Learning

Stimulus or Stimuli Any event or object in the environment to which an organism responds

Learning Relatively permanent change in behavior, knowledge, capability, or attitude acquired through experience & cannot be attributed to illness, injury, or maturation Why injury? Like when your behavior may change because you’ve had a brain injury. Why maturation? Like when you talk in a deeper voice as a result of puberty.

Classical Conditioning A stimulus comes to predict the occurrence of another stimulus and elicits a response similar to the response related by that stimulus. A cat salivates when they see and smell their food; tap the can every time you are about to feed your cat & they will start to salivate when they hear the tapping.

Ivan Pavlov (1849-1936) Russian scientist, studied physiology of digestion, won Nobel Prize in 1904 Major contribution was the study of the conditioned reflex, which provided a model of learning called classical conditioning Used dogs & a bell

Elements of Classical Conditioning Stimulus & Response Reflex: an involuntary response to a particular stimulus (eyeblink, salivation) 2 kinds of reflexes: conditioned & unconditioned OR learned & unlearned Unconditioned response (UR): response that is invariably elicited by the US without prior learning Unconditioned stimulus (US): elicits a specific response without prior learning Conditioned stimulus (CS): neutral stimulus after repeated pairing becomes associated with & elicits a conditioned response Conditioned response (CR): response that comes to be elicited by a conditioned stimulus as a result of repeated pairing with US

Extinction & Spontaneous Recovery Extinction: weakening & eventual disappearance of a learned response Spontaneous recovery: reappearance of an extinguished response

Generalization In classical conditioning, the tendency to make a conditioned response to a stimulus similar to the original conditioned stimulus

Discrimination Learned ability to distinguish between similar stimuli so the conditioned response occurs only to the original conditioned stimulus but not the similar stimuli

Higher Order Conditioning Conditioning that occurs when a neutral stimulus is paired with an existing conditioned stimulus, becomes associated with it, and gains the power to elicit the same conditioned response For example, Pavlov could flash a light along with the tone he played & then the light flashing would also become associated with the stimulus

John Watson (1878-1958) Demonstrated that fear could be classically conditioned by presenting a white rat along with a loud, frightening noise, thereby conditioning Little Albert to fear the white rat. Fear generalized to a dog, a seal coat, Watson’s hair, and a Santa Claus mask Formulated techniques to remove a conditioned fear

Classical Conditioning: Modern View Rescorla: predicting the occurrence of the unconditioned stimulus Rat experiment: tone (CS) & shock (US) = predict response BUT tone (CS) & shock (US) AND no shock (US) = not predictable response

Blocking When previous conditioning to one stimulus prevents conditioning to a second stimulus with which it has been paired Tone (CS), then Light (CS), but tone “trumped” CR because it was learned first, light (CS) was “blocked”

Taste Aversions Intense dislike and/or avoidance of a particular food that have been associated with pain or discomfort Can be generalized Chemotherapy: “scapegoat” food before treatment

Everyday Classical Conditioning Many emotional responses result from classical conditioning (positive and negative) Fears & Phobias / dentist’s office Drug Use / cues / soldiers & heroin use in Vietnam Advertisements

Factors Influencing Classical Conditioning How reliable a conditioned stimulus predicts the unconditioned response The number of pairings of the conditioned stimulus and the unconditioned stimulus Intensity of the unconditioned stimulus Temporal relationship between the conditioned stimulus and the unconditioned stimulus

Operant Conditioning The consequences of behavior are manipulated in order to increase or decrease that behavior in the future. Voluntary responses (not reflexive) Active state Simple to highly complex responses

Thorndike & the Law of Effect Edward Thorndike (1874-1949) Trial-and-error learning: occurs when a response is associated with a successful solution to a problem after a number of unsuccessful responses. Cats in the puzzle box, hitting lever for food Law of effect: connection between a stimulus & response will be strengthened if the response is followed by a satisfying consequence or weakened it causes discomfort.

