Mary Jones. In This Chapter Learning Through Classical ConditioningLearning Through Operant...

Mar

y Jo

nes

In This Chapter

Learning Through Classical Conditioning

Learning Through Operant Conditioning

Biological and Cognitive Aspects of Learning


The Elements and Procedures of Classical Conditioning

General Learning Processes in Classical Conditioning

Different Foci

Behavioral psychologists

• Focus on the learning of associations through classical conditioning and operant conditioning

Cognitive psychologists

• Are interested in the more complex type of learning involved in human memory


• Classical conditioning- Process of learning in which one stimulus signals

the arrival of another stimulus- Sometimes called “Pavlovian” conditioning- Ivan Pavlov was the first researcher to

systematically study this type of learning

Pavlov's Dog Study

Studying initial step in the digestive process• Dogs were strapped into

harnesses and had tubes inserted into their cheeks

• Amount of salivation was measured

• With time, the dogs started to salivate before the meat powder was even put in their mouths

This is a photograph of Pavlov's experimental laboratory.

The Elements and Proceduresof Classical Conditioning

• Neutral stimulus- Stimulus that does not naturally elicit the to-be-

conditioned response (e.g., auditory tones)

• Unconditioned stimulus (UCS)- Stimulus in a reflex that automatically elicits an

unconditioned response

• Unconditioned response (UCR) - Response in a reflex that is automatically elicited by

the unconditioned stimulus

The Elements and Procedures of Classical Conditioning

• Conditioned stimulus (CS)- Stimulus that comes to elicit a new response (the

conditioned response) in classical conditioning

• Conditioned response (CR) - Response that is elicited by the conditioned

stimulus in classical conditioning

Elements and Procedures of Classical Conditioning

Unconditioned Stimulus

(UCS)

Unconditioned Response

(UCR)

Conditioned Stimulus

(CS)

Conditioned Response

(CR)

Associated Similar

CS and CR

• To achieve conditioning, a tone (neutral stimulus) is presented just before the meat powder (USC) for several trials.

• Once the dog starts to salivate to the sound of the tone (conditioning) before the food is put in its mouth, the tone is now called the conditioned stimulus (CS).

• The learned response to the conditioned stimulus is called the conditioned response (CR).

Delayed and Trace Conditioning

• Delayed conditioning- Offset of the CS is delayed until after the UCS is presented so that the

two stimuli occur at the same time- Tone would be turned on and continue to sound until the meat powder

was placed in the dog's mouth- Delayed conditioning is the most effective procedure for classical

conditioning

• Trace conditioning- Period of time between the offset of the CS and the onset of the UCS

when neither stimulus is present- It is called “trace” conditioning because there must be a memory trace

of the CS for the association between stimuli to be learned- Trace conditioning can be effective provided the interval between stimuli

is brief

A Classical Conditioning Experiment

The Elements of Classical Conditioning

The “Little Albert” Study

John Watson and Rosalie Rayner conducted a

study on an 11-month-old infant named Albert

While Albert was looking at a little white rat, Watson quietly sneaked behind him with a long iron bar and a hammer

and clanged the two together

Albert's reflexive response, the UCR, was a fear-

avoidance response to the loud noise, which was the

UCS

After pairing the white rat with the unexpected loud

noise only 7 times, the white rat became a ______?

Fear and Positive Emotions

• Deconditioned a preexisting fear of rabbits in a 3-year-old boy

Mary Cover Jones • Unable to condition

infants to fear inanimate objects such as wooden blocks and cloth curtains

• Concluded possible biological predispositions to learn certain fears more easily than others

Elsie Bregman: Fear study

Fear and Positive Emotions

• Positive emotions- Classical conditioning can be used in advertising

to condition positive attitudes and feelings toward certain products

Do you have a favorite beverage? Have you ever seen or heard it advertised in the media?


• Acquisition- Process of acquiring a new response, that is, a

CR to a CS- Strength of the CR increases during acquisition


• Other Processes- Extinction- Spontaneous recovery- Stimulus generalization- Stimulus discrimination

Let's look at each of these more closely.

