Archive for the ‘conditioning’ Category

030819 – Emotion and incentive

Tuesday, August 19th, 2003

030819 – Emotion and incentive

I really don’t like Joseph LeDoux’s (2002) use of the words emotion and incentive.  He uses emotion to mean just about anything that can affect synaptic plasticity, that is, he defines the term backwards.  That doesn’t work because we don’t know what can affect synaptic plasticity, but we do have a good idea of what we think emotion means.

Similarly, incentive.  To my mind an incentive is a conditional promise of reward in the future.  It takes the form, “if you do this you’ll get that.”  The term is a bit confusing in ordinary speech.  Management announces an incentive program whereby workers who overfill their quotas will receive a significant bonus.  The announcement serves as the incentive for employees to work harder.
Hans-Lukas Teuber (Chair of the M.I.T. Psychology Department while I was getting my Ph.D there) liked to tell the  story of the monkey and the “consolation prize.”  The monkey works to get a piece of banana, but when the monkey gets the piece of banana, he doesn’t eat it, he just sticks it in his mouth and holds it in his cheek.  When the monkey makes a mistake and doesn’t get a piece of banana, he eats some of the banana he was holding in his cheek.  So the monkey “rewards” himself for making a mistake.  Teuber called it a “consolation prize.”

So the (implicit) promise of “a piece of banana if you do this correctly” is the incentive (I actually would have said motivation here—LeDoux can’t because he uses motivation to mean something else).  What’s the banana then?  A reward?  Maybe, but in the context of the situation, the banana is the confirmation that the incentive was correctly understood, and that, in itself is (arguably) rewarding.

It should be rewarding, in any case, by the following argument.  It is clearly adaptive for an organism to be able to reliably predict the way the future will unfold, particularly with respect to possible events that have (can have, may have) some kind of significance to the organism.  It is even more important for an organism to be able to reliably predict the effects of a possible action

“I’ll bet that if I figure out what to do here, I’ll get a piece of banana.  Hmmm.  This looks right.  I’ll do it.  Banana!  Yes!  I was right!”

Or

“I’ll bet that if I figure out what to do here, I’ll get a piece of banana.  Hmmm.  This looks right.  I’ll do it.  No banana?  Bummer!  I didn’t get it right.  I’m gonna eat a piece of banana.”

So, back to the question: what is the banana?  In evolutionary terms, at one level, the banana is nourishment and valuable as such; in this context, however, the banana is real-world confirmation of correct understanding of (at least one aspect) of the real world.

But notice the subtlety here.  Setting aside our knowledge that correlation is not causality (which we seem to do a lot), the banana confirms the existence of a pattern: In the context of this recognizable situation it is to be expected that a problem will be presented and if I correctly figure out what the situation requires and do it, I will get some banana and if I don’t figure out what the situation requires, I won’t get any banana.

If no banana is forthcoming, what is the correct conclusion in this situation?  There are several: 1) I got it wrong (everything else is unchanged); 2) I got it right, but there are no more bananas at the moment (everything else is unchanged); 3) The pattern is incorrect: there are no bananas to be had here.  This is clearly not an exhaustive list of all the alternatives, but it does indicate that the conclusion to be drawn in the situation is by no means obvious.  This is borne out by the well-known fact that behavior patterns established by a random reinforcement pattern are more resistant to extinguishment than patterns established by a 100 percent reliable reinforcement pattern.

Again let’s look from an evolutionary standpoint: Which is more important?  Obtaining a piece of banana or knowing how to obtain a piece of banana?  If I give a man a fish, I have fed him for a day; if I teach a man to fish, I have fed him for life.

An important question for an organism is: Where is food?  The obvious next question is: How do I get there? Once these questions are answered, the next question is: Once I get there, how do I get it?  I have a feeling that in the brain these questions, or rather the answers to these questions, are intimately related.  Ultimately, an organism needs a procedural answer: What steps need to be taken in order to arrive at the desired goal?  The organism needs a sequential plan.  It makes me wonder if the parietal lobe in addition to its involvement with the representation of physical space also is involved with the representation of conceptual space.

Maybe not.  Physical space has obvious nearness relationships that conceptual space does not necessarily have.  On the other hand, George Lakoff’s arguments about the way in which meanings are derived from physical relationships may suggest that parietal lobe involvement (or, more precisely, involvement of whenever part of the brain is responsible for keeping track of the physical organization of the universe with respect to the organism) in the organization of concepts is in fact plausible.

Correlation is not causality, but from an evolutionary standpoint an organism cannot in general afford to do the necessary research to establish reliable causality.  Interestingly, human beings have acquired the ability to reason systematically and have managed in some cases to determine causality.  What is more significant, and many have remarked upon this, is that humans can transmit patterns verbally to other humans.  Not only that, patterns thus transmitted can be used by the receiver almost as if they had been directly precedent or intuited or whatever the appropriate word is to describe the way we acquire patterns.  I say “almost” because I think there must be some difference between patterns established by word-of-mouth and patterns established by other means.

I don’t think, however, that the difference is as simple as the difference between declarative and non declarative memory.  And by the way am not real happy with the use of the word declarative.  And I guess part of the reason for that is that I think some if not much of things that enter “declaratively” ends up stored “non declaratively”.  Which, I suppose, is simply to say that we don’t always consciously examine the implications of things that we hear, but those implications may end up being stored.  Perhaps this is just a matter of “stimulus generalization”, but whatever it is, it feels like a hard and fast distinction between declarative and non declarative memory is ultimately misguided.  And, in fact, studies of “priming” and in individuals whose declarative memory system is damaged in some way seem to me to imply that non declarative priming (whatever that means) also occurs in those whose declarative memory system is intact.

I suppose the argument is simply that there are two kinds of memory, but things start to feel a little too glib when people start to discuss the pathways by which information enters one memory system or the other as if in the intact organism there is no (and can be no) “crosstalk” between the two.  Maybe it’s just that in the course of reviewing the literature of the past thirty years I have concluded that where there are dichotomies it is important, even essential, not to accept them literally, for fear of missing overlooked clues to the functioning of the system.