B.F. Skinner: Operant Conditioning Pioneer Burrhus Frederic Skinner (1904-1990) Believed behavior was shaped by the environment Response first, then consequence Skinner box: soundproof chamber with a device for delivering food & either a bar for rats to press or a disk for pigeons to peck

Shaping An operant conditioning technique that consists of gradually molding a desired behavior (response) by reinforcing responses that become progressively closer to it

Extinction Weakening & often eventual disappearance of a learned response (in operant conditioning, the conditioned response is weakened by withholding reinforcement)

Generalization In operant conditioning, the tendency to make the learned response to a stimulus similar to the one that was originally reinforced

Discriminative stimulus A stimulus that signals whether a certain response or behavior is likely to be followed by reward or punishment

Reinforcement An event that follows a response and increases the strength of the response and/or the likelihood that it will be repeated

Positive Reinforcement A reward or pleasant consequence that follows a response and increases the probability that the response will be repeated

Negative Reinforcement The termination of an unpleasant stimulus after a response in order to increase the probability that the response will be repeated

Primary Reinforcer A reinforcer that fulfills a basic physical need for survival & does not depend on learning Eating, sleeping, drinking, stopping pain, & having sex

Secondary Reinforcer A neutral stimulus that becomes reinforcing after repeated pairings with other reinforcers Money, praise, good grades, attention, approval

Continuous Reinforcement Administered after every desired or correct response; the most effective method of conditioning a new response Rat got food every time it pressed bar

Partial Reinforcement Pattern of reinforcement in which some portion, rather than 100%, of the correct responses are reinforced More like real life, partial reinforcement is the rule

Schedule of Reinforcement Systematic program for administering reinforcements that has a predictable effect on behavior Distinct rates & patterns of responses

Fixed-Ratio Schedule A fixed number of correct responses Rat receives food after 5 pushes of lever What would happen if the ratio was 100 pushes for each pellet of food? If it was 1,000?

Variable-Ratio Schedule Reinforcer is given after a varying number of nonreinforced responses based on an average ratio Rat gets food after 30 lever pushes, then 20 pushes, then 50… averages to VR of 30 Higher, more stable rates of responding than fixed-ratio schedules

Variable-Ratio Schedule Real life example: Casino gambling Variable-ratio: highest response rate & most resistance to extinction

Fixed-Interval Schedule Reinforcer is given following the first correct response after a fixed period of time has elapsed Working on salary: fixed-interval schedule Food given every 60 seconds

Variable-Interval Schedule Reinforcer is given after the first correct response following a varying time of nonreinforcement based on an average time. Pop quizzes, cannot predict, so study responses should be more uniform

Partial Reinforcement Effect Greater resistance to extinction Reward not expected every time, so the learning does not become extinct Strongest resistance to extinction observed by Holland & Skinner (1961): Fixed ratio of 900, pigeon emitted 73,000 responses during the first 4 ½ hours of extinction Why parents should not give into nagging.

Influencers in Operant Conditioning Magnitude Immediacy Level of motivation of the learner

Punishment vs. Negative Reinforcement Punishment: adds a negative condition Reinforcement: removes a negative condition Punishment: Discourages a behavior Reinforcement: Encourages a behavior

Problems with punishment Does not extinguish undesirable behavior, it suppresses that behavior when they are being punished Does not help people develop more appropriate behaviors Often causes fear & anger Can lead to aggression

Effective Punishments Timing Intensity Consistency

Escape & Avoidance Learning Escape learning: performing a behavior because it terminates an aversive event (running away, taking medicine) Avoidance learning: first, an event signals a bad situation (classical conditioning); second, you avoid that situation (operant conditioning, negative reinforcement)

Learned Helplessness A passive resignation to aversive conditions learned by repeated exposure to aversive events that are inescapable and unavoidable Dogs; abused women

Applications Training Animals Biofeedback Behavior modification

Learning by Insight: Aha! Wolfgang Köhler (1887-1967) Chimps, bananas, sticks, boxes & a flash of insight (not trial-and- error) Solution gained through insight is more easily learned, less likely forgotten & more readily applied to new problems

Latent Learning & Cognitive Maps Edward Tolman (1886-1959) Latent learning: occurs without apparent reinforcement but is not demonstrated until sufficient reinforcement is provided Rats, mazes, one rewarded, one not, one rewarded later. Cognitive map: mental representation of a spatial arrangement

Observational Learning Albert Bandura (1925-present) Observational learning or modeling: learning by watching the behavior of others & the consequences of that behavior; learning by imitation Fears acquired by observing behavior Aggression acquired by observation