This would completely kill any potential reward (and replace it with the opposite, frustration) you're trying to train me with, please fix immediately.
I saw a gambler win the jackpot. He was really excited and started gathering up all the chips he'd won. Why he was so excited to win a bunch of plastic chips, I'll never know. What's so great about plastic chips? Why was his brain so excited when all he was doing was gathering plastic chips? ...
A half-second delay doesn't mean your brain can't learn to make the precursor feel good.
Similar to the rat knowing the sugar comes very shortly after the task.