You know the shape of it even if you've never named it.
The first time was extraordinary. The tenth time was fine. The fiftieth time you did it anyway, felt almost nothing, and then felt slightly worse than before you started.
Most people read that as depletion — the tank runs low, the good chemical runs out. That reading is intuitive, popular, and wrong. The actual explanation is stranger and more useful, and it was worked out in 1974.
Two processes, not one
Richard Solomon and John Corbit proposed that every affectively charged experience sets off two processes rather than one.
The first is fast. It tracks the stimulus closely — it arrives when the stimulus arrives and fades when it goes. This is the hit.
The second is slow. It starts later, builds gradually, opposes the first in direction, and — critically — outlasts it. When the stimulus ends, the fast process stops but the slow one is still running. What's left is the comedown.
What you actually feel at any moment isn't the first process. It's the sum of the two.
The asymmetry that changes everything
If that were all, nothing would change over time. But repetition treats the two processes differently, and this is the whole insight.
The fast process stays roughly stable, or weakens slightly.
The slow opposing process gets stronger, starts sooner, and lasts longer.
Same stimulus. Same objective input. But the sum keeps shifting, because one term in the sum keeps growing. Less high. More comedown. Then eventually: barely any high, and a comedown that's the main event.
That's tolerance. Not an empty tank — a second process that learned.
Solomon and Corbit built the theory to explain drug tolerance and withdrawal, but they were explicit that it applies to ordinary acquired motivations too. Their favourite example ran the other direction: a first-time skydiver is terrified during the jump and stunned with relief afterward. A veteran is calm during the jump and exhilarated afterward. Same asymmetry, opposite starting sign. The fast process (terror) faded; the slow opposing process (relief, then exhilaration) strengthened until it became the reason to jump.
Why this reframes everything about "cutting back"
Under the depletion model, the intervention is obvious: stop consuming, let the tank refill. That's the entire logic of a dopamine detox, and it doesn't survive contact with the literature.
Under the opponent-process model, the intervention is different, because there's no tank. There's a learned second process, and learned things decay on their own schedule — slowly, unevenly, and in proportion to how thoroughly they were trained.
Which produces three consequences worth sitting with.
The comedown is not a side effect. It's the thing that's growing. When people track their habits, they log the reward. The opponent process is the part that accumulates, and almost nobody logs it, because it shows up hours later attached to nothing obvious.
Frequency trains the second process harder than intensity does. Repetition is what strengthens it. Forty small unremarkable hits train it more thoroughly than one large memorable one. This is why the habit that feels trivial is often the expensive one.
Stopping abruptly makes the imbalance loud. Remove the fast process and the slow one plays alone for a while. That's not proof you were addicted, and it's not proof the detox is working. It's arithmetic — you subtracted one term from a sum.
How Myo models this
We didn't reinterpret the theory. We implemented it.
Every logged reward creates a fast peak and feeds a slower opposing accumulator. That accumulator sensitizes — each prior peak increases how strongly the next one contributes — and it decays more slowly than the peak recovers. The line labelled "felt" in your chart is literally the first minus the second.
Which means when your felt line sits below your baseline hours after something good, that's not a bug or a mood. It's the second process, visible, with a number on it.
The specific coefficients are ours, not measured constants, and we say so — the constants are published alongside which parts are established theory and which are our parameterization.
The part worth keeping
There is no reservoir. There is a fast process you notice and a slow process you don't, and repetition makes the one you don't notice louder.
Once you can see the second process, "why doesn't this work anymore" stops being a mystery about willpower and becomes a question about what you've been training.