Extinction

Extinction

Disappearance of the CR when the UCS no longer follows the CSCS must reliably signal that the UCS is comingStrength of the CR decreases during extinction

Spontaneous Recovery

Spontaneous recovery

Acquisition, Extinction, and Spontaneous Recovery

Stimulus Generalization and Stimulus Discrimination

• Stimulus generalization- Elicitation of the CR to

a stimulus similar to the CS

- The more similar the stimulus is to the CS, the stronger the response will be

• Stimulus discrimination- Learning to give the

CR only to the CS or only to a small set of very similar stimuli, including the CS

- Overgeneralizing a response may not be adaptive; people need to learn to discriminate among stimuli

Discrimination Training

• Discrimination training- Person presented many different stimuli

numerous times- UCS only follows one CS- Procedure will extinguish the responses to other

stimuli

Stimulus Generalization and Discrimination

Learning Through Operant ConditioningLearning Through Reinforcement and Punishment

General Learning Processes in Operant Conditioning

Partial-Reinforcement Schedules in Operant Conditioning

Motivation, Behavior, and Reinforcement

Operant Conditioning

Learning to associate behaviors with their consequences• Behaviors that are reinforced (lead to

satisfying consequences) will be strengthened

• Behaviors that are punished (lead to unsatisfying consequences) will be weakened

The Law of Effect

•Any behavior that results in satisfying consequences tends to be repeated

•Any behavior that results in unsatisfying consequences tends not be repeated

Thorndike's Law of Effect

Thorndyke's Puzzle Boxes

• Edward Thorndike used puzzle boxes in his classic learning studies with cats. The boxes varied in how difficult they were for the cats to escape from.

• The results of these puzzle box experiments led Thorndike to develop the law of effect. Sci

ence

Sou

rce

Learning Through Reinforcement and Punishment

Reinforcer

•Stimulus that increases the probability of a prior response

Reinforcement

•Process by which the probability of a response is increased by the presentation of a reinforcer following the response

Learning Through Reinforcement and Punishment

Punisher•Stimulus that decreases the probability of a prior response

Punishment

•Process by which the probability of a response is decreased by the presentation of a punisher following the response

Positive and Negative Reinforcement and Punishment

Positive means that a stimulus is presented• In both positive

reinforcement and positive punishment, a stimulus presented

Negative means that a stimulus is removed• In both negative

reinforcement and negative punishment, a stimulus is removed

Appetitive and Aversive

Appetitive stimulus• Stimulus that an organism

finds pleasing • Example: Food, money

Aversive stimulus• Stimulus that an organism

finds unpleasing • Example: Sickness, social

isolation

Positive and Negative Reinforcement and Punishment

• Positive means that something is presented, and negative means that something is taken away

• Reinforcement means that the behavior is strengthened, and punishment means that the behavior weakened

• In positive reinforcement, and appetitive stimulus is presented, and in positive punishment, an aversive (unpleasant) stimulus is presented

• In negative reinforcement, an aversive stimulus is removed, and in negative punishment, an appetitive stimulus is removed

How do we know?

• In any example of positive or negative reinforcement or punishment- It is critical to realize that we only know if a

stimulus has served as a reinforcer or a punisher and led to reinforcement or punishment

- If the behavior happens again or stops happening

One More…

• Premack Principle- The opportunity to perform a highly frequent

behavior can reinforce a less frequent behavior.

- Reinforcers are viewed as sequence of behaviors rather than stimuli: Behavior that is being reinforced followed by the behavior that is the reinforcer.

