LEARNING Chapter 5 CLASSICAL CONDITIONING LEARNING THROUGH ASSOCIATION

LEARNING Chapter 5

CLASSICAL CONDITIONING: LEARNING THROUGH ASSOCIATION Chapter 5 Section 1

Introduction • Do your muscles tighten at the sound of a dentist’s drill? • Do you suddenly begin to salivate when passing your favorite restaurant? • You weren’t born with these responses - you learned them.

Introduction • Learning- a relatively permanent change in behavior acquired through experience. • To understand learning, we need to consider the work of the Russian physiologist Ivan Pavlov (1849 -1936). • Pavlov discovered the form of learning we call classical conditioning.

Introduction • Classical conditioning is the process of learning by which a previously neutral stimulus comes to elicit a response identical or similar to one that was originally elicited by another stimulus as the result of the pairing or association of the two stimuli. • Ex. Pavlov rang a bell and then presented his dogs with food. Over time, when the dogs heard the bell, they salivated, knowing they would be fed.

Introduction • Because of past experiences, we are conditioned to react in certain ways based on those experiences. • Although classical conditioning is a relatively simple form of learning, it plays an important role in our lives.

Principles of Classical Conditioning • Pavlov performed many experiments in classical conditioning. • He placed food on a dog’s tongue to create natural salivation. • This reflexive behavior is known as unconditioned response (UR)- an unlearned response to a stimulus.

Principles of Classical Conditioning • In this instance the unconditioned stimulus (US), the stimulus that elicits an unconditioned response, is the dog food.

Principles of Classical Conditioning

Principles of Classical Conditioning • In the 2 nd trial, there is the introduction of a neutral stimulus (NS), a stimulus that before conditioning does not produce a particular response. • The NS may elicit other reactions (dog’s ears turning up), but it does not salivate due to the buzzer or bell. • However, repeated pairings of the NS and the unconditioned stimulus (US), the dog acquires a learned response: salivation at the tone or buzzer alone.

Principles of Classical Conditioning • Salivation to the sound of a tone or buzzer alone is an example of a conditioned response (CR)- an acquired or learned response to a conditioned stimulus. • A previously neutral stimulus becomes a conditioned stimulus (CS)- a previously neutral stimulus that comes to elicit a conditioned response after it has been paired with an unconditioned stimulus.

Principles of Classical Conditioning • Pavlov observed that the strength of the conditioned response (amount of saliva) increased with the number of pairings of the CS and US.

Principles of Classical Conditioning

Principles of Classical Conditioning

Extinction and Spontaneous Recovery • Pavlov also noticed that the conditioned response would gradually weaken over time when he repeatedly presented the tone in absence of the US (food). • Extinction- The gradual weakening and eventual disappearance of a conditioned response.

Extinction and Spontaneous Recovery • The extinguished response is not forgotten or lost to memory, it may return spontaneously at a later time when the animal is again exposed to the conditioned stimulus • Spontaneous recovery- The spontaneous return of a conditioned response following extinction. • The recovered response will once again extinguish as the CS occurs in the absence of the US.

Extinction and Spontaneous Recovery • Pavlov discovered that when the CS and US are paired again after extinction, the response is likely to be learned more quickly than in original conditioning. • In many cases, the animal needs only one or two pairings. • Reconditioning- the process of relearning a conditioned response following extinction.

Stimulus Regeneration and Stimulus Discrimination • Pavlov also found that once the dogs were conditioned to salivate at the sound of a tone would also salivate (although less so) at the sound of a related stimuli (such as a different pitch). • This is known as stimulus generalizationthe tendency for stimuli that are similar to the conditioned stimulus to elicit a conditioned response.

Stimulus Regeneration and Stimulus Discrimination • Stimulus generalization has survival value because it allows us to respond to a range of stimuli that are similar to an original threatening stimulus • Ex. Bitten by a large dog when you were young and now you tense up when you see a large dog coming. Not all dogs are dangerous, but stimulus generalization prepares us just in case.

Stimulus Regeneration and Stimulus Discrimination • Stimulus generalization can also help explain feelings of déjà vu. • The feeling of familiarity in novel situations may involve a process of conditioning in which responses are evoked by generalization stimuli in these new environments that resemble conditioned stimuli encountered before.

Stimulus Regeneration and Stimulus Discrimination • Stimulus discrimination- the ability to differentiate among related stimuli, represents the opposite side of the coin to stimulus generalization. • Ex. If an animal is being tested and is given a shock after hearing a certain tone, the animal will become afraid after it hears the tone (cowers or urinates). Even if the tone is heard and no shock is given, the animal will become scared, but if a different tone is played (similar to the fear inducing one) the animal will remain calm.

