imagine, if you would, two room connected only by a slot in the wall. in each room sots a man, one american and one chinese. the chinese man passes slips of paper through the slot, and the american man looks at them and sends a corresponding response, as dictated by the instruction manual he has. in doing so, the chinese man may have a conversation of sorts.
the question however is this; does the american understand that a conversation is taking place? does he know what he does?
this thought experiment is meant to talk about ai systems imitating a polite conversation and is meant to prove that the machine isnt having a conversation but is rather running a ruse. i see no reason why we cant apply the logic to biological functions.
sure, your brain secretes dopamine but does it understand that that makes you happy?