Intro Lecture 6 Learning

7/29/2019 Intro Lecture 6 Learning

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Learning


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Learning

B. F. Skinner, who was inspired by the work of

Watson and Pavlov, has been one of the most

influential people in contemporary psychology

Skinner believed that, to be scientists,

psychologists had to study observable actions

and focus on the behaviors people and

nonhuman animals display


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What Ideas Guidethe Study of Learning?

Define classical conditioning.

Differentiate between US, UR, CS, and CR.

Describe the role of learning in thedevelopment and treatment of phobias anddrug addiction.

Discuss the evolutionary significance of

classical conditioning.


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What Ideas Guidethe Study of Learning?

Skinnerand other behaviorists dismissed the

importance of introspection and mental states

in favor of basic learning principles and

scientific approaches to psychology.

Learning theories have been used to improve

quality of life and to train humans and

nonhuman animals to learn new tasks.


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Learning Results from Experience

Learning: a relatively enduring change in behavior,resulting from experience

Associations develop through conditioning, a

process in which environmental stimuli and

behavioral responses become connected

classical (Pavlovian) conditioning: learning that

two types of events occur together

operant (instrumental) conditioning: learning that

a behavior leads to a particular outcome


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Learning Results from Experience

Learning Theory arose in the early twentieth centuryin response to Freudian and introspectiveapproaches

John B. Watson argued that only observable behaviorwas a valid indicator of psychological activity, andthat the infant mind was a tabula rasa, or blank slate

He stated that the environment and its effects werethe sole determinants of learning

Behaviorism was the dominant paradigm into the1960s, and had a huge influence on every area ofpsychology


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Behavioral Responses Are Conditioned

Watson was influenced by Ivan Pavlovs research onthe salivary reflex, an automatic response when foodstimulus is presented to a hungry animal

Pavlov noticed the dogs salivated as soon as theysaw the bowls that usually contained food,suggesting a learned response


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Pavlovs Experiments

Classical (Pavlovian) conditioning: A neutral objectcomes to elicit a response when it is associated witha stimulus that already produces that response

A typical Pavlovian experiment involves: Conditioning trials: neutral stimulus AND unconditioned

stimulus are paired to produce reflex, e.g. salivation

Neutral stimulus : anything the animal can see or hear as long as itis NOT associated with the reflex being tested, e.g. ringing bell

Unconditioned stimulus (US): a stimulus that elicits a response,such as a reflex, without any prior learning, e.g. food

Critical trials: neutral stimulus alone is tested, and effecton the reflex is measured


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Terminology of Pavlovs Experiments

Unconditioned response (UR): a response that does not haveto be learned, such as a reflex

Unconditioned stimulus (US): a stimulus that elicits aresponse, such as a reflex, without any prior learning

Conditioned stimulus (CS):a stimulus that elicits a responseonly after learning has taken place

Conditioned response (CR): a response to a conditionedstimulus; a response that has been learned


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Acquisition, Extinction, andSpontaneous Recovery

Pavlov was influenced by Darwin and believed thatconditioning is the basis of adaptive behaviors

Acquisition : the gradual formation of an association

between the CS and US

The critical element in the acquisition of a learnedassociation is time, or contiguity

The CR is stronger when there is a very brief delaybetween the CS and the US

For example, scary music begins to play right before afrightening scene in a movienot during or after


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Acquisition, Extinction, andSpontaneous Recovery

How long do learned behaviors persist?

Animals must learn when associations are no longeradaptive

extinction : a form of learning that the prior association nolonger holds. The CR is weakened when the CS is repeatedwithout the US, and eventually extinguishes

Spontaneous recovery: a previously extinguishedresponse reemerges after the presentation of the CS

The recovery will fade unless the CS is again pairedwith the US

Extinction inhibits the associative bond, but does noteliminate it


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Phobias and Addictions HaveLearned Components

Classical conditioning helps explain many

behavioral phenomena. Among the examples

are phobias and addictions.


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Phobias and Their Treatment

phobia: an acquired fear out of proportion to

the real threat of an object or of a situation

Fear conditioning: the process of classically

conditioning animals to fear neutral objects

The responses include specific physiological

and behavioral reactionsfreezing: may be a hardwired response to fear that

helps animals deal with predators


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Phobias and their Treatment

In 1919, John B. Watson became one of the firstresearchers to demonstrate the role of classicalconditioning in the development of phobias bydevising the Little Albert experiment

At the time, the prominent theory of phobias wasbased on Freudian ideas about unconsciousrepressed sexual desires

Watson proposed that phobias could be explained bysimple learning principles, such as classicalconditioning


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The Little Albert Research Method:

Little Albert was presented with neutral objects (a whiterat and costume masks) that provoked a neutral response

During conditioning trials, when Albert reached for thewhite rat (CS) a loud clanging sound(US) scared him (UR)

Results: Eventually, the pairing of the rat CS and theclanging sound (US) led to the rats producing fear (CR) onits own. The fear response generalized to other stimuli

presented with the rat initially, such as the costume masks

Conclusion: Classical conditioning can cause people to fearneutral objects


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Watson planned to conduct extinction trials to

remove the learned phobias but Alberts mother

removed him from the study

Do you think this type of research is ethical?

