What Humans, Animals and Plants Tell Us About Consciousness | Michael Pollan

KEYPOINTS

• 01

  Consciousness is easy to recognize but hard to define

  Pollan starts from a few working definitions. One is simply subjective experience: a toaster has none, and he argues current AIs don't either. Another comes from philosopher Thomas Nagel's 1970s essay 'What Is It Like to Be a Bat?': if there is something it is like to be a creature, it is conscious. By that standard bats count, even though we can only roughly imagine navigating by sonar.

• 02

  Humans long assumed they had a monopoly on consciousness

  From Descartes onward, other animals were assumed not to be conscious. Pollan notes that the first mirror self-recognition test on chimpanzees was only around 1970, about 55 years ago, when scientists began accepting that other primates are conscious too. Building a universal standard around our own version of consciousness, he says, seems 'kind of crazy.'

• 03

  Consciousness may start with feelings in the brainstem, not thoughts in the cortex

  Pollan was persuaded by a line of work from Antonio Damasio in the 1990s and, more recently, South African psychiatrist and neuroscientist Mark Solms. Their view is that the brain exists to keep the body alive around homeostatic set points. The body reports on those set points through feelings like hunger, warmth, cold and itch, and consciousness arises from registering and acting on those feelings.

• 04

  Most vagus-nerve traffic runs from body to brain

  Pollan says about 80% of the information in the vagus nerve flows from the visceral organs up to the brain. Huberman, who teaches neuroanatomy, confirms the figure and puts the descending share at roughly 15–20%, though nobody knows exactly. They argue that we lack language for most bodily signals. Huberman suggests our current state may reflect body signals integrated over the previous ~10 hours.

• 05

  Plants show problem-solving that looks like intelligence

  Pollan distinguishes intelligence from consciousness but argues that plants handle novel problems, not just programmed reflexes. His examples are corn roots solving a maze and plants responding to the sound of feeding caterpillars. He doesn't think plants have the deliberate awareness that social life demands, but calls plant intelligence a fascinating field.

• 06

  Awareness may exist because social life can't be pre-programmed

  Most of what the brain does, like monitoring the body and adjusting to the environment, happens without awareness. The most persuasive explanation Pollan has heard, which he admits is an evolutionary 'just-so story,' is that human society is so complex that you can't automate every move. That requires theory of mind, imagination and deliberate choices.

• 07

  Consciousness without a self is possible

  Pollan points to the roughly 500 milliseconds after waking when you are reconstituting who and where you are. Huberman jokes it's 750 ms in a hotel room. That suggests consciousness doesn't have to be organized around a self, something Buddhists have long held. Pollan says psychedelics and experiences of awe also reduce the sense of ego, in a pro-social way.

• 08

  Pollan keeps 'filter' theories of consciousness open

  After surveying the theories, Pollan concludes we have no real idea how brain matter generates consciousness, if it does. Some argue the brain channels consciousness like a radio or TV receiver: you wouldn't look inside the set for the weather presenter. He doesn't endorse this view, or panpsychism, but no longer dismisses either.

• 09

  Building a conscious AI would test the feelings theory

  Some individuals and companies are trying to make AI conscious, not just intelligent, and those are different goals. If consciousness originates in feelings, it may depend on having a vulnerable body and perhaps mortality. Success or failure would both be informative.

• 10

  Caffeine is a drug most of us are dependent on, and mostly a beneficial one

  Roughly 90% of adults use caffeine daily, as coffee, tea or yerba mate. Pollan says it has many health benefits up to about seven or eight cups a day, after which problems begin, and some people get jittery on much less. He cites benefits for Parkinson's and blood pressure, plus polyphenols in coffee and tea that help the microbiome. These are his claims from researching the topic.