Primary and Secondary Reinforcers

• Behavior modification- Application of classical and operant conditioning

principles to eliminate undesirable behavior and teach more desirable behavior

• Token economies


• Primary reinforcer- Innately reinforcing since birth- Example: Food, social contact

• Secondary reinforcer- Not innately reinforcing, but gains reinforcing

properties through learning- Example: Money, good grades


• Reinforcement without awareness (Hefferline and colleagues)- Demonstrated operant conditioning can occur

without person's awareness in task involving miniscule muscular response to harsh noise and soothing music

- Later demonstrated similar finding in decision-making task

General Learning Processes in Operant Conditioning

• Shaping- Occurs when an animal is trained to make a particular

response by reinforcing successively closer approximations to the desired response

- With humans, this might mean reinforcing a child the closer he comes to making his bed correctly each morning

• Cumulative record - Includes record of the total number of responses over time in

an operant conditioning experiment- Is a visual depiction of the rate of responding- What happens as the slope of the line in a cumulative record

gets steeper?

How to Understand a Cumulative Record

• By measuring how responses cumulate over time, a cumulative record shows the rate of responding

• When no responses occur, the record is flat (has no slope)

• As the number of responses increases per unit of time, the cumulative total rises more quickly

• The response rate is reflected in the slope of the record

• The faster the response rate, the steeper the slope of the record

Acquisition, Extinction, and Spontaneous Recovery

Acquisition • Strengthening

of the reinforced operant response

Extinction• Disappearance

of the operant response when it is no longer reinforced

Spontaneous recovery• Temporary

recovery of the operant response following a break during extinction training

Cumulative Record Illustrations of Acquisition, Extinction, and Spontaneous Recovery

Discrimination and Generalization

• Discriminative stimulus- Stimulus that has to be present for the operant

response to be reinforced- “Sets the occasion” for the response to be

reinforced

• Stimulus generalization- Giving the operant response in the presence of

stimuli similar to the discriminative stimulus


• Continuous schedule of reinforcement- Reinforcing every response

• Partial schedules of reinforcement- Reinforcing behavior only part of the time


• Continuous schedule of reinforcement- Reinforcing the desired operant response each time it is

made

• Partial schedule of reinforcement- Reinforcing the desired operant response only part of the

time

• Partial-reinforcement effect- The finding that operant responses that are reinforced on

partial schedules are more resistant to extinction than those reinforced on a continuous schedule


• Fixed-ratio schedule- Partial schedule of reinforcement in which a

reinforcer is delivered each time a fixed number of responses is made. The fixed number can be any number greater than one.

• Variable-ratio schedule- Partial schedule of reinforcement in which the

number of responses it takes to obtain a reinforcer varies on each trial but averages to a set number across trials.

Fixed Ratio and Variable Ratio Schedules of Partial Reinforcement

Interval Schedules

Fixed interval schedule

Variable interval

schedule

Fixed Interval and Variable Interval Schedules of Partial Reinforcement

Which schedule is best?

Ratio schedules lead to higher rates of responding than interval schedules (steeper slopes on the cumulative record)

With respect to extinction, it will take longer to extinguish a response with a partial-reinforcement schedule than a continuous reinforcement

Variable schedules lead to fewer breaks (no responding occurring) after reinforcement than fixed schedules

Motivation, Behavior, and Reinforcement

• Motivation- Set of internal and external factors that energize

behavior and direct it toward goals

Theories of Motivation

•Bodily need (such as hunger) creates a state of bodily tension called drive

•Motivated behavior (seeking food) works to reduce this drive

•This is done by obtaining reinforcement (food) to eliminate this need and return the body to a balanced internal state

Drive-reduction theory


•Proposes that we are “pulled” into action by incentives

•Incentives are external environmental stimuli that do not involve drive reduction

Incentive theory


•Behavior is motivated to maintain an optimal level of arousal, which varies among people

•When below the optimal level, people are motivated to raise arousal to that level

•When over-aroused, people are motivated to lower arousal level to the optimal level

Arousal theory

The Yerkes-Dodson Law

• Increased arousal will aid performance up to a point, after which further arousal impairs performance

Extrinsic vs. Intrinsic Motivation

• Extrinsic motivation - Desire to perform behavior to obtain an external

reinforcement or to avoid an external aversive stimulus

• Intrinsic motivation- Desire to perform a behavior effectively for its

own sake- Reinforcement is provided by the activity itself

The Overjustification Effect

• Lepper, Greene, and Nisbett (1973)- Some children who enjoyed playing with felt-tipped

pens were given prizes, an extrinsic incentive, for playing with the pens

- Other such children were not given prizes for playing with the pens

• Using the overjustification effect, how do you predict each group of children will play with the pens when the prizes are removed a week later?

