Instrumental Learning What is Reinforcement o What makes something reinforcing Increases a behavior Positive and negative reinforcement o How can we explain differences in what we find reinforcing Something that reinforces one may not reinforce another There are also differences within one individual at a different Individual differences about humans and animals Across and within species time Depending on factors such as physiological state Traditional Definitions o Thorndike A stimulus that produces a satisfying state of affairs A stimulus that strengthens instrumental behavior But why does it strengthen instrumental behavior Historic Drive Reduction Theory Clark Hull A thing that is given or a thing that you get All organisms have basic drives Species survival kinds of things E g biological motivation for food water shelter for individual survival The particulars depend on species Reproduction for species survival Idea Primary reinforcers satisfy those drives Problem cannot explain many strong reinforcers Your drive then reduces when you obtain these things Primary reinforcers Don t have to be learned Music art novelty Secondary reinforcers that do not lead to primary reinforcers o Contemporary View Theories focused on how why reinforcement changes the Redefine reinforcement organization of an animal s activities Not a special stimulus Reinforcement is a behavior E x Food is not the reinforcer the act of eating is reinforcing o Consummatory Response Theory Species typical responses are reinforcing For a given species what are their specific behaviors Modal action pattern behaviors can be reinforcing Chewing licking swallowing of food These behaviors are special and different from the instrumental behaviors they reinforce e g lever pressing Problem like drive theory does not explain many reinforcement effects o Premack Principle 1959 Higher probability behaviors can reinforce lower probability Something you would prefer to do if you had no constraints can behaviors reinforce something you would not prefer to do if given the choice between the 2 The way you choose to organize your behavior out of all the options that you have Pinball Candy Experiment Candy preference kids play more pinball to get Pinball preference kids eat more candy to play candy pinball Alternatives to premack o Response Deprivation Hypothesis Aka disequilibrium model Restricting access to a response makes it more reinforcing Even a low probability behavior can be reinforcing if it is limited Experiment Subject rats Responses 3 phases Running on a wheel Licking a sprout for sucrose solution Free access establish baseline Licking contingent on running 30 spins for 10 licks Running contingent on licking 60 licks for 5 spins o Applied use Classroom management Psychiatric treatment o Response Allocation Goes beyond Premack or Response Depp Hypothesis the organism has an optimal distribution of Behavior changes to get back to that bliss point or as close activities Behavioral Bliss Point Instrumental contingencies force the individual out of that optimal state as possible Example Doesn t like to spend much time studying Student likes to watch TV Bliss Point 60 min TV for every 15 min studying We want to increase studying What does Response Allocation theory predict Experiment Contingency 1 min study 1 min TV Behavioral regulatory mechanisms minimize deviation from bliss point o Summary Premack Response Deprivation Response Allocation theories Redefine reinforcement as a behavioral response not a special kind of stimulus Instrumental conditioning is creating a new distribution of behaviors Instrumental responses and reinforcer responses are defined by the contingency that the experimenter or trainer assigns Shortcoming no explanation for how the trade offs are determined Extinction o How do we eliminate conditioned responses Stop presenting the US Stop reinforcing a response o What happens when we stop presenting the US or stop reinforcing a response Extinction o How does the original training effect the process o Extinction Repeated presentation of the CS with no US or No reinforcement for a previously reinforced behavioral response o Contrast with forgetting Forgetting results from the passage of time Extinction active training process Expose to CS alone or operant responses alone Doesn t occur simply to time passing o Features of Extinction Creates frustration Extinction bursts Expectation of US reinforcer not met Frustration is actually a good technical term Bursts of responding that occur early in extinction training May happen multiple times amount varies b w individual Change up how they press the bar put both paws on bar Ex in humans pressing elevator button more or harder Increased response variability biting the bar unlocking a door Reduce CR or operant responding o How do we know that extinction doesn t erase the original learning The original learning can still be observed after extinction The old learning can be brought back Spontaneous recovery Different from in habituation Take a break from training after extinction need to achieve thorough extinction first No reinforcement or US increase in responding again Bring them back into situation and there will be an The recovery is short lived Differs from extinction bursts which happen during extinction Renewal Reinstatement acquisition or a completely new different environment Concerned with environment context Change the context can go back to context from No time off after extinction During extinction now US or reinforce After extinction present US or a reinforcer Don t have to do behavior to get reinforce they get it Afterwards bring behavior back by continuing to for free reinforce it o Experiment spontaneous recovery Hungry rats learn CS food association 4 days of extinction training Split into 2 groups GR1 tested immediately the next day GR2 tested later 8 days later o Experiment Renewal Rats learn tone footshock association in context A Split into 3 groups CS tone US food shock Group 1 Extinction in context A Group 2 Extinction in context B Control group No extinction training Low numbers mean strong conditioned response 5 is maximum in conditioned suppression Measure conditioned suppression o Experiment Reinstatement Rats learn to bar press for cocaine Extinction Need to press a lot for it No cocaine will get frustrated and go through withdrawal then eventually stop responding Split into 3 groups group b c different experience with morphine than