Learning

Chapter Five

Lecture Slides

By Glenn MeyerTrinity University

Introduction: What Is Learning?Conditioning is the process of learning associations between environmental events and behavioral responses.• Classical conditioning explains

how certain stimuli can trigger an automatic response.

• Operant conditioning is useful in understanding how we acquire new, voluntary actions.

• Observational learning is when we acquire new behaviors by observing the actions of others.

Learning refers to a relatively

enduring change in behavior or

knowledge as a result of

experience.

Classical ConditioningDiscovered by Ivan Pavlov while studying digestion

Classical conditioning: the

basic learning process that

involves repeatedly pairing a neutral stimulus with a response-

producing stimulus until the neutral

stimulus elicits the same response

Principles of Classical Conditioning

Basic Principles of

Classical Conditioning

Involve…Click here

Two stimuli are repeatedly

paired.

After repeated pairings, neutral stimulus elicits

same basic reflexive response as the natural stimulus.

This occurs in the absence of the natural

stimulus.

Pairing a neutral stimulus with an

unlearned, natural stimulus that

automatically elicits a reflexive response.

Unconditioned stimulus (UCS): natural stimulus that reflexively elicits a response without need for prior learning. Meat

Unconditioned response (UCR): unlearned, reflexive response that is elicited by an unconditioned stimulus. Salivating to meat

Conditioned stimulus (CS): a formerly neutral stimulus that acquires the capacity to elicit a reflexive response. Bell presented before meat

Conditioned response (CR): learned, reflexive response to a conditioned stimulus. Salivating to bell alone

Unconditioned StimulusClick here

Unconditioned ResponseClick here

Conditioned StimulusClick here

Conditioned ResponseClick here

The occurrence of a learned response not only to the original stimulus but to other, similar stimuli as well

Example: Conditioned to salivate to a low-pitched tone, a dog will also salivate to a slightly higher-pitched tone.

Stimulus generalizationCLICK HERE

The occurrence of a learned response to a specific stimulus but not to other, similar stimuliExample: Give a dog some food following a high-pitched tone but don’t give the dog any food following a low-pitched tone. The dog learns to salivate to the high-pitched tone but not to the low-pitched tone.

Stimulus discriminationCLICK HERE

Procedure in which a conditioned stimulus from one learning trial functions as the unconditioned stimulus in a new conditioning trial; second conditioned stimulus comes to elicit the conditioned response, even though it has never been directly paired with unconditioned stimulus.Example: Pairing a metronome and a shock causes a dog to be scared of the metronome. Then pairing a bell with the metronome makes the dog fear the bell.

Higher order conditioningCLICK HERE

Factors that Affect Conditioning

Timing• Conditioning most effective when conditioned

stimulus is presented immediately before unconditioned stimulus

• Usually ½ second to a few seconds

Extinction and Spontaneous RecoveryExtinction

• Gradual weakening and apparent disappearance of conditioned behavior

• In classical conditioning, extinction occurs when conditioned stimulus is repeatedly presented without unconditioned stimulus

Spontaneous Recovery

Reappearance of a previously

extinguished conditioned response after a period without

exposure to conditioned stimulus

From Pavlov to Watson

Behaviorism was founded by John Watson, who redefined psychology as the scientific study of behavior

The Founding of Behaviorism

Behaviorism

School of psychology and theoretical viewpoint that emphasizes the scientific study of observable behaviors, especially as they pertain to the process of learning

Let us limit ourselves to things that can be observed, and formulate laws concerning only those things. Now what can we observe? We can observe behavior—what the organism does or says.

Psychology as the behaviorist views it is a purely objective experimental branch of natural science. Its theoretical goal is the prediction and control of behavior. Introspection forms no essential part of its methods, nor is the scientific value of its data dependent upon the readiness with which they lend themselves to interpretation in terms of consciousness.

I should like to go one step further now and say, “Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I’ll guarantee to take any one at random and train him to become any type of specialist I might select—doctor, lawyer, artist, merchant-chief and yes, even beggar-man and thief— regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors.” I am going beyond my facts and I admit it, but so have the advocates of the contrary and they have been doing it for many thousands of years.

Conditioned Emotional ReactionsThe Famous Case of Little Albert – Was It Ethical?

Other Classically Conditioned Responses

Drug Responses Regular use may produce “placebo

response” where user associates sight, smell, taste with the drug effect

Conditioned compensatory response (CCR)—classically conditioned response in which stimuli that reliably precede the administration of a drug elicit physiological reaction that is opposite to the drug’s effects; may be one explanation for the characteristics of withdrawal and tolerance

The Smell of Coffee

Contemporary Views of Classical Conditioning

Rescorla’s view

Pavlovian conditioning is a sophisticated and sensible mechanism by which organisms represent the world. Pavlovian conditioning leads to its characterization as a mechanism by which the organism encodes relationships between events in the world. The conditioned stimulus and the unconditioned stimulus are simply two events, and the organism can be seen as trying to determine the relationship between them.

