Brain Karma

Examining habitual patterns and constructed reality through the lenses of neuroscience and Buddhism


This essay has been modified from the original version published at www.tricycle.com on August 7, 2014, which was written for a Buddhist audience.


It seems that everyone wants change: the latest tech gadget, a different job, a better relationship. Things “as they are” are somehow just not quite satisfying. Buddhists will recognize this situation as evidence of the first noble truth: dukkha — translated as suffering or “unsatisfactoriness” — is simply part of existence.

We often assume that happiness can be achieved by changing something in our external environment. But this assumption overlooks the fact that much of our dissatisfaction is perpetuated by our own minds. Our mental patterns can shape the way we respond emotionally to others, the way we perceive events, and whether we view the world and others as basically good or inherently flawed. They also affect simple, everyday aspects of our lives, like the way I tend to seek out chocolate and coffee in the middle of the afternoon. Mental and behavioral habits underlie the vast majority of our experience, and most operate without our awareness. Under the influence of such patterns, we can end up living our lives on autopilot.

From my perspective, these tendencies of mind are central to the Buddhist idea of karma, according to which each moment of consciousness is conditioned by previous moments, and the sum of our previous experience is the cause of each subsequent moment of experience. Our actions (including thoughts as well as observable behavior) leave a trace in our minds, making it more likely that similar actions will occur in the future. The Korean Zen teacher Daehaeng Kun Sunim summarized it well: “People are often careless about the thoughts they give rise to, assuming that once they forget about a thought, that thought is finished. This is not true. Once you give rise to a thought, it keeps functioning, and eventually its consequences return to you.”

This aspect of karma — at least as it relates to a single lifetime — is mirrored with surprising detail in the foundations of modern neuroscience. One of the most fundamental principles of neuroscience is known as Hebb’s law, also called cell assembly theory. In his 1949 book, The Organization of Behavior, the Canadian psychologist Donald Hebb laid out a principle that is often summarized by the phrase “Neurons that fire together, wire together.” In his seminal work, Hebb proposed that “any two cells or systems of cells that are repeatedly active at the same time will tend to become ‘associated,’ so that activity in one facilitates activity in the other.” This is the basic premise of neural plasticity — the ability of the brain to change through experience.

The mechanisms of neural plasticity are being revealed through an ever-increasing and nuanced body of research, showing how our brain networks are physically created and updated on a micro-level. For example, imagine two neurons connected such that activity in the first neuron makes the second more likely to fire. If we repeatedly stimulate the two neurons simultaneously, after a few hours, the same initial stimulation of the first neuron will lead to a larger electrical response in the second neuron — a change due in part to the release of more chemical neurotransmitters from the first cell and the presence of a greater number of receptors for that neurotransmitter on the second cell. These molecular changes serve to facilitate the relationship between the two neurons so that they are more strongly coupled. If repeated co-activation takes place over a longer time, the neurons will physically change their shape, sprouting new connections to solidify this effect even more.

Image by Greg Dunn (www.gregadunn.com)

The description above is a simple example of an interaction between two cells, but of course in the living brain, it is a process taking place at billions of connections every second. And each neuron is in conversation with thousands of others, creating an almost impossibly elaborate web of activity. Through the continual process of neural association, we slowly build up strong networks related to the things we experience frequently. These neural networks reflect our personal knowledge about a given object, person, or situation — in the form of sense perceptions, memories, emotions, thoughts, and behavioral responses.

In some cases these associations can be unhealthy. For example, I have a tendency to become anxious when I’m running late. This emotional response comes up regardless of the event in question, be it an important meeting (where the anxiety might be justified, but still not useful), or an informal social gathering (where the time of my arrival doesn’t much matter). This mental habit was formed early in life, in response to other members of my family becoming stressed or angry under time pressure. Slowly I formed an association between the situation of “being late” and stress, and my body and mind learned to respond accordingly. Of course, if asked, I realize my stress isn’t needed, nor is it doing any good. So why does this irrational pattern keep showing up?

