Learning

Chapter 6

Learning

• Learning – A process through which experience produces lasting change in behavior or mental processes– “Lasting change”- You go to the Doctor’s

office and get an unpleasant injection, during which the sight of the needle becomes associated with pain. As a result, the next time you need a shot, you wince when you spot the needle.

Behavioral Learning

Behavioral learning – Forms of learning that can be described in terms of stimuli and responses

-Classical and Operant conditioning• Behaviorist have disagreed with Cognitive

psychologist for years.– Behaviorist believe that we should ignore

“mental processes” while cognitive psychologist argue that understanding learning requires in-depth mental processes.

Learning vs. Instincts

• Nearly every human activity involves some type of learning…(working, interacting with friends and families)

• Without learning, we would be forced to rely on simple reflexes and innate behaviors or instincts.– Why could this be harmful?

• Learning represents an evolutionary advance over instincts.

Simple Forms of Learning

• Habituation – Learning not to respond to repeated presentation of a stimulus.– If you live on a busy street, you learn to ignore

the sounds of traffic and commotion. – This type of learning occurs in all animals that

have nervous systems, including insects and worms.

Simple Forms of Learning

• Mere exposure effect – Learned preference for stimuli to which we have been previously exposed– This type of learning is seen most commonly

in humans.– Example: effectiveness of advertisements or

commercials

What sort of learning does Classical Conditioning Explain?

• Core Concept:– Classical conditioning is a basic form of

learning in which a stimulus that produces an innate reflex becomes associated with a previously neutral stimulus, which then acquires the power to elicit essentially the same response.

– http://videosift.com/video/The-Office-Dwight-taste-bud-prank-wAltoids

Classical Conditioning

• Ivan Pavlov-– Set up an experiment to see if untrained dogs could

begin salivating even before food was put in their mouths.

• His experiment:– He first placed an untrained dog in a harness. At

intervals a tone was sounded and the dog was given a bit of food. Gradually, the dog began to salivate in response to the tone alone (neural stimulus)

– The dog began to connect the tone to food.

Classic Conditioning Terms

• Neutral stimulus – Any stimulus that produces no conditioned response prior to learning

• Acquisition – Initial learning stage in classical conditioning; a neutral stimulus (tone) is paired with the unconditioned stimulus.

Essentials of Classical Conditioning

• Unconditional Stimulus (UCS)• Unconditioned Response (UCR)• Conditioned Stimulus (CS)• Conditioned Response (CR)

Unconditioned Stimulus

• A stimulus that automatically—that is without conditioning—provokes a reflexive, unconditioned, response.

• In Pavlov’s experiments, food was used as the UCS because it produced a salivation reflex.

• UCS-UCR involves NO LEARNING

Unconditioned Response(UCR)

• The response elicited by an unconditioned stimulus without prior learning.

• What is UCR in Pavlov's experiment?

Conditioned Stimulus (CS)

• A previously neutral stimulus that comes to elicit the conditioned response.– In Pavlov’s experiment the tone produced

salvation was formerly a neutral stimulus but has become a conditioned stimulus.

Conditioned Response (CR)

• A response elicited by a previously neutral stimulus that has become associated with the unconditioned stimulus.

• What is the CR in Pavlov’s experiment?

Classical Conditioning

• Prior to conditioning: Image

Classical Conditioning(More Terms)

• Extinction – Weakening of a conditioned association in the absence of an unconditioned stimulus or reinforcer.– Occurs when a CR is eliminated by repeated

presentations of the CS without the UCS– Pavlov: Conditioned salivation responses in

Pavlov’s dogs were easily eliminated by withholding the UCS (food) over several trials in which the CS (tone) was presented alone.

Classical Conditioning(More Terms)

• Spontaneous recovery –Reappearance of an extinguished conditioned response after a time delay– Occurs when the conditioned response nearly

always reappears at a lower intensity.– Important in behavior modification therapy for

fears.

Classical Conditioning:Generalization and Discrimination

• Stimulus generalization involves giving a conditioned response to stimuli that are similar to the CS.

• Pavlov demonstrated this by showing that a well-trained dog would salivate in response to a bell that made a slightly different sound from the one he had used during conditioning.– This is evident is everyday life fears—If you fear

spiders, you will probably respond the same way to all spiders regardless of their size or color.

Classical Conditioning:Generalization and Discrimination

• Stimulus discrimination involves responding to one stimulus but not to stimuli that are similar.

