October, 2021 - Neural Buddhist

Many meditation traditions involve developing our awareness of what is going on around us. Part of that work involves opening up to more fully experiencing the richness of sensation. But, even as our practice matures, and our awareness of the world deepens, even in that moment we are still surrounded by an invisible world, beyond our senses.

As I noted in an earlier post, our perceptions of the world seem direct, and unquestionable. In fact, though, our brains must do a lot of work to make an accurate guess about what the physical world is like. The gap between our perception and the physical world is something that we can easily demonstrate with visual illusions, where we find our perception is out of alignment with the physical world.

While the idea that our perception may skewed is easy to demonstrate, we may not appreciate that from the very first steps, our experience of the world is also very limited. At a fundamental level, our brains must do a considerable amount of work in order to gather information about the world, using our senses.

And, since gathering information is costly (in terms of developing and maintaining each sensory system), our senses are focused on finding the information that is most useful to us, not on representing the entirety of reality. So, while it may seem as if we have access to the entire world, what we can experience is really only a sliver of the reality that surrounds us in each moment.

What information is it that our brains focus on? Each of is probably familiar with our senses of sight, sound, smell, taste, and touch. To these, we should also add our vestibular sense (our sense of balance, and the ability to detect when our body starts moving or rotating), and proprioception (our sense of where our body is in space).

We often miss our vestibular and proprioceptive systems when we talk about sensation, probably because they often operate outside of our awareness. We may not even notice them until they are disrupted (think of getting dizzy after a carnival ride, or if you have ever experienced bouts of vertigo). Together, these senses represent the range of information that is available to us, through our direct experience, in each moment.

The challenge for each of our senses is to take some stimulus in the world (the chemicals that make up an odor, the waves of pressure that make up sound), and convert those stimuli into the language of the brain. Changes in the electrical potential across the membranes of the sensory receptors, which drive the release of chemical signals (neurotransmitters) that hand the signal off to the next step along the path to the brain. Research on the neuroscience of sensation has made great advances in our understanding of the intricacies and activity of our major sensory systems. Today we can describe in very fine detail the major steps that go into each of our sensory experiences.

For example, this fall, the 2021 Nobel Prize in Medicine recognized the work of Dr. Ardem Patapoutian and Dr. David Julius on the neuroscience of sensation. Specifically, the prize was awarded for Dr. Patapoutian’s work on proteins that are critical for our sense of touch, and Dr. Julius’ work on the proteins that allow us to detect heat, cold, and pain (and, which are targeted by the chemicals in chili peppers, making them spicy).

The work by Drs. Julius and Patapoutian represent important advances in our understanding of the very first steps of sensation: taking some information from the world (light, vibrations, sound, flavor) and converting that information into the language of the brain. Research in this area has greatly advanced our understanding of how our brains are able to “touch” the world around us, by recoding physical stimuli in neural signals. The proteins that Drs. Julius and Patapoutian have characterized are a key step in this process. Having a protein that can start the process of turning heat into a change in the electrical potential of a neuron is the first step in building a window into the world around us. And without these proteins, we would be deeply anesthetized, unable to feel physical contact with much of the world.

And, research across our sensory systems has also demonstrated the limits of our sensation. We can only directly experience stimuli for which we have receptors. And even then, only for stimuli that fall in their working range.

So, as we look closely at our sensory systems, we find that our direct experience of the world is limited in two major ways: 1) in the range of information we can detect, and 2) in the kinds of information that we can detect.

All of the light we can see is just a small slice of the electromagnetic spectrum.

For the first point, consider vision. Most humans with normal vision can see a rich range of colors. (And, even humans with color vision deficiencies (often referred to as color-blindness) can distinguish a wide range of colors).

Color is our direct, personal experience of the wavelengths of light around us. What we typically refer to as light is technically visible light. For most humans, visible light is made up of electromagnetic radiation (photons) which have wavelengths that fall in a range from about 400 nm (violet) to just over 700 nm (red), stretching from violet to red. Any color that we can perceive is a representation of the wavelengths (or mixtures of wavelengths) of light that are entering our eyes at the moment.

But, what lies outside of this range, and outside of our vision? Photons with shorter wavelengths we call ultraviolet (UV) light and gamma rays, while photons with longer wavelengths make up infrared light, microwaves and radio waves. Think about that for a moment. Radio waves, gamma rays, and the calmest color of green we have ever experienced. All are in reality photons, and the only important difference between them is their wavelength.