Stimulus Regeneration and Stimulus Discrimination • Stimulus discrimination in daily life allows us to differentiate between threatening and nonthreatening stimuli. • Ex. Through repeated non-eventful encounters with the Labrador who lives next door, we understand that we may only need to react with fear to unfamiliar large dogs.

Stimulus Regeneration and Stimulus Discrimination Conditioned Stimulus A large white dog Conditioned Response Child displays fear Stimulus Generalization The child cringes when a small, white dog appears Stimulus Discrimination The child shows no Fear of a small, brown dog

Stimulus Characteristics That Strengthen Conditioned Responses • Psychologists have identified several key factors relating to the timing and intensity of stimuli that serve to strengthen conditioned responses: • Frequency pairings- The more often the CS is paired with the US, the stronger and more reliable the CR will be. • Timing- The strongest CRs occur when the CS is presented first and remains present throughout the administration of the US

Stimulus Characteristics That Strengthen Conditioned Responses • Intensity of US- A stronger US will typically lead to faster conditioning than a weaker one. • Ex. A puff of air (US) may be delivered after a tone. The puff will produce a blink (UR). After a few pairings, you will blink (CR) once you hear the tone (CS) alone. A stronger air puff will lead to faster conditioning.

A Cognitive Perspective on Classical Conditioning • Psychologist Robert Rescola argued that conditioning depends on a cognitive factor- the informational value of a conditioned stimulus as a reliable signal for predicting the occurrence of the US. • Humans and animals actively seek information that helps them make predictions about important events in their environments. • Ex. If an animal catches a scent known to be associated with a predator, it can respond quicker and leave the situation.

Why It Matters • Classical conditioning helps us explain such diverse behaviors as phobias, drug cravings, and taste aversions. • In 1919, John B. Watson discovered that fear response could be acquired through classical conditioning.

Classical Conditioning of Fear Response • http: //www. youtube. com/watch? v=Xt 0 ucx. Or. PQE&safety_ mode=true&safe=active&persist_safety_mode=1 • Before Conditioning- Child shows no fear of white rat. • During Conditioning- White rat (CS) is paired with loud sound (US) that naturally evokes fear response.

Classical Conditioning of Fear Response • After Conditioning- Child shows fear (CR) of white rate alone (CS). • Stimulus Generalization- Child shows fear reaction (CR) to related stimulus. • Findings have helped explain phobias and the development of therapy known as behavior therapy (OCD/phobias).

Classical Conditions of Positive Emotions • Classical Conditioning can also be used for positive feelings. • Hearing a sound may evoke past experiences associated with pleasant emotions. • Feelings of nostalgia may be brought up by something as simple as catching a whiff of a familiar perfume or cologne.

Classical Conditioning of Drug Cravings • Drugs cravings may be elicited by cues in the environment that were associated with previous drug use. • Ex. A former alcoholic may experience strong cravings when they pass a bar or meet up with former friends whom they’ve drank with. • Cravings may represent conditioned responses that continue to be elicited long after the physiological signs of withdrawal have passed.

Classical Conditioning of Drug Cravings • Studies have shown that people with alcoholism salivate more at the sight and odor of alcohol than nonalcoholic subjects. • Drug counselors encourage recovering alcoholics and drug addicts to avoid cues associated with their former drug use patterns.

Classical Conditioning to Taste Aversion • Psychologist John Garcia was the first to demonstrate experimentally the role of classical conditioning in the acquisition of taste aversions. • Garcia noticed that lab rats developed an aversion, or “conditioned nausea” to flavored water when it was coupled with nausea-producing radiation. • The radiation is the US; the nausea it produces is the UR; the flavored water is the CS; and the aversion (nausea) the CS elicits on its own is the CR.

Classical Conditioning to Taste Aversion • What Garcia also found is that the US (nausea inducing stimulus) could be presented hours after the CS (food taste) and still have the same result. • What does this mean? Prior to this, it was thought that the US had to immediately follow or precede the CS to give the intended results. • This explains why we may shy away from foods that we’ve eaten prior to getting sick (either from food poisoning or other reasons).

Classical Conditioning to Taste Aversion • Taste aversion has practical uses for survival as well. • Ex. Our ancestors lived without refrigeration or preservatives. When they ran across rancid smells and the ensuing tastes sickened them, they knew not to eat foods that smell like that in the future. • Ex. Injecting sheep carcasses with poison so that coyotes would stop attacking live sheep.

OPERANT CONDITIONING: LEARNING THROUGH CONSEQUENCES Chapter 5 Section 2 http: //www. youtube. com/watch? v=DUa_F 2 OJT 0 k&safety_mode=tr ue&safe=active&persist_safety_mode=1 http: //www. youtube. com/watch? v=t. MMNkxx. XVKI&safety_mode=tru e&safe=active&persist_safety_mode=1

Introduction • Whereas classical conditioning explores learning that results from association between stimuli before a response occurs, operant conditioning explores learning that results from the association of a response with its consequences. • Responses are acquired and strengthened by the effects they produce in the environment.

