For decades the working assumption was that dopamine was the pleasure molecule. More dopamine, more enjoyment.
It didn't survive the experiments, and what replaced it is more interesting.
The relocation
The awkward results came from several directions at once.
Amplify dopamine signalling and animals pursue harder — but don't show more hedonic reaction to the reward itself. Deplete accumbens dopamine and something stranger happens: animals still prefer the better reward, they just won't work for it. Put a barrier in front of it and they take the easy, worse option. Remove the barrier and the preference reappears intact.
That result, from Salamone, Correa and colleagues, is hard to explain if dopamine encodes pleasure. It's straightforward if dopamine is involved in effort, vigour, and behavioural activation — the willingness to overcome a cost to get something.
The field's account shifted accordingly: away from hedonia, toward instrumental behaviour, incentive motivation, and effort-based choice.
Why this matters outside the lab
If dopamine is about pleasure, the intervention is to reduce pleasure. That's the entire logic of the detox family, and it's why every version of it converges on deprivation.
If dopamine sits on the effort axis, that instruction is close to backwards. The problem isn't that your rewards are too enjoyable. It's that too many of them arrive with nothing in front of them.
Which reframes the day. A day of frictionless input — feeds, autoplay, delivery, infinite everything — isn't neutral just because none of it was excessive. And a day with hard things in it isn't costly just because it was tiring.
The asymmetry we encode
Myo treats effort as protective.
Every logged reward carries an effort cost, and effort determines how much of that reward's magnitude counts as unprotected. Unprotected magnitude is what depresses tonic level and feeds chronic load. Effort-gated reward largely doesn't.
The function saturates: the first bit of effort buys most of the protection, and more effort has diminishing returns. That shape is our modeling choice, not a measured constant, and it's the most load-bearing assumption in the product — so we label it as ours on the science page rather than dressing it up.
The practical consequence is the one that matters. Myo will never tell you to want less. It tells you to change what your rewards cost you to get.
What this looks like in practice
The instruction isn't "do hard things because hardship is good." It's narrower and easier.
Put a small cost in front of a frictionless reward. Not a big one. The saturating curve means a little friction buys most of the benefit — the point isn't suffering, it's that something had to happen first.
Stop scoring effortful rewards as indulgence. Exercise, cooking, playing something badly, seeing people — these show up in the model as protective. Detox challenges that strip them out alongside the feeds are removing the wrong half.
Count the frictionless share of your day. Not the total, the share. Two hours where everything arrived free is a different day from two hours where you had to do something first, even at identical duration.
The line
Dopamine looks less like the molecule of pleasure and more like the molecule of pursuit.
Which means the useful question was never "how much am I enjoying." It's "how much of what I got today did I have to do anything for" — and that number is trackable, unlike the one everyone argues about.