Watsons colleague, Mary Cover Jones, used classic

conditioning techniques to develop effective

behavioral therapies to treat phobias Counterconditioningexposing a patient to small doses of

the feared stimulus while they engage in an enjoyable task


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systematic desensitization: a formal treatment

based on counterconditioning

Developed by behavioral therapist Joseph Wolpe

in 1997

CS CR1 (fear) connection can be broken by

developing a CS CR2 (relaxation) connection

Psychologists now believe that exposure to

the feared stimulus is more important than

relaxation


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Drug Addiction

Classical conditioning also plays an important role indrug addiction.

Environmental cues associated with drug use caninduce conditioned cravings

Unsatisfied cravings may result in withdrawal, anunpleasant state of tension and anxiety, coupled withchanges in heart rate and blood pressure

The sight of drug cues leads to activation of theprefrontal cortex and various regions of the limbicsystem and produces an expectation that the drughigh will follow


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Drug Addiction

Psychologist Shepard Siegel (2005) believed exposing addictsto drug cues was an important part of treating addiction

Exposure helps extinguish responses to the cues and prevents themfrom triggering cravings

Siegel and his colleagues conducted research into therelationship between drug tolerance and situation

The body has learned to expect the drug in that location andcompensates by altering neurochemistry or physiology to metabolizeit

Conversely, if addicts take their usual large doses in novel settings,they are more likely to overdose because their bodies will not respondsufficiently to compensate


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Classical ConditioningInvolves More Than Events

Occurring at the Same Time

Pavlovs original explanation for classical conditioning wasthat any two events presented in contiguity would produce a

learned association

Pavlov and his followers believed that the associationsstrength was determined by factors such as the intensity ofthe conditioned and unconditioned stimuli

However, in the mid-1960s, a number of challenges toPavlovs theory suggested that some conditioned stimuli weremore likely than others to produce learning

Contiguity was not sufficient to create CS-US associations


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Evolutionary Significance

Psychologist John Garcia and colleagues showed that certainpairings of stimuli are more likely to become associated thanothers

_____________ _____________: the association between

eating a food and getting sick Response occurs even if the illness was caused by a virus or some

other condition

Especially likely to occur if the food was not part of the persons usualdiet. A food aversion can be formed in one trial

Animals that associate a certain flavor with illness, andtherefore avoid that flavor, are more likely to survive and passalong their genes


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Evolutionary Significance

Learned adaptive responses may reflect the survivalvalue that different auditory and visual stimuli havebased on potential dangers associated with thestimuli

What evolutionary value do you see in this learnedbehavior?

_____________ _________: Psychologist MartinSeligman (1970) argued that animals are genetically

programmed to fear specific objects People are predisposed to wariness of outgroup

members (Olsson, Ebert, Banaji, & Phelps, 2005)


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How Does Operant ConditioningDiffer from Classical Conditioning?

Define operant conditioning.

Distinguish between positive reinforcement,

negative reinforcement, positive punishment,

and negative punishment.

Distinguish between schedules of

reinforcement.

Identify biological and cognitive factors that

influence operant conditioning.


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How Does Operant ConditioningDiffer from Classical Conditioning?

_____________ _____________: a learning process in which

the consequences of an action determine the likelihood that it

will be performed in the future

B. F. Skinner chose the term operantto express the idea that

animals operate on their environments to produce effects.

_____________ _____ performed the first reported carefully

controlled experiments in comparative animal psychology

using apuzzle box.

_____________ ___: Any behavior that leads to a satisfying state of

affairs is likely to occur again, and any behavior that leads to an

annoying state of affairs is less likely to occur again.


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Reinforcement Increases Behavior

Thirty years after Thorndike, Skinner developed a

more formal learning theory based on the law of

effect

He objected to the subjective aspects of Thorndikeslaw of effect: States of satisfaction are not

observable empirically

Skinner believed that behavior occurs because it hasbeen reinforced

_____________ : a stimulus that follows a response and

increases the likelihood that the response will be repeated


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The Skinner Box

An operant chamber that allowed repeated

conditioning trials without requiring

interaction from the experimenter

Contained one lever connected to a food

supply and another connected to a water

supply


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Shaping

Sometimes animals take a long time to perform the

precise desired action. What can be done?

_____________ : an operant-conditioning technique

that consists of reinforcing behaviors that areincreasingly similar to the desired behavior

_____________ _________: any behavior that even

slightly resembles the desired behavior

Suppose you wanted to teach yourself to do

something. Which behavior would you choose, and

how would you go about shaping it?