Contemporary learning researchers

acknowledge the importance of both

cognitive factors and evolutionary influences in classical conditioning.

Reliable and unreliable signals need processing:• Conditioned stimulus must be

a reliable signal that predicts presentations of unconditioned stimulus.

• Active processing of information: animals assess the predictive value of stimuli.

Cognitive Aspects of Classical Conditioning

Evolutionary Aspects of Classical Conditioning• Behaviorists originally argued that

learning principles applied to all species in the 1960s.

• Conditioned taste aversions demonstrated the importance of natural behavior patterns influenced by evolution.

• Discovered by John Garcia: A classically conditioned dislike for and avoidance of a particular food that develops when an organism becomes ill after eating the food.

• Violates standard conditioning model• Only needs one pairing • Time between CS and UCS can be

several hours• Particular conditioned stimulus that is

used makes a difference in classical conditioning

Evolution, Biological Preparedness, and Conditioned FearsWhat Gives You the Creeps?

Biological preparedness—the idea that an organism is innately predisposed to form associations between certain stimuli and responses.

Seligman• Phobias seem to be quite

selective. Extreme, irrational fears of snakes, spiders, heights, and small enclosed places are relatively common.

• Humans biologically prepared to develop fears of objects or situations such as snakes, spiders, and heights—that may once have posed a threat to humans’ evolutionary ancestors.

BregmanUnable to produce a conditioned fear response to wooden blocks and curtains.Öhman and MinekaBecause poisonous snakes, reptiles, and insects have been associated with danger throughout the evolution of mammals, there is an evolved “fear module” in the brain that is highly sensitized to such evolutionarily relevant stimuli.

Operant Conditioning—Associating Behaviors and ConsequencesOperant conditioning deals with the learning of active, voluntary behaviors that are shaped and maintained by their consequences.

Major Figures:Edward Lee

Thorndike (left)

Burrhus Frederic Skinner (right)

Thorndike and the Law of Effect• Cats had to escape from

a “puzzle” box• Process was by trial and

error• Observation led to Law of

Effect

Responses followed by a “satisfying state of affairs” are “strengthened” and more likely to occur again in the same situation. Conversely, responses followed by an unpleasant or “annoying state of affairs” are “weakened” and less likely to occur again.

Scratch at bars

Push at ceiling

Dig at floorSituation:stimuliinside ofpuzzle box

Howl

Etc.

Etc.

Press lever

First Trialin Box

Scratch at bars

Push at ceiling

Dig at floorSituation:stimuliinside ofpuzzle box

Howl

Etc.

Etc.

Press lever

After ManyTrials in Box

B. F. Skinner and the Search for “Order in Behavior”

• Believed that psychology should restrict itself to studying only phenomena that could be objectively measured and verified—outwardly observable behavior and environmental events

• Believed that internal thoughts, beliefs, emotions, or motives could not be used to explain behavior

• Coined the term operant to describe any “active behavior that operates upon the environment to generate consequences

• Invented the Skinner box

ReinforcementOperant conditioning explains learning as a process in which behavior is shaped and maintained by its consequences. One possible consequence of a behavior is reinforcement. Reinforcement is said to occur when a stimulus or an event follows an operant and increases the likelihood of the operant being repeated.

Positive reinforcement involves following an operant with the addition of a reinforcing stimulus. In positive reinforcement situations, a response is strengthened because something is added or presented.

Negative reinforcement involves an operant that is followed by the removal of an aversive stimulus. In negative reinforcement situations, a response is strengthened because something is being subtracted or removed.

Aversive stimuli involve physical or psychological discomfort that an organism seeks to escape or avoid. Behaviors are said to be negatively reinforced when they let you either

(1) Escape aversive stimuli that are already present, or

(2) Avoid aversive stimuli before they occur.

Primary and Conditioned Reinforcers

Primary reinforcer: a stimulus that is inherently reinforcing for a species (biological necessities)

Examples: food, water, comfort, pain relief, sexual contact

Conditioned (or secondary) reinforcer: a stimulus that has acquired reinforcing value by being associated with a primary reinforcer

Classic example: money

Punishment• Process in which a behavior is followed by an aversive consequence that

decreases the likelihood of behavior’s being repeated • Many people confuse punishment and negative reinforcement.• Two types of punishment identified by Skinner

• Punishment by application: a situation in which an operant is followed by presentation or addition of an aversive stimulus; also called positive punishment

• Punishment by removal: a situation in which an operant is followed by the removal or subtraction of a reinforcing stimulus; also called negative punishment

• Must be applied immediately • Does not teach or promote

alternative, acceptable behavior

• May produce undesirable results such as hostility, passivity, fear

• Results likely to be temporary• May model aggression

Problems with Punishment

Click here

Strategy 1: Reinforce an incompatible behaviorStrategy 2: Stop reinforcing the problem behaviorStrategy 3: Reinforce the nonoccurrence of the problem behaviorStrategy 4: Remove the opportunity to obtain positive reinforcement

