    • Getting “caught up in our feelings”.
• Too much order.
  • The level of order in the brain is a continuum:
    • Too little: psychosis.
    • Too much: addiction, depression, anxiety.
• Psychedelics can reduce the impact of an overly active DMN.
  • Throw the brain into a more plastic (anarchic) state.
  • Flatten the grooves of habit.
  • Create new pathways (with the slightest nudge).
  • Broaden perspective beyond self-interest.
• Patients with the best outcomes are the ones with the most complete “mystical” experience.
  • Experiences such as “ego dissolution” don’t need supernatural explanations.
  • Most of the phenomenology can be explained materialistically:
    • Reduction in DMN activity drives feeling of ego-dissolution.
    • Reduction of rigid patterns of thoughts.
    • New insights, new meaning, less fear of uncertainty.
• Examples:
  • Depression, fear of death:
    • Overactive DMN.
      • Sense of disconnection, endless circles of rumination.
      • Suppressed emotions, restrictive emotional repertoire.
    • Psychedelics aids opening up, surrendering to previously suppressed emotions.
  • Addiction:
    • Addiction to patterns of thinking, with the self at the center of it.
    • Radical form of selfishness.
    • Wandering mind and firm existing priors reinforce addictive habits.
    • New insights under psychedelics become more compelling and harder to avoid.
    • Visualization (images): thoughts become visible, making experience more memorable.
• Psychedelics may be “awe” in a pill.
  • Awe is the emotion that makes us feel part of something larger than ourselves.
    • Directs attention away from the individual.
    • Promotes altruistic behavior.
    • Renewed sense of connection.
• Importance of psychedelic assisted by professional therapy:
  • Suggestibility and goal setting prior to experience.
  • Reinforcement and integration after experience.

 Value of non-ordinary states of consciousness:

• Ordinary consciousness is helpful, but not the only state possible.
  • Adaptive, optimized for survival.
• Non-ordinary states provide variation.
  • Expansion of repertoire of conscious states.
    • Explore other patterns of thought
    • Experiment along the lines of opening and contracting perspectives.
    • [Cultural enhancement, tweaking.]

Other Quote:

• Einstein: human’s sense of separateness is “a kind of optical delusion of consciousness”.