Introduction to Psychology Learning

Learning refers to an enduring change in the way an organism responds based on its experience –Distinct from Drug effects (caffeine-induced jitters are not learning) Fatigue or illness Three assumptions of learning theories –Responses are learned rather than innate –Learning is adaptive –Our experiments can uncover the laws of learning These laws will apply to animals and to humans

Classical Conditioning The Russian physiologist Pavlov noted that reflexive salivation in dogs could be elicited by stimuli associated with feeding –Reflex: Response that is reliably elicited by a stimulus Food elicits salivation Air puff elicits eye blink –Reflexive stimulus and response are unconditioned –Neutral stimulus is referred to as the conditioned stimulus (CS) –CS is paired with the UCS over many trials –Eventually comes to elicit a conditioned response (CR: resembles the UCR)

Pavlov’s Experiment

Acquisition and Extinction Acquisition of classical conditioning: –Repeated pairings of CS and UCS Extinction: Refers to the weakening of conditioning evident when the CS is presented repeatedly without the UCS –Spontaneous recovery: Refers to the reemergence of a previously extinguished CR

Stimulus Generalization and Discrimination Stimulus generalization occurs when an organism that has learned a response to a specific stimulus responds in the same way to new stimuli that are similar to the original stimulus. Stimulus discrimination occurs when an organism that has learned a response to a specific stimulus does not respond in the same way to new stimuli that are similar to the original stimulus.

Classical Conditioning Issues Temporal order of presentation of CS and UCS is important –Best conditioning: CS precedes UCS (forward) –Worst conditioning: UCS precedes CS (backward)

Conditioned Taste Aversion If a flavor is followed by an illness experience, animals will avoid the flavor in the future CS + UCS > UCR Taste Toxic event Nausea CS -----> CR FlavorNausea

Positive Reinforcement Reinforcer: An environmental stimulus that occurs after the response and increases the likelihood that the response will occur in the future –Positive reinforcement: Process by which presentation of a stimulus after a response makes the response more likely to occur in the future –Negative reinforcement: Termination of an aversive event makes a behavior more likely to occur in the future

Issues in Negative Reinforcement Negative reinforcement involves a situation in which a response that terminates an aversive stimulus will strengthen that response –Taking an aspirin will reduce the headache and strengthen the behavior of aspirin-taking (sometimes referred to as escape-learning) –Avoidance learning: A response prevents a potentially aversive event from occurring Child cleans his room to avoid parental nagging

Punishment Punishment decreases the likelihood that a response will occur Examples of punishing situations –Presentation of an aversive stimulus (Positive) Parent spanks a child for taking candy... Owner swats a dog who has chewed her slippers... –Removal of a reward (Negative) Teenager who stays out past curfew is not allowe d to drive the family car for 2 weeks... Husband who forgets anniversary sleeps on couch for a week...

Difficulties in Punishment Learner may not understand which operant behavior is being punished Learner may come to fear the teacher, rather than learn an association between the action and punishment (then avoids the teacher) Punishment may not undo existing rewards for a behavior Using punishment when the teacher is angry Punitive aggression may lead to future aggression

Schedules of Reinforcement Continuous reinforcement: Reinforcer is obtained for every response –Intermittent schedules: Reinforcer is not obtained for every response Ratio Schedules –Fixed Ratio: Every Nth response –Variable Ratio: The average is every Nth response Interval Schedules: –Fixed Interval: After the elapse of N minutes –Variable Interval: On average, after N minutes

Impact of Schedules of Reinforcement on Behavior

Observational Learning Social Learning Theory (Bandura) Modeling Vicarious learning Acquisition vs. Performance