At this moment, some of those other photons, for instance UV and infrared photos, are all around you. Some are passing into your own eyes. And yet, most likely, you can’t see those photons in the UV spectrum, or infrared light. But, why not? Is it impossible to do so?

Of course not: we can easily “see” UV and infrared light by using special tools (think of infrared (IR) cameras, which allow us to image heat, or see in the dark, when there is little visible light).

And, other animals have visual systems that detect UV or infrared light. Bees, for instance, have a visual system that is sensitive to a range of wavelengths that is similar to humans, but shifted to shorter wavelengths, including the ultraviolet range. Many flowers have evolved to have striking UV patterns which serve as cues for pollinating insects like bees, so the experience of a flower is very different for bees and humans, even from the very first step. So, beauty truly is in the eye of the beholder (or at least starts there).

Flowers under visible light and UV filters. Credit: How Plants Work

Outside of vision, this point holds as a general truth: that what we can perceive is only a fraction of what exists around us at any moment. Consider sounds that are very low, or very high in pitch (beyond our hearing), textures too fine for our fingers to catch, and odors too faint for us to detect. All of these exist in the world, right here and now, just beyond what we are experiencing.

On the second point I raised above, we are not only limited in the range of our experience, but also in the very kinds of sensations we can experience. There are qualities of the physical world that we can demonstrate exist, but which we cannot feel directly. Other animals can, though. For instance, numerous species have developed receptors that allow them to detect types of stimuli that humans do not experience directly, such as magnetic fields, the polarization of light, or electric fields (usually by animals such as fish, living in the water).

In each case, these species of animals have developed proteins that can detect stimuli in the world, and sensory systems that represent that information in a useful way. This allows these animals to directly experience physical stimuli in the environment to which we ourselves are blind. Birds use magnetic fields for navigation, similar to our use of a compass. Some fish have a passive electrical sense, that allows them to feel electrical fields in the water, while others actively generate electrical fields that allow them to feel objects in the water. While we sometimes think of these electric fields as weapons (in the case of electric eels), more often the electric sense is used to feel what is in the water in conditions where vision is ineffective.

So when we look closely at what we can bring into our awareness of the world, we find that humility is always warranted. Right now, in this moment, there is more to the world than what we can experience directly. That invisible world lies beyond our senses, beyond what we can ever experience directly. To reflect deeply on this is important, lest we become overconfident. We cannot hold the entirety of this moment of the world in our perception.

But along with humility, gratitude is also warranted. While our experience is only a sliver of reality, life is so bountiful that even a drop has depths that we cannot exhaust.

In our meditation practice, we hope to better see clearly the true nature of reality. What is it that we see, as we turn our attention to look at our own self? One fundamental insight is that our sense of self, the solidity of “I”, is a kind of illusion.

A tree near our home is showing its age, its branches losing leaves and the center slipping into decay. From a single seed, it grew to towering heights, reaching for the sky as it stood tall over us for many years. And now, it has reached the end of its life. We naturally think of this tree as one living being, the same thing that has been with us since we moved into our home. But, what really remains of that tree, even now, that was there at the beginning?

I have often asked this same question of myself: what really remains, or persists, of my self across time? Day-to-day, and moment-to-moment, it is easy for us to feel that the thread of our identity is unbroken. Of course, I tell myself, I am the same person now (the same, unique individual), that I was an hour ago, or last week, last year. But, why am I right to feel so confident about this point? Consider longer windows of time: as I look back at photo of myself as a child, what really, deeply connects the person who smiled so long ago for the camera, to the person holding that photo today?

As living beings ourselves, each of us is composed of a rich tapestry of cells, from our skin, to our muscles, and the cells that organize and oversee the construction of our very bones. Our brains are no exception, and trillions of cells (called neurons) make up that intricate web in our heads. Each of our thoughts, feelings, memories depends on the activity and integrity of our neurons. The cells that make up us work together, forming a community of sorts. But, they are separate units, and fundamentally replaceable. We could swap out pretty much any cell in our body for a physically identical copy, and we have no reason to think that our body, or our experience, would be impacted.

Where then, is the “I” among all of the trillions of separate cells that form the community of my body? How is it that I persist from moment-to-moment, and day-to-day? Personally, I have found it useful, when thinking closely about our bodies and our selves, to see that what is critical is the pattern of activity that those cells, especially those in the brain, maintain over time.