In short, I continue to be anxious when running late because that’s what I’ve generally done in the past. As we move through our lives, brain circuits that are used more frequently become strengthened; that is, they are easier to activate than new or unused connections. Because less energy is needed for these familiar circuits to become active, patterns that are practiced become quite literally the “path of least resistance.” In many ways, the brain is an energy conservation machine: it uses 20 to 25 percent of the body’s cellular energy (while comprising only 2 percent of the body’s total weight), so there have been strong evolutionary pressures for the brain to be as efficient as possible. Just as water will flow through a well-worn riverbed instead of carving a new path into the bank, when the brain is faced with a choice between two actions, the one that is familiar, that has been repeated, will win out based on its energetic favorability.

To the extent that the idea of karma relates to the cycle of cause and effect, there are a lot parallels here. What’s essential is that every conscious phenomenon — thoughts and ideas, emotions and sensations, behavior in the world — is reflected at a cellular level. With each experience, millions of neurons come alive in a complicated network of activity. And to the extent that these specific patterns of activity are repeated, the neural connections are facilitated — the mental grooves deepen. As a result, engaging in any particular thought or behavior will make us more likely to engage in the same action in the future, as every act reinforces the neural connections that are associated with it.

Viewed from one side, this can be seen as energy conservation or simple biological cause and effect; from another side, this is a way that karma plays out in our daily lives. In a very literal sense, what we think, our brains become.


The karmic aspects of neural plasticity have important implications. Buddhism says that at the heart of suffering is ignorance and delusion — our inability to see the true nature of reality. Instead of seeing the interdependence and emptiness of all phenomena, we tend to view things as independent and stable, imbued with an essential nature. We reify the objects and people around us, making them discrete, separate, and assigning them inherent identities. Most of all, we take the same kind of concretized view of ourselves. This mistaken view of reality is the cause of dukkha, leading to an unending stream of desires and aversions aimed at satisfying and protecting our sense of self.

The brain’s capacity for neural plasticity facilitates this delusion, and it does so through the neuronal associations that contribute to concept formation. To examine one model of the process, consider this example of a basic visual stimulus (adapted from Thomas Lewis, Fari Amini, and Richard Lannon’s A General Theory of Love). Imagine a young girl just learning the alphabet. She encounters the capital letter A for the first time, and it happens to be written in a curly font. Upon seeing the A, a particular set of neurons in her visual system becomes activated. In the next alphabet book, the A has an apple at its base. In this case, another set of visual neurons will become active — many of the same neurons as for the first A (because of the similarities of the stimuli), and some different (because of the minor differences in font and appearance). In the third instance, the A is again slightly different, causing another group of neurons to activate, many of which overlap from the previous instances.

Each time the child sees another instance of the letter A, the neurons representing the common elements are repeatedly activated, and become more strongly connected following Hebb’s law. Here the common elements are two slanted lines connected in the middle with a horizontal line. According to this model, with repeated exposure the brain is naturally thus extracting the essential “A-ness” of the stimuli (based on commonalities). This is how the child develops a concept of the letter A. Later, that concept becomes elaborated, incorporating the sound and function of the letter in a word, and so on. Eventually, when the girl sees two slanted lines connected by a horizontal line, the strong neural A pattern will immediately activate, allowing her to recognize the letter and interpret its meaning effortlessly.

Conceptual processing is extraordinarily functional in terms of our ability to operate in the world and interact with others. Concepts are central to the way the brain learns and remembers. Without them, we’d be baffled by the simplest tasks, endlessly examining an unfamiliar item such as a spoon or a pen and wondering how it works, or what we should do with it.

But concepts also have a shadow side: by their very nature, they distort our perception. In the alphabet book example, the neuronal activations related to the differences between the letters are not reinforced, because they are not repeated — this is the flip side of Hebb’s law. Thus, because only the common elements of the A have been reinforced, when the woman sees an A, the neurons involved in processing those common elements will be activated much more strongly than the neurons representing the individuality of that particular letter. In effect, the woman actually does not perceive the unique elements of the stimulus as much as the common elements, because those neurons are not as strongly connected to the network. Perception becomes distorted. In neuroscience, the reinforced network is called an “attractor pattern” because it attracts cellular activity like a neuronal magnet. Energy will flow through the path of least resistance.

Interestingly, Buddhist thinkers have also examined how concept formation distorts our perception. For example, as the American scholar John Dunne has pointed out, the philosopher Dharmakirti (c. 7th century) claimed that repeatedly encountering a unique instance of an object will lead to a “false awareness” that emerges because we construct a “sameness” (a concept) for a class of objects. Due to our concepts, we don’t see the uniqueness of a given instance of that object. These ideas were put forth long before we knew anything about neurons; they emerged from a close examination of subjective experience. The striking parallels between this theory and our modern understanding of brain function highlight the potential for dialogue between Buddhism and cognitive science.

