In Are Wireheads Happy? I discussed the difference between wanting something and liking something. More recently, Luke went deeper into some of the science in his post Not for the Sake of Pleasure Alone.

In the comments of the original post, cousin_it asked a good question: why implement a mind with two forms of motivation? What, exactly, are "wanting" and "liking" in mind design terms?

Tim Tyler and Furcas both gave interesting responses, but I think the problem has a clear answer in a reinforcement learning perspective (warning: formal research on the subject does not take this view and sticks to the "two different systems of different evolutionary design" theory). "Liking" is how positive reinforcement feels from the inside; "wanting" is how the motivation to do something feels from the inside. Things that are positively reinforced generally motivate you to do more of them, so liking and wanting often co-occur. With more knowledge of reinforcement, we can begin to explore why they might differ.

CONTEXT OF REINFORCEMENT

Reinforcement learning doesn't just connect single stimuli to responses. It connects stimuli in a context to responses. Munching popcorn at a movie might be pleasant; munching popcorn at a funeral will get you stern looks at best.

In fact, lots of people eat popcorn at a movie theater and almost nowhere else. Imagine them, walking into that movie theater and thinking "You know, I should have some popcorn now", maybe even having a strong desire for popcorn that overrides the diet they're on - and yet these same people could walk into, I don't know, a used car dealership and that urge would be completely gone.

These people have probably eaten popcorn at a movie theater before and liked it. Instead of generalizing to "eat popcorn", their brain learned the lesson "eat popcorn at movie theaters". Part of this no doubt has to do with the easy availability of popcorn there, but another part probably has to do with context-dependent reinforcement.

I like pizza. When I eat pizza, and get rewarded for eating pizza, it's usually after smelling the pizza first. The smell of pizza becomes a powerful stimulus for the behavior of eating pizza, and I want pizza much more after smelling it, even though how much I like pizza remains constant. I've never had pizza at breakfast, and in fact the context of breakfast is directly competing with my normal stimuli for eat...

n00bodyknows

n00bodyknows

n00bodyknows

n00bodyknows

n00bodyknows

n00bodyknows