Neon whirlpool — Photo credit: Creativity103

When I was younger, and beginning to explore Zen, one metaphor that shaped how I understood my self came from a talk given by Charlotte Joko Beck (collected in her book Nothing Special: Living Zen).

We are rather like whirlpools in the river of life… Though for short periods it seems to be distinguishable as a separate event, the water in the whirlpools is just the river itself. The stability of a whirlpool is only temporary. The energy of the river forms living things – a human being, a cat or dog, trees and plants – then what held the whirlpool in place is itself altered, and the water passes on, perhaps to be caught again and turned for a moment into another whirlpool.
Charlotte Joko Beck, “Nothing Special: Living Zen“

The image of a whirlpool, something that we recognize is, at its very core, a transient process – ephemeral – was very useful. With living things, it can be easy to treat them as solid and firm, like the tree near my home. But, we ourselves are no less a dynamic process than is a whirlpool. Across our life, from conception, to birth, aging and death, our physical bodies play out as a dynamic structure of matter and energy. Even in adulthood, after our form has stabilized (for the most part!), we are constantly taking in physical matter (through food, drink, and even the very air we breath).

Beck used the metaphor of the whirlpool to explore the ways that we become defensive, protective, if we identify ourselves only on the basis of our temporary form.

We’d rather not think of our lives in this way, however. We don’t want to see ourselves as simply a temporary formation, a whirlpool in the river of life… We want to see ourselves as permanent and stable. Our whole energy goes into trying to protect our supposed separateness.
Charlotte Joko Beck, “Nothing Special: Living Zen”

In Beck’s talk, she considers how as becoming protective of our transient form, our whirlpool, can lead us to try to hold on to what comes through our whirlpool. Or, to try to erect barriers, turning ourselves into “stagnant pools.” She asks us to consider shifting our view, from identifying solely with our self as a separate being, and to turn our attention back to the ways in which we are deeply connected to everything (the river).

For me, the metaphor of the whirlpool has also been useful in other ways, to help me think about what we really are, in this world. We often treat living things (my self, my family, our pets, the tree outside of our home) as real things that have a stable existence. This attitude has value for us – it is fundamentally useful to us – and for our ability to function in the world. As social beings, the ability to take into account the history of another being in our interactions is key, helping us to know who is likely to be a source of support, or who might put their own desires above the needs of others.

But while it can be useful to think of living things as stable, and enduring, this firmness turns out to be an illusion. Much as whirlpools begin with gentle rotation, mature, and then fade, living things typically go through a rapid development of their physical form, reach some stability in adulthood, and experience a decline towards the ends of their life. Even if we look the same from one day to the next, we are fundamentally dynamic processes, changing in every moment.

Across this arc, what persists that could be a self? Physically, there is little to nothing left in terms of my actual body today that was with me when I was an infant. In many parts of our body, our cells age, die and are replaced with new cells. Even in those cells that persist (in our brains, for instance, many of our neurons will survive for most of our lives), proteins and other molecules are constantly being replaced. Through respiration, we let go of a part of ourselves, the carbon that has been bound to the oxygen we brought in: we shed something of ourselves with every breath.

In the same way that a whirlpool is a stable pattern, living beings are a stable structure, but not static: physical matter pours into them, and through them, with every breath, meal, and drink.

But, while living beings, ourselves included, are transient patterns of matter, could the stability of our identity be in the mental, rather than the physical, domain? If we look closely, we can see that this is probably not the case. Each thought, memory, emotion we have or experience depends on the activity of the brain. So, anything that appears to be stable in our mental experience is weaved from the activity of a body that is in constant flux.

To look at the relationship between our brains and our conscious experience, another piece that I have personally found meaningful is the short story, “Exhalation,” by Ted Chaing. In the story, Chaing’s unnamed narrator describes a strange world, where all of the inhabitants appear to be mechanical creatures, powered by compressed air. The people living in this world must refill their metal “lungs” regularly from a source of compressed air, some vast underground reservoir. If they fail to do so in time, and their lungs run out of air, they will go limp. Replacing their depleted lung with a full one will bring them back to life, but with all of their memories erased. Indeed, it is not clear if the dead who are revived in this way are able to function at all.

The narrator of the story describes his attempts to understand the workings of their own mechanical brains, and in that way understand the source of their memories. He doe this by examining his own brain in great detail. I won’t go into specifics (as I would not want to ruin the story for you, and I would highly recommend it!), but part of the key insight is that pressurized air is used to power a set of tiny switches (essentially air-based transistors), to accomplish the same kinds of computations that our own brains use.

