Chapter 5 Learning

What is Learning?  A process that produces a relatively enduring change in behavior or knowledge as a result of past experience.  Conditioning—the process of learning the associations between environmental events and behavioral responses

Ivan Pavlov  Russian physiologist ( ).  Interested in the relationship between the nervous system and digestion.  Was studying salivation in dogs.

Classical Conditioning  Form of learning that involves repeatedly pairing a neutral stimulus with a response-producing stimulus until the nuetral stimulus elicits the same response.  Stimulus: Something that produces a reaction or a response.

Pavlov’s Dogs  Neutral Stimulus: Bell  Does not normally elicit a response or reflex action by itself.  A bell ringing  A color  A furry object

Unconditioned Stimulus– Food  UCS: Natural stimulus that reflexively elicits a response without the need for prior learning.  Always elicits a reflex action: an unconditioned response  Food  Blast of air  Noise

Unconditioned Response– Salivation  UCR: The unlearned, reflexive response that is elicited by an unconditioned stimulus  A response to an unconditioned stimulus—naturally occurring  Salivation at smell of food  Eye blinks at blast of air  Startle reaction in babies

Conditioned Stimulus– Bell  CS: A formerly neutral stimulus that acquires the capacity to elicit a reflexive response.  The stimulus that was originally neutral becomes conditioned after it has been paired with the unconditioned stimulus.  Will eventually elicit the unconditioned response by itself.

Conditioned Response  CR: The learned reflexive response to a conditioned stimulus.

Factors That Affect Classical Conditioning  Extinction: Gradual weakening and apparent disapearance of conditioned behavior.  Occurs when the conditioned stimulus is repeatedly presented without the unconditioned stimulus.  Spontaneous Recovery: Reappearance of a previously extinguished conditioned response after a period of time without exposure to the conditioned stimulus.

Factors That Affect Classical Conditioning  Stimulus Generalization: Occurrence of a learned response not only to the original stimulus but to other, similar stimuli as well.  Stimulus Discrimination: Occurrence of a learned response to a specific stimulus but not to other similar stimuli.  Higher order conditioning: Procedure in which a conditioned stimulus from one learning trial functions as the unconditioned stimulus in a new conditioning trial.  The second conditioned stimulus comes to elicit the conditioned response, even though it has never been directly paired with the unconditioned stimulus.  EX: Shots as a baby  Injection- UCS  Crying- UCR  Nurse white coat- CS  Crying and fear- CR  Baby then sees a cosmetic saleswoman who sprays perfume for mom. If the baby cries the next time she smells the perfume, then she has higher order conditioning.

Behaviorism  The attempt to understand observable activity in terms of observable stimuli and observable responses.  John B. Watson (1913)  B. F. Skinner (1938)

Little Albert  Wanted to prove that Classical Conditioning could elicit a conditioned emotional response in a human subject.  Assessed Albert at 9 month and he was normal and had no fear of rats, rabbits, dogs or monkeys.  Loud noises however did scare him (UCS)  11 months he was conditioned for fear the rat (CS)  Whenever he reached for the rat Watson clanged a steel bar with a hammer (UCS) and scared Albert (UCR)

Little Albert  First session he experienced two pairing of the rat with the loud noise  Week later he experienced five more pairings  After only these pairings Albert became afraid of just the rat (CR)  Stimulus generalization occurred– Albert was now afraid of the dog and rabbit.  Also afraid of cotton, Watson’s hair and Santa.

Cognitive Aspects of Classical Conditioning  Can have reliable and unreliable signals  If you approach a train track and lights flash before the train then you beging to pair flashing lights with a train.  If you approach a train track and the lights some times work and some times don’t than you don’t learn an associaiton.

Evolutionary Perspective  Conditioned taste aversion: Conditioned dislike for and avoidance of a particular food that develops when an organism becomes ill after eating the food.  Biological preparedness: idea that an organism is innately predisposed to form associations between certain stimuli and responses.  Can’t eat a hamburger but can eat Sonic  John Garcia—not all neutral stimuli can become conditioned stimuli.