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Reinforcers Can Be Conditioned

________________: satisfy biological needs

such as food or water

_____________ _____: events or objects

established through classical conditioning that

serve as reinforcers but do not satisfy

biological needs, e.g. money or compliments


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Both Reinforcement and PunishmentCan Be Positive or Negative

Reinforcement and punishment have the opposite

effects on behavior

Both reinforcement and punishment can be positive

or negative

This designation depends on whether something isgiven or removed, not on whether any part of the

process is good or bad


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Positive and Negative Reinforcement

Reinforcement positive or negative

increases the likelihood of a behavior

_____________ ______: the administration of a

stimulus to increase the probability of a behaviors

being repeated, e.g. a reward

_____________ ______: the removalof a stimulus

to increase the probability of a behaviors beingrepeated, e.g. requiring a rat to press a lever to

turn off a shock


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Positive and Negative Punishment

Punishment reduces the probability that abehavior will recur

_____________ _______: the administration of a

stimulus to decrease the probability of abehaviors recurring, e.g. receiving a ticket forspeeding

_____________ _______: the removal of a

stimulus to decrease the probability of abehaviors recurring, e.g. taking away drivingprivileges for bad behavior


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Effectiveness of Parental Punishment

For punishment to be effective, it must be reasonable,

unpleasant, and applied immediately so that the relationship

between the unwanted behavior and the punishment is clear

How might this go wrong?

Punishment often fails to offset the reinforcing aspects of the

undesired behavior

Research indicates that physical punishment is often

ineffective, compared with grounding and time-outs Many psychologists believe that positive reinforcement is the

most effective way of increasing desired behaviors while

encouraging positive parent/child bonding


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Operant Conditioning is Influenced bySchedules of Reinforcement

How often should reinforcers be given?

continuous reinforcement: a type of learning

in which behavior is reinforced each time it

occurs

partial reinforcement: a type of learning

inwhich behavior is reinforced intermittently

Partial reinforcements effect on conditioning

depends on the reinforcement schedule


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Ratio and Interval Schedules

Partial reinforcement can be administered

according to either the number of behavioral

responses or the passage of time

ratio schedule: Reinforcement is based on the

number of times the behavior occurs

interval schedule: Reinforcement is provided after

a specific unit of time

Ratio reinforcement generally leads to greater

responding than does interval reinforcement


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Fixed and Variable Schedules

Partial reinforcement can also be given on a

fixed schedule or a variable schedule

fixed schedule: Reinforcement is provided after a

specific number of occurrences or after a specific

amount of time

variable schedule: Reinforcement is provided at

different rates or at different times


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Behavior Modification

_____________ _________: the use ofoperant-conditioning techniques to eliminateunwanted behaviors and replace them with

desirable ones _____________ ______ operate on the

principle of secondary reinforcement. Tokensare earned for completing tasks and lost forbad behavior. Tokens can later be traded forobjects or privileges


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Biology and Cognition InfluenceOperant Conditioning

Behaviorists such as Skinner believed that all

behavior could be explained by

straightforward conditioning principles

However, a great deal about behavior remains

unexplained

Biology constrains learning, and reinforcement

does not always have to be present for

learning to take place


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Acquisition/Performance Distinction

Tolman argued that learning can take place withoutreinforcement

latent learning: takes place in the absence of reinforcement

insight learning: A solution suddenly emerges after either a period of

inaction or of contemplation

Tolmans studies involved rats running through mazes

cognitive map: a visual/spatial mental representation of anenvironment

The presence of reinforcement does not adequately explaininsight learning, but it helps determine whether the behavioris subsequently repeated


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Does Watching OthersAffect Learning?

Describe the concept of the meme.

Define observational learning.

Generate examples of observational learning,modeling, and vicarious learning.

Discuss contemporary evidence regarding the

role of mirror neurons in learning.


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Does Watching OthersAffect Learning?

Teaching someone to perform a complex task

requires more than reinforcing arbitrary

correct behaviors.

We learn many behaviors, including attitudes,

through observation.


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Learning Can Be Passed Onthrough Cultural Transmission

_____________ : a unit of knowledge

transmitted within a culture

Can be conditioned through association or

reinforcement, but are often learned by

watching the behavior of other people

Through social learning, some behaviors are

passed along from one generation to the next


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Learning Can Occurthrough Observation and Imitation

_____________ ______: the acquisition or

modification of a behavior after exposure to at

least one performance of that behavior

Observational learning is a powerful adaptive

tool for humans and other animals


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Banduras Observational Studies

Banduras studies suggest that exposing

children to violence may encourage them to

act aggressively


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Media and Violence

The extent to which media violence impactsaggressive behavior in children is debated

Some studies demonstrate desensitization to

violence after exposure to violent video games However, it is difficult to draw the line between

playful and aggressive behaviors in children

There may be extraneous variables that affect both

TV habits AND violent tendencies


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Social Learning of Fear

Susan Mineka noticed that lab-reared

monkeys were not afraid of snakes the way

monkeys in the wild are

Her research demonstrated that animals fears

can be learned through observation


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Demonstration and Imitation

modeling: the imitation of behavior throughobservational learning

Modeling is effective only if the observer is

physically capable of imitating the behavior Imitation is much less common in nonhuman

animals than in humans

Adolescents who associate smoking withadmirable figures are more likely to beginsmoking

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Intro Lecture 6 Learning