Concepts, therefore, are inherently reductive. Our perceptions are constantly being filtered through our previous experiences and resultant concepts. But the concept is not the reality. The true nature of the world has become obscured — phenomena become reified into the neuronal patterns we’ve developed over our lives.

We don’t see interdependence and impermanence because we crystallize everything into discrete preformed patterns that seem stable over time. We don’t see emptiness because we believe our concepts represent some true essential nature. It seems that a certain arrangement of lines is inherently an A, and will always be so. In the case of recognizing a letter, this may not be so problematic. However, the same process leads to the narrow labels we apply not only to objects but also to people.

Imagine a close loved one. You probably have a very clear idea of “who they are” — their personality and fundamental qualities that will persist over time. But in each encounter, our perceptions are being filtered through our well-worn concept of that familiar person. We believe the person we come home to in the evening is the same person we left that morning.

In the same way, we develop stereotypes about groups of people, lumping each new encounter into a preconceived “box” that has been set up and reinforced by societal and cultural influences. Even when meeting a stranger, we make many assumptions about their lives, motives, and tendencies by fitting them into our existing concepts.

The conceptual filters in our mind thus become a veil over reality, and we cease to truly perceive others — or ourselves — in the uniqueness of each moment.

Seen in this way, delusion — this misperception of the world — emerges spontaneously from the very way the brain wires itself. Ignorance is not due to some overactive brain area that needs to be quieted, or to some flaw or weakness in character. It is the natural result of a fundamental biological process. A necessary process that is beautiful in its elegance and utility, but also dangerous in its capacity for distortion.


Where does this leave us? Are we doomed to play out our lives at the mercy of our habitual neural patterns?

Both Buddhism and modern neuroscience say no. In fact, the neuroplastic capacities of the brain that contribute to our suffering become the same ones that hold the key to our liberation.

For centuries, the experiences of contemplative practitioners have shown that transformation is possible. More recently, neuroscience — in part because of its engagement with Buddhism — has discovered a previously unknown potential for brain plasticity throughout one’s lifespan. This is the good news: with repeated practice the brain can be changed, and to a surprising degree. Indeed, because neural plasticity is always operative, the brain is continuously being rewired based on our experiences. The key is to put some conscious intention into what those experiences are.

An increasing number of studies are investigating the impact of meditation on the brain, with promising results for our ability to change negative patterns of emotion and behavior. By practicing repeatedly, we can build awareness of our existing mental habits. With this awareness, there is space — allowing us to interrupt habitual response patterns and bring intention to our responses, choosing to form a different association. In time, we can begin to carve a new path into the riverbank.

This process is not an easy one: we are working against deep mental grooves that have been reinforced thousands, if not millions, of times. Competing with deeply reinforced patterns takes a lot of energy — meaning both effort and the cellular energy needed to support synaptic remodeling.

Although the work can at times be mentally and physically exhausting, we should take heart. As new pathways are laid down, the old ones begin to weaken from lack of use. This knowledge can give us encouragement: Change is indeed possible, but it’s also normal for the process to be difficult. We gain patience when we understand that it will take many repetitions of a new thought or behavior to carve out a different avenue for neural function. With dedication, we can slowly build healthy mental tendencies, for awareness and wisdom, for kindness and compassion.

As for transcending delusion, whether we can ultimately change the way concepts reify our experience is an open question for neuroscience, but traditional accounts do speak to the possibility of a direct experience of emptiness and interdependence. The brain correlates of these states are just beginning to be examined, and represent an exciting new frontier in the neuroscientific study of awareness.

Biologically speaking, we will likely never completely “undo” the physical manifestation of our mind’s conceptual structures. After all, we need our concepts to act meaningfully in the world. However, awareness can shape the way we relate to our concepts, allowing us to see them for what they are. With study and practice, we can move beyond our reductive thinking, lifting the veil to reveal the true nature of reality.

By leveraging the amazing capacity for change held within each of our brains, there is no question we can move steadily towards freedom from old patterns. And maybe that’s the change we’re all searching for — the change that brings real happiness.