E.L. Thorndike 1898  Law of effect: Responses followed by a satisfying effect become strengthened and are more likely to recur in a particular situation, while responses followed by a dissatisfying effect are weakened and less likely to recur in a particular situation. Scratch at bars Push at ceiling Dig at floor Situation: stimuli inside of puzzle box Howl Etc. Press lever First Trial in Box Scratch at bars Push at ceiling Dig at floor Situation: stimuli inside of puzzle box Howl Etc. Press lever After Many Trials in Box

B.F. Skinner and Operant Conditioning  Interested in emitted behaviors  Operant—voluntary response that acts on the environment to produce consequences.  Operant Conditioning: Basic learning process that involves changing the probability that a response will be repeated by manipulating the consequences of that response.

Reinforcement  The occurance of a stimulus or event following a response that INCREASES the likelihood of the response being repeated.

Positive vs. Negative Reinforcement  Positive: response if followed by the addition of a reinforcing stimulus, increasing the likelihood that the response will be repeated.  Negative: response results in the removal of, avoidance of, or escape from a punishing stimulus, increasing the likelihood that the response will be repeated.

Reinforcers  Primary—a stimulus that is inherently reinforcing for a species (biological necessities)  Food, water, and warmth  Conditioned (secondary)—a stimulus that has acquired reinforcing value by being associated with a primary reinforcer  Money, attention, social approval

Punishment Presentation of a stimulus following a behavior that acts to decrease the likelihood that the behavior will be repeated.  Phone taken away, probation

Punishment  Positive Punishment  Occurs when someone punishes a behavior by giving something.  If your little sister won’t stop crying you may spank her.  Negative Punishment  Occurs when someone punishes a behavior by taking something away.  If your little sister won’t stop crying you remove her from the situation.

Problems with Punishment  Does not teach or promote alternative, acceptable behavior  May produce undesirable results such as hostility, passivity, fear  Likely to be temporary  May model aggression

Discriminative Stimuli  A specific stimulus in the presence of which a particular response is more likely to be reinforced, an in the absence of which a particular response is not likely to be reinforced.  EX:  Discriminative Stimuli- Wallet on sidewalk  Operant Response- Give wallet to security  Consequence- $50 reward  Effect- Positive reinforcement

Operant Conditioning  Shaping: Selectively reinforcing successively closer approximations of a goal behavior until the goal behavior is displayed.  Tying shoe  Extinction: gradual weakening and disappearance of conditioned behavior.  Spontaneous recovery

Reinforcement Schedules  Continuous—every correct response is reinforced; good way to get a low-frequency behavior to occur  Partial—only some correct responses are reinforced; good way to make a behavior resistant to extinction

Partial Schedules- Ratio  Ratio schedules are based on the number of responses emitted.  Fixed ratio (FR)—a reinforcer is delivered after a certain (fixed) number of correct responses  FR10- Rat would have to press a lever 10 before he got a treat.  Variable ratio (VR)—a reinforcer is delivered after an average number of responses, but varies from trial to trial.  VR20- May push the bar 25 times and then 15

Partial Schedules- Interval  Interval schedules are based on time.  Fixed interval (FI)—reinforcer is delivered for the first response after a fixed period of time has elapsed.  FI2- Rat would receive no food for any bar presses before 2:00 but would receive for one after.  Variable interval (VI)—reinforcer is delivered for the first response after an average time has elapsed, differs between trials.  VI30: food after 10, 50 and 30 seconds for an average of 30seconds.

Cognitive Aspects of Operant Conditioning  Cognitive map—term for a mental representation of the layout of a familiar environment  Latent learning—learning that occurs in the absence of reinforcement, but is not demonstrated until a reinforcer is available  You may have learned something, but you don’t want to demonstrate the behavior until a reward is present  Reward motivates the performance  Learned helplessness—phenomenon in which exposure to inescapable and uncontrollable aversive events produces passive behavior  People learn that their behavior will have no effect on the environment  academics

Observational Learning  Observation  Modeling  Imitation  Must pay attention to the other person’s behavior  Must remember the other person’s behavior so that you can perform it later  Must transform this mental representation into actions that you are capable of reproducing  Must be a motivation for you to imitate the behavior  Reinforcement doesn’t have to be present for learning to occur  Albert Bandura