That’s an interesting anecdote about the satisficing thing! I don’t think it quite applies to animals because I don’t think animals are maximizing the sum of future rewards (see here). Anyway the system is already set up with separate channels throughout for good things happening vs bad things happening (there’s a thing I haven’t written about but believe where the striatum sends out a cost and benefit estimate separately rather than just adding them up, and also in the “assessor” zone here there are different channels because good vs bad things have different autonomic consequences, e.g. sympathetic vs parasympathetic). Also this says norepinephrine is slow-acting, which suggests that it doesn’t implement a learning rule tied to particular thoughts and actions and events.
But the article says it does affect learning rate, and arousal and whatnot. So maybe something like: NE and acetylcholine both signal “important things are happening now, let’s increase learning rate, tune the dial towards fast reactions at the expense of energy efficiency, etc. etc.”, but acetylcholine is fast and local (“important things are happening at this particular part of the visual field right now”) and NE is is slow and global (“I am in a generally important situation”)? Dunno, just speculating based on one abstract.
That’s an interesting anecdote about the satisficing thing! I don’t think it quite applies to animals because I don’t think animals are maximizing the sum of future rewards (see here). Anyway the system is already set up with separate channels throughout for good things happening vs bad things happening (there’s a thing I haven’t written about but believe where the striatum sends out a cost and benefit estimate separately rather than just adding them up, and also in the “assessor” zone here there are different channels because good vs bad things have different autonomic consequences, e.g. sympathetic vs parasympathetic). Also this says norepinephrine is slow-acting, which suggests that it doesn’t implement a learning rule tied to particular thoughts and actions and events.
But the article says it does affect learning rate, and arousal and whatnot. So maybe something like: NE and acetylcholine both signal “important things are happening now, let’s increase learning rate, tune the dial towards fast reactions at the expense of energy efficiency, etc. etc.”, but acetylcholine is fast and local (“important things are happening at this particular part of the visual field right now”) and NE is is slow and global (“I am in a generally important situation”)? Dunno, just speculating based on one abstract.