Alternatives to

PunishmentClick here

Shaping

Extinction

Operant Conditioning Terms

Discriminative Stimuli

Schedules of Reinforcemen

t

Discriminative Stimuli – Components of Operant ConditioningDiscriminative stimulus: Specific stimulus in the presence of which a particular operant is more likely to be reinforced

Discriminative Stimuli Click here

• Operant conditioning procedure of selectively reinforcing successively closer approximations of a goal behavior until goal behavior is displayedExample: training an animal to perform a complex trick

• Skinner believed that shaping could explain how people acquire a wide variety of abilities and skills

ShapingClick here

Extinction (in operant conditioning)• Gradual weakening and disappearance of

conditioned behavior • In operant conditioning, extinction occurs when an

emitted behavior is no longer followed by a reinforcer

ExtinctionClick here

The Partial Reinforcement Effect and Schedules of Reinforcement

• Early work by Skinner used continuous reinforcement: a schedule of reinforcement in which every occurrence of a particular response is reinforced.

• Running out of food for his rats – Skinner stretched out the pellets by not rewarding every trial and discovered the partial reinforcement effect.• Partial reinforcement effect: Behaviors that are

conditioned using partial reinforcement are more resistant to extinction than behaviors that are conditioned using continuous reinforcement.

The Schedules of Reinforcement

Skinner (1956) found that specific preset arrangements of partial reinforcement produced different patterns and rates of responding and delaying of extinction.

Ratio schedules are based on number of responses emitted

• Fixed ratio (FR)—a reinforcer is delivered after a certain (fixed) number of correct responses.

• Variable ratio (VR)—a reinforcer is delivered after an average number of responses, but varies from trial to trial.

Interval schedules are based on time

• Fixed interval (FI)—reinforcer is delivered for the first response after a fixed period has elapsed.

• Variable interval (VI)—reinforcer is delivered for the first response after an average time has elapsed; differs between trials.

Behavior modification

Application of learning principles to help

people develop more effective or adaptive

behavior

Applications of Operant

Conditioning

Click here

Business – increasing productivity

Clinical Psychology – dealing with

counterproductive behaviors

Sports Training – aiding

performance

Education and Working with Students –

improving grades and study habits

Today psychologists

acknowledge the importance of

Cognitive factors

Contemporary Views of Operant ConditioningCognitive Aspects of Operant Conditioning

Evolutionary factors

Cognitive Factors – Tolman’s WorkCognitive Maps and Latent LearningDemonstrated that animals learn a cognitive map of a maze instead of a series of responses.• 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.

Tolman believed and

demonstrated that operant conditioning

involves cognitive

representation of the

relationship between a

behavior and its consequence.

Cognitive Aspects Continued

Learned Helplessness (Seligman)• Learned helplessness—

phenomenon in which exposure to inescapable and uncontrollable aversive events produces passive behavior

• The cognitive expectation that behavior would have no effect on the environment causes a person or animal to become passive

• Can be seen in studying behavior, athletic performance, and psychological disorders such as depression management

Operant Conditioning and Biological Predispositions

Skinner and other behaviorists firmly believed that general laws of operant conditioning applied to all animal species.

Others (like Brelands) found that an animal’s natural behavior patterns could influence the learning of new behaviors based on biological and evolutionary predispositions

The principle of instinctive drift (naturally occurring behaviors that interfere with operant responses) prevented the animals from engaging in the learned behaviors that would result in reinforcement

Review of Classical Conditioning Versus Operant Conditioning

Observational Learning

Albert Bandura strongly identified with observational learning

The Bobo Doll Study• Bandura demonstrated the influence of

observational learning in a series of experiments conducted in the early 1960s. Children watching a violent video clip seemed to imitate aggressive behavior.

• Demonstrated the principle that expectation of reinforcement (by watching someone being rewarded) can act to reinforce a behavior.

Learning through watching and imitating the behaviors of others

Giacomo Rizzolatti—The major discovery:• Record from monkey motor cortex cells as monkey

watched a lab assistant pick up a peanut, a neuron fired in the monkey’s brain—the same neuron that fired when monkey itself picked up a peanut.

• Mirror neurons have been found in many brain regions.• MRI and direct recording indicate the existence of mirror

neurons in people.

Mirror Neurons: Imitation in the Brain?

A type of neuron that activates both when an action

is performed and when the same action is perceived

Observational Learning in Animals

Demonstrated in• Puppies learning how to detect

drugs from German shepherd mothers

• Hamsters, crows, lemurs, guppies• Rats learn food preferences from

others• Chimps and apes• Macaques learn how to order photos

through observing others

Applications of Observational Learning Adolescents may engage in

sexual behavior earlier if they watch shows with sexual contact.

Adolescents who view pornographic sites may have more sexual partners and engage in substance abuse.

TV shows about literacy in Mexico increased enrollment in literacy groups.

Does media violence promote violence? Some studies and major

medical and psychological organizations say it does.

Other researchers argue the data is correlational and lab research does not address the complex causes of violence in society.

Do you remember the difference

between correlation and causality?