This insight, seeing clearly the relationship of the air to the narrator’s own conscious experience, produced a profound shift in understanding of their own identity.

… I saw that air does not, as we had always assumed, simply provide power to the engine that realizes our thoughts. Air is in fact the very medium of our thoughts. All that we are is a pattern of air flow. My memories were inscribed, not as grooves on foil or even the position of switches, but as persistent currents of argon.
Ted Chiang, “Exhalation”

With the metaphor of the whirlpool that I described above, often I have thought of our whole bodies as whirlpools: intricate patterns of matter, spinning across the arc of our lives. But, when we focus on our mental experience, our thoughts, feelings, memories, I think that this view can be refined, and I have found the image that Chaing has crafted to be very helpful here.

If we (our conscious experience, our persistence as a person over time) are a whirlpool, then our bodies (including our brains), are the rocks and structure of the river bed, which steers the water of the river into the shape of a whirlpool. Just in the same way as the mechanical brains of the beings in Chaing’s story, where the air flowing from the lungs was harnessed as it flowed through them. Their thoughts were made from the air, but were also separate from it, in the same way that a whirlpool is made from water, but is a different kind of thing.

While we need to breathe to live, just as the narrator in Chaing’s story, the nature of our respective needs are different. For us, breath is critical to bring in fresh oxygen (so that we can make use of the energy that is stored in our cells) and to remove the waste products of respiration (such as carbon dioxide). The breath was the very energy that animated Chaing’s beings: all of their lives depended on the reservoir of pressurized air that powered their minds.

For humans, and most of the rest of the life on our planet, our energy doesn’t come from pressurized air, but instead from sunlight. The force that propels our limbs, drives our blood, and gives speed to our thoughts comes from our sun. That energy could have fallen simply onto the earth itself, warming the planet a bit more. But, some of it was captured by plants, and stored away until it could be released, slowly, and (in a sense) intentionally. In the same way that a windmill harnesses the force of the wind that would otherwise pass by, or a solar panel harnesses light, plants store the energy of sunlight in chemical form.

Every thing that we have done, each word we have spoken, each home we have built, each moment of delight we have felt, has been powered by the sun.

So, instead of air, “the very medium of our thoughts” is, fundamentally, sunlight. The power for our thoughts comes from the energy that has been stored from the sun. That energy powers the neurons of the brain. The activity of those neurons (in the electrical and chemical signals that neurons use to process information and communicate) leads to our conscious experience, the whirlpool that is our self.

Chaing ends the story ruminating on the deep connection of life to entropy: his narrator’s life plays out in the movement of the universe from order (pressurized air) to disorder (equilibrium, where there is no difference in pressure).

The universe began as an enormous breath being held. Who knows why, but whatever the reason, I am glad that it did, because I owe my existence to that fact. All my desires and ruminations are no more and less than eddy currents generated by the gradual exhalation of our universe. And until this great exhalation is finished, my thoughts live on.
Ted Chiang, “Exhalation“

But what about us? In an important sense, all of our motion (each movement, thought, memory) depends on a “breath” that was taken when our universe began in the Big Bang. Our existence depends on the creation of the stars, including our own sun. While in principle there are other sources of energy that we can harness, every food that we consume represents energy that was captured and stored from sunlight that fell on our planet.

Most of that light, a vast amount of it, races past our planet, out into the vastness of space. Perhaps some of that light will be detected someday, by some other civilization, and spur some impact there. But, the majority of it will never have a strong effect on the universe at large, or on sentient beings at all.

That tiny, tiny fraction that falls on Earth though? Living beings harness only a fraction of that light (our plants absorb a tiny slice of light, a small range of wavelengths), and that sliver of the bounty of our sun is enough to power the vast web diversity of life on our planet. Each and every thing that we do depends on using that energy. It is true that someday, our sun and the other stars will exhaust their reserves, and the universe will reach some new state (possibly to settle into its own quiet non-existence, perhaps to head to some new rebirth).

But, just as each whirlpool will merge back into the river, the moment that our universe settles back into stillness will come when it will come. Well beyond the limit of our own lives, and very likely beyond that of our species. For us, the present is more properly our concern. If we can preserve our own planet, we can continue to nurture the miracle of our collective whirlpool, the communities of sentient beings that spring into existence on the Earth, and we can continue taking delight in existence and in this great exhalation of the universe.

Recent Posts

Categories