Perceiving Reality through Bayesian Inference and Buddhist Philosophy

Gannon Hall
5 min readMay 23, 2023

The human mind, a complex maze of thoughts, experiences, and sensations, shapes our perception of reality. It is both an algorithm and a storyteller, continually predicting, observing, and updating a narrative of the world. The principles of Bayesian inference, a statistical method built on the logic of updating beliefs with new evidence, intersect with the wisdom of Buddhist philosophy in four ways: the perception of reality as a mental construct, the recognition of impermanence and change, the practice of mindfulness and perception, and the root of suffering in attachment.

Reality as a Mental Construct: A Bayesian and Buddhist Perspective

Bayesian inference, translated into cognitive function in the Bayesian Brain Hypothesis, considers perception through the lens of Bayesian statistics. Our brain employs “prior probabilities,” beliefs formed from past experiences and current understanding. This intricate mental model of the world is continually refined by new sensory input — the raw data of experience — producing “posterior probabilities” or updated beliefs. Here, our perception of reality emerges not as a static, objective entity but as an evolving and observable construct of the mind.

This perspective resonates well with the Buddhist concept of Maya, or illusion. In Buddhist teachings, the reality perceived through our senses is not the ultimate reality but a layer of illusion. Our habitual thought patterns, desires, and fears color our perception, casting a veil of subjectivity over the truth. Hence, both Bayesian inference and Buddhism converge on the view that our perceived reality is largely a mental construct shaped by our beliefs and experiences.

Impermanence and Change: A Constant in Bayesian Updates and Buddhist Wisdom

At the heart of the Bayesian Brain Hypothesis is the essence of change. The brain’s understanding of reality is never static; it is continually updated, driven by the constant flow of sensory data. Bayesian inference is, fundamentally, a dance with change and adaptation.

This perception of change mirrors the fundamental Buddhist concept of anicca, or impermanence. Buddhism teaches that all conditioned phenomena — everything influenced by other factors — are in constant flux. Just as the Bayesian brain must adapt to new information, Buddhists are encouraged to recognize and accept the inevitability of change.

Mindfulness and Perception: From Psychedelic Insights to Buddhist Practice

In the realm of cognitive neuroscience, the potential of psychedelics to alter our perception has long been a topic of speculation and, more recently, legitimate scientific research. It is proposed that psychedelics might “flatten” the weight of prior probabilities in the Bayesian brain, allowing new sensory data to play a larger role in shaping perceived reality. This shift could open the doors to novel or more “positive” perceptions of reality, breaking the chains of past patterns and biases.

This potential effect of psychedelics parallels the Buddhist practice of mindfulness. Mindfulness involves observing the present moment non-judgmentally, reducing the impact of habitual thought patterns. It fosters a transparent, “unfiltered” perception, akin to allowing new sensory data to have an increased impact on our mental construct of reality.

Attachment and Suffering: Clinging to Priors and Desires

An intriguing parallel emerges between the notions of attachment in Bayesian inference and Buddhism. In the Bayesian context, one might argue that our brains’ reliance on prior probabilities reflects a form of “mental attachment.” A strong prior can bias our perception and lead to potential mismatches between our expectations and the incoming sensory evidence, causing a form of cognitive dissonance that can result in distress or discomfort.

This cognitive process mirrors the Buddhist understanding of suffering or dukkha, often traced back to attachment or upadana. According to Buddhist teachings, our attachment to desires, views, and perceptions entangles us in the cycle of suffering. The habitual clinging to particular views of reality, similar to the strong priors in Bayesian inference, can create a gap between our expected and actual experiences, leading to various forms of distress or dissatisfaction.

The practice of mindfulness, wisdom, and ethical conduct outlined in the Noble Eightfold Path offers a way out of this cycle. By cultivating awareness of the present moment and reducing the influence of our habitual thought patterns, we can lessen the gap between expected and actual experiences, thereby reducing suffering.

As we better understand the functioning of the mind through the lens of Bayesian inference and incorporate the practice of contemplative philosophies into our lives, we equip ourselves with tools to navigate the complexities of subjective experience, elucidate new insights and alleviate the suffering caused by maladaptive perception.

Psychedelics, Maladaptive Perception, and the Path to Liberation

Emerging research at the intersection of cognitive science, Buddhist philosophy, and clinical psychology deepens our understanding of maladaptive perception — the skewed interpretation of reality central to the modern trifecta of psychic suffering: depression, anxiety, and addiction.

Depression often involves the persistent view of the world and oneself through a negative lens. It’s like the Bayesian brain getting locked into a cycle of strong negative priors, continually reinterpreting new data in pessimistic ways. Similarly, addiction can be seen as a form of clinging to strong priors linked to the perceived pleasure or relief associated with a substance or behavior. Despite adverse, sometimes deadly consequences, the Bayesian brain struggles to update these harmful priors. Meanwhile, anxiety is like an overactive prediction system, with the brain consistently overestimating threats, causing chronic worry and fear.

In this context, psychedelics are a potent tool to disrupt entrenched patterns of maladaptive perception. By deweighting the hold of harmful priors, psychedelics help to rewrite the narrative, introducing novel pathways of thought and breaking the debilitating cycles inherent in these conditions.

Psychedelics prime the brain for new pathways to form by increasing its “neuroplasticity.” Yet, in line with both Bayesian and contemplative theory, the “jolt” provided by psychedelics should not be mistaken as a shortcut or one-time cure. The therapeutic potential of these substances rests on the degree to which the cognitive insights are integrated into everyday life. This ongoing work echoes the practice of mindfulness and related contemplative practices. Comparable to maintaining physical health through regular exercise, nurturing mental health requires sustained practice. These practices serve as the “cardio” for the mind, reinforcing the changes initiated by the psychedelic experience and fostering a continued evolution of perception towards a healthier, more adaptive engagement with reality.

The intersection of Bayesian inference, Buddhist philosophy, and modern therapeutic practices offers invaluable insights into our understanding of maladaptive perception and its role in mental health disorders. Moreover, it provides a framework for exploring the therapeutic application of psychedelics. By continually updating our models of reality — through Bayesian inference, Buddhist practice, or therapeutic interventions — we open up a pathway toward healing, growth, and liberation from suffering.