Thorndike and the Law of Effect • Edward Thorndike (1874 -1947) constructed a device called a “puzzle box”- a cage in which an animal (usually a cat) had to perform a simple act (pulling a looped string or pushing a pedal) in order to make its escape and reach a food dish placed within its view just outside the cage.

Thorndike and the Law of Effect • The animal would first engage in seemingly random behaviors until accidentally performing the response that released the door. • Thorndike argued that the animals did not employ any reasoning, insight, or any other form of higher intelligence. • He said it was through trial and error that they chanced upon their successful behavior.

Thorndike and the Law of Effect • Successful responses were then “stamped in” by the pleasure they produced and became more likely to be repeated in the future. • Based on his observations, Thorndike proposed the Law of Effect- responses that have satisfying effects are more likely to recur (reward), while those that have unpleasant effects are less likely to recur (punishment). • http: //www. youtube. com/watch? v=fanm-- Wy. QJo&safety_mode=true&safe=active&persist_safety_mode=1

B. F. Skinner and Operant Conditioning • http: //www. youtube. com/watch? v=SUw. Cg. FSb 6 Nk&safety_mode=true&safe= active&persist_safety_mode=1 • Though Thorndike laid the foundation for learning through consequences, it was B. F. Skinner (1904 -1990) who developed a more formal model of this type of learning, which he called operant conditioning. • Skinner was the most famous psychologist of his time, but he was also the most controversial.

B. F. Skinner and Operant Conditioning • Skinner believed in radical behaviorism, which says that behavior, whether animal or human, is completely determined by environmental and genetic influences. • Free will, according to Skinner, is but an illusion. • Skinner was different from Pavlov in that he wanted to understand how new behaviors were learned.

B. F. Skinner and Operant Conditioning • Skinner developed the Skinner box, which was a cage that contains a food-release mechanism the animal activates when it responds in a certain way- ex. Pressing a lever or pushing a button. • http: //www. youtube. com/watch? v=I_ct. Jqjlr. HA&safety_mode=true&safe=activ e&persist_safety_mode=1 • Operant conditioning is also called instrumental learning since the behavior is instrumental in bringing about rewarding consequences. • These behaviors have a reinforcer- a stimulus or event that increases the likelihood that the behavior it follows will be repeated.

B. F. Skinner and Operant Conditioning • Skinner observed that the longer the reinforcement is delayed, the weaker its effects will be. • Skinner also showed how operant conditioning can explain some forms of superstitious behavior. • Ex. A baseball player who hits a homerun after a long slump and then wears the same pair of socks he had on at the time for good luck in the rest of his games.

Positive and Negative Reinforcement • Positive reinforcement- A response is strengthened by the introduction of a stimulus after the response occurs. • Ex. You are more likely to continue to study if you see your efforts rewarded in the form of good grades. If you study and fail, you are less likely to continue to study. • Negative reinforcement- A response is strengthened when it leads to the removal of an “aversive” (unpleasant or painful) stimulus. • Ex. A parent picks up a crying baby to comfort it is negatively reinforced when the baby stops crying because the aversive stimulus (crying) is being taken away.

Positive and Negative Reinforcement • The difference between the two is that in the positive reinforcement, behaviors are strengthened when they are followed by the introduction of a stimulus, whereas in negative reinforcement, behaviors are strengthened when they lead to the removal of a stimulus.

Positive and Negative Reinforcement • Negative reinforcement can have undesired effects in some situations. • Ex. A child throws a tantrum in a store because he/she wants a certain toy. The child may have learned that throwing a tantrum will get the results he/she desires. In operant learning terms, when the tantrum gets results, the child is positively reinforced (because the parent “gives in”), while the parent is negatively reinforced for complying with the child’s demands because the tantrum stops. Because it is handled this way, tantrums will occur more frequently.

Primary and Secondary Reinforcers • Primary reinforcers- Rewards that satisfy basic biological needs and drives. • Ex. Food, water, sleep, relief from pain or loud noise, oxygen, sexual stimulation, and novel visual stimuli. • Secondary reinforcers- Reinforcement through a learning process by which they become associated with primary reinforcers. • Ex. Money is a secondary reinforcer because it acquires reinforcement value because we learn it can be exchanged for more basic reinforcers (food, clothing, etc. )

Primary and Secondary Reinforcers • Other types of secondary reinforcers include good grades, awards, and praise. • Much of our daily behavior is influenced by secondary reinforcers in the form of expressions of approval from others.