The Overjustification Effect

• Why does it occur?- The overjustification effect indicates that a

person's cognitive processing influences behavior and that such processing may lessen the effectiveness of extrinsic reinforcers

- However, extrinsic reinforcement is not likely to impact intrinsic motivation if the extrinsic reinforcement is dependent upon doing something well versus just doing it

Biological and Cognitive Aspects of Learning

Biological Preparedness in Learning

Latent Learning and Observational Learning

Biological Preparedness in Learning

True or false?• Our preparedness to learn to fear objects

dangerous to us and to avoid foods and drinks that make us sick has adaptive significance.

Taste Aversion

Garcia and Koelling (1966):

Rat radiation study

After several radiation

treatments, rats entered

experimental cages but did not drink

waterDifferences in water bottles in

experimental and non-experimental

cages created different tasting

waters

Rats learned aversion to to

experimental cage water bottles

Researchers examined two cues

that were both paired with

sickness through radiation: Sweet-tasting water and

normal tasting water with clicking noises and flashing

lightsLet's see what happened next.

Taste Aversion

Rats that drank the sweet-tasting water easily learned the

aversion to the water

Rats that drank normal-tasting water while they

experienced clicking noises and flashing lights

did not do so

Rats just could not learn to pair these environmental

auditory and visual cues that occurred during their drinking

with their later sickness

The pairing did not make any

“biological” sense to the rats

Instinctual Drift

• Instinctual drift- Tendency of an animal to drift back from learned

operant response to an object to an innate, instinctual response

- Involves biologically instinctual responses that sometimes limit or hinder ability to condition other less natural responses

- Suggests organisms will learn certain associations more easily than others

Instinctual Drift

As shown in these photos, pigs are biologically predisposed to root out their food and raccoons are biologically predisposed to wash their food.

Latent Learning and Observational Learning

• Latent learning- Learning that occurs

but is not demonstrated until there is incentive to do so

• Observational learning (modeling)- Learning by observing

others and imitating their behavior

Edward Tolman pioneered latent-learning research with rats.

Arch

ives

of t

he H

istor

y of

Am

eric

an P

sych

olog

y

Latent Learning

Observational Learning

Albert Bandura's pioneering research on modeling: Bobo doll experiment• Children were exposed to an adult who beats, kicks, and

yells at a Bobo doll or to a room with a gentler adult model

• They were later taken to another room with accessible toys, including a Bobo doll

• When exposed to a gentle model, children acted more gently toward the doll than children exposed to the aggressive model

• Children's behavior was guided by the behavior of the model to which they were exposed

Observational Learning

• Bandura's Bobo doll research- In another experiment, an adult was rewarded for

aggressive behavior, punished for aggressive behavior, or received no consequences

- Children who saw the adult get reinforced for aggressive behavior acted more aggressively toward the Bobo doll than those who had seen the model act with no consequences

- Children who had watched the adult get punished were less likely to act aggressively toward the doll than children who had not been exposed to any consequences for acting aggressively toward the doll

Bobo Doll Experiments

These photographs of the children in the Bobo doll experiments imitating the violent behavior of the adult model show the powerful influence of observational learning.

Courtesy Albert Bandura, Stanford University

Media Violence

• Research on violent television and films, video games, and music- Reveals unequivocal evidence that media violence

increases the likelihood of aggressive and violent behavior in both immediate and long-term contexts

• Mirror neurons- Recent research by neuroscientists has led to the

discovery of neuron systems that provide a neural basis for observational learning

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