Path: utzoo!attcan!uunet!husc6!bloom-beacon!AI.AI.MIT.EDU!NICK From: NICK@AI.AI.MIT.EDU (Nick Papadakis) Newsgroups: comp.ai.digest Subject: (1) Free will & (2) Reinforcement Message-ID: <19880617035443.5.NICK@INTERLAKEN.LCS.MIT.EDU> Date: 17 Jun 88 03:54:00 GMT Sender: daemon@bloom-beacon.MIT.EDU Organization: The Internet Lines: 39 Approved: ailist@ai.ai.mit.edu Date: Tue, 14 Jun 88 09:56 EDT From: FLAHERTY%CTSTATEU.BITNET@MITVMA.MIT.EDU Subject: (1) Free will & (2) Reinforcement To: ailist-request@ai.ai.mit.edu X-Original-To: ailist-request@ai.ai.mit.edu, FLAHERTY Is it possible that the free will topic has run its course (again)? After all, the subject has been pondered for millenia by some pretty powerful minds with no conclusions, or even widely accepted working definitions, in sight. Perhaps the behavioral approach of ignoring (or at least "pushing") problems that seem to be intractable is not crazy in this instance. Anyway, it's getting *boring* folks. Now, re: reinforcement. It comes in (at least) two varieties -- positive and negative -- both of which are used to *increase* the probability of a response. Positive reinforcement is just old fashioned reward. Give your dog a treat for sitting up and it is more likely to do it again. Negative reinforcement consists in the removal of an aversive stimulus (state of affairs) which leads to increased response probability. If you take aspirin when you have a headache and the pain goes away, you are more likely to take aspirin next time you have a headache. Thus, negative reinforcement is the flip-side of positive reinforcement (and often difficult to distinguish from it). The effect of punishment is to *decrease* response probability. The term is usually used to describe a situation where an aversive stimulus is presented following the occurrence of an "undesirable" behavior. So, Susie gets a spanking because she stuck her finger in her little brother's eye (even though he probably did something to deserve *his* punishment -- there is no real justice). The hope is that Susie will "learn her lesson" and not do it again. Point is, punishment and negative reinforcement are *not* equivalent. See any introductory Psychology text for more (and probably better?) examples. --Tom