A unification of Buddhist phenomenology, active inference, and physical reflexes; a practical theory of suffering, tension, and liberation; the core mechanism for medium-term memory and Bayesian updating; a clinically useful dimension of variation and dysfunction; a description of sensory type safety; a celebration of biological life.
Michael Edward Johnson, Symmetry Institute, July 12, 2023.
I. What is tanha?
By default, the brain tries to grasp and hold onto pleasant sensations and push away unpleasant ones. The Buddha called these ‘micro-motions’ of greed and aversion taṇhā, and the Buddhist consensus seems to be that it accounts for an amazingly large proportion (~90%) of suffering. Romeo Stevens suggests translating the original Pali term as “fused to,” “grasping,” or “clenching,” and that the mind is trying to make sensations feel stable, satisfactory, and controllable. Nick Cammarata suggests “fast grabby thing” that happens within ~100ms after a sensation enters awareness; Daniel Ingram suggests this ‘grab’ can occur as quickly as 25-50ms (personal discussion). Uchiyama Roshi describes tanha in terms of its cure, “opening the hand of thought”; Shinzen Young suggests “fixation”; other common translations of tanha are “desire,” “thirst,” “craving.” The vipassana doctrine is that tanha is something the mind instinctively does, and that meditation helps you see this process as it happens, which allows you to stop doing it. Shinzen estimates that his conscious experience is literally 10x better due to having a satisfying meditation practice.
Tanha is not yet a topic of study in affective neuroscience but I suggest it should be. Neuroscience is generally gated by soluble important mysteries: complex dynamics often arise from complex mechanisms, and complex mechanisms are difficult to untangle. The treasures in neuroscience happen when we find exceptions to this rule: complex dynamics that arise from elegantly simple core mechanisms. When we find one it generally leads to breakthroughs in both theory and intervention. Does “tanha” arise from a simple or complex mechanism? I believe Buddhist phenomenology is very careful about what it calls dependent origination — and this makes items that Buddhist scholarship considers to be ‘basic building-blocks of phenomenology’ particularly likely to have a simple, elegant implementations in the brain — and thus are exceptional mysteries to focus scientific attention on.
I don’t think tanha has 1000 contributing factors; I think it has one crisp, isolatable factor. And I think if we find this factor, it could herald a reorganization of systems neuroscience similar in magnitude to the past shifts of cybernetics, predictive coding, and active inference.
Core resources:
II. Tanha as unskillful active inference (TUAI)
The first clue is what tanha is trying to do for us. I’ll claim today that tanha is a side-effect of a normal, effective strategy our brains use extensively, active inference. Active inference suggests we impel ourselves to action by first creating some predicted sensation (“I have a sweet taste in my mouth” or “I am not standing near that dangerous-looking man”) and then holding it until we act in the world to make this prediction become true (at which point we can release the tension). Active inference argues we store our to-do list as predictions, which are equivalent to untrue sensory observations that we act to make true.
Formally, the “tanha as unskillful active inference” (TUAI) hypothesis is that this process commonly goes awry (i.e. is applied unskillfully) in three ways:
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