Discriminative Stimulus • Discriminative stimulus- A cue that signals that reinforcement is available if the subject makes a particular response. • Ex. When is it better to ask someone for a favor, when someone appears to be down in the dumps or when someone is smiling? We know the answer because we know that facial cues serve as discriminative stimuli that signal times when requests will likely be positively received. • Ex. A green traffic light is discriminative stimulus in that it signals that driving through an intersection is likely to be safe.

Shaping • Shaping- The process of learning that involves the reinforcement of increasingly closer approximations of the desired response. • Ex. The experimenter may reinforce the rat when it moves to the part of the cage that contains the bar.

Shaping • Then reinforcement only occurs when the rat moves closer to the bar until it actually presses the bar. • Ex. Think of how we solve multi-step math problems.

Schedules of Reinforcement • One of Skinner’s major contributions was showing how schedules of reinforcement- predetermined plans for timing the delivery of reinforcement - influence learning. • Schedule of Continuous Reinforcement- Reinforcement follows each instance of operant response.

Schedules of Reinforcement • Most rapid way of learning, but is the quickest way to extinction when reinforcement is withheld. • Ex. Every time the rat presses the lever, it gets food.

Schedules of Reinforcement • Schedule of Partial Reinforcement- Only a portion of responses are reinforced. • Response takes longer to fade out because absence of reinforcement is unlikely to be noticed.

Schedules of Reinforcement • 2 types of partial reinforcement: • Ratio schedules- reinforcement is based on the number of responses • Interval schedules- reinforcement based on the timing of responses • For each, reinforcement can be administered on either fixed or variable basis.

Fixed-Ratio (FR) Schedule • Reinforcement is given after a certain number of responses. • FR schedules produce a constant, high level of response, with a slight dip in responses occurring after each reinforcement. • Ex. The faster people work, the more items they produce and the more money they earn, but quality may suffer. • www. betabunny. com/behaviorism/FRS. htm

Variable Ratio (VR) Schedule • Reinforcement is given at varying times throughout the schedule. • Produces high, steady rates of response. • Ex. If VR is 20, reinforcement is given after an average of every 20 responses.

Variable Ratio (VR) Schedule • Ex. Gambling on slot machines may win (reinforcement) may occur after different numbers of tries. • www. betabunny. com/behaviorism/VRS. htm

Fixed-Interval (FI) Schedule • Reinforcement is given only for a correct response made after a fixed amount of time has elapsed since the last reinforcement. • Produces a “scalloped” pattern in which the rate of response typically dips just after reinforcement and then increases as the end of the interval approaches.

Fixed-Interval (FI) Schedule • Ex. Workers who receive monthly performance reviews may show more productive behaviors in the days leading up to their evaluations than immediately afterward (cops and speeding tickets at end of the month). • http: //www. betabunny. com/behaviorism/FIS. htm

Variable-Interval (VI) Schedules • Reinforcement is given after a specific amount of time has elapsed. • Produces a slow but steady rate of response and tends to be more resistant to extinction than on a FI schedule.

Variable-Interval (VI) Schedules • Ex. If the VI is 60, reinforcement is given after an average of 60 seconds has elapsed (could be as short as 1 sec. or as long as 120 sec. ). • Ex. Teachers use surprise “pop” quizzes to encourage regular study habits.

Escape Learning and Avoidance Learning • Escape learning- Learning behaviors that allow an organism to escape from an aversive stimulus. • Ex. We escape from heat of a summer day by turning on a fan or air conditioning. • Avoidance Learning- The organism learns to perform a response that avoids an aversive stimulus. • Ex. We open an umbrella before stepping outside into rain to avoid the unpleasantness of being drenched.

Punishment • Skinner observed that behaviors that are not reinforced or that are punished are less likely to be repeated. • Punishment is the flip side to reinforcement. • Punishment is different than negative reinforcement in that punishment is the introduction of an aversive stimulus or negative consequence (e. g. a timeout) after a behavior that occurs weakens or suppresses the behavior.

Punishment • Negative reinforcement is the removal of an aversive stimulus (a baby’s crying) after a behavior occurs strengthens the behavior (picking up the baby). • Psychologists and pediatricians encourage parents not to rely on punishment, but they recommend reinforcing desirable behaviors. • Punishment is more effective when combined with positive reinforcement for desirable alternative behaviors.

Behavior Modification: Putting Learning Principles into Practice • Behavior modification (B-mod): The systematic application of learning principles to strengthen adaptive behavior and weaken maladaptive behavior. • Skinner and his colleagues used the first token economy program in a mental hospital. • Token Economy- tokens were earned for performing desired behaviors can be exchanged for positive reinforcers (extra privileges).

Programmed Instruction • Programmed Instruction- A learning method in which complex material is broke down into a series of small steps that learners master at their own pace. • Over the years, this has given way to computer-assisted instruction, in which a computer guides students through an inventory of increasingly more challenging questions.