• Pavlov and his students demonstrated this when they taught the dogs to distinguish btw two tones of different frequencies. One tone was followed by food, the other wasn’t. Eventually the dogs learned to discriminate the tones.– In everyday life this is seen in our preference for one

commercial brand over another, ex- Pepsi vs. Coke

Experimental Neurosis

• A pattern of erratic behavior resulting from confusing stimuli.

• People who become irritable and defensive when they have difficult choices to make, their behavior pattern becomes known as “experimental neurosis”.

• http://www.youtube.com/watch?v=hhqumfpxuzI

Pavlov’s Experiment

Applications of Classical Conditioning

• “Little Albert”- experiment done by John B. Watson and Rosalie Rayner over 80 years ago.

• This experiment would be unethical if done today.

• They conditioned an infant (Albert) to react fearfully to a white lab rat.

Little Albert

• They created this fear by repeatedly presenting the rat with a loud sound (UCS).– It only took 7 trials for “Little Albert” to react

with fear to the appearance of the rat (CS) alone.

– His fear faded quickly, so they found it necessary to strengthen his response periodically.

– http://www.youtube.com/watch?v=FMnhyGozLyE

Application of Classical Conditioning

• Taste-aversion learning – Biological tendency in which an organism learns to avoid food with a certain taste after a single experience, if eating it is followed by illness

A Challenge to Pavlov

• Why are some stimuli-consequence combinations readily learned while other combinations are highly resistant to learning?

• What any organism can or cannot learn in a given setting is due in part to its evolutionary history.

How do we learn new behaviors by Operant Conditioning?

• Core Concept:– In operant conditioning, the consequences of

behavior, such as rewards and punishments, influence the chance that our behavior will occur again.

• http://www.youtube.com/watch?v=qy_mIEnnlF4&feature=player_detailpage

How do we learn new behaviors by Operant Conditioning?

• Law of Effect- – The idea that responses that produce

desirable results would be learned. (B.F. Skinner).

• B.F. Skinner believed that the most powerful influences on behavior are its consequences

How do we learn new behaviors by Operant Conditioning?

• Trial-and-error learning – Learner gradually discovers the correct response by attempting many behaviors and noting which ones produce the desired consequences

The Power of Reinforcement

• Reinforcer- the term Skinner used instead of reward. Meaning that any condition that follows and strengthens a response.

• There are two types:– 1. Positive Reinforcement– 2. Negative Reinforcement

Positive/Negative Reinforcement

• The word “negative” is used in the mathematical sense of subtract or remove, while “positive” means add or apply.– Ex- Using an umbrella to avoid getting wet

during a down pour is a behavioral learned and maintained by negative reinforcement. That is, you use the umbrella to avoid an unpleasant stimulus (getting wet)

Positive Reinforcement

• Positive Reinforcement- Stimulus presented after a response that increases the probability of that response happening again.

• Give some examples!

Negative Reinforcement

• Removal of an unpleasant stimulus, contingent on a particular behavior.

– Ex- buckling your seat belt to turn of the annoying beeping sound.

Contingencies of Reinforcement

• Continuous reinforcement – Reinforcement schedule in which all correct responses are reinforced.– It is a useful tactic in the early learning process,

because rewarding every correct response gives feedback on how well each response was performed.

– Its useful for shaping complex behaviors, such as playing musical instrument.

– Could be said to be the best strategy for teaching and learning new behaviors.

Contingencies of Reinforcement

• Intermittent Reinforcement or partial reinforcement- it’s the rewarding of some, but not all correct response from an incorrect one.– Intermittent Reinforcement is the most efficient way

to maintain behaviors that have already been learned.

– A big advantage of this type of reinforcement comes from the resistance to extinction that it produces.

• Gamblers- pg. 209

Schedules of Reinforcement

• Two types:– 1. Ratio Schedule– 2. Interval Schedule

Ratio Schedule

• Ratio schedules – Provide reward after a certain number of responses– You pay your employees based on the

amount of work they do.

• Ratio Schedules is broken down into 2 variables– 1. Fixed Ratio– 2. Variable Ratio

Fixed Ratio (FR)

• Programs by which reinforcement is contingent on a certain, unvarying number of responses.– The amount of work (the number of

responses) needed for a reward remains constant.

– Ex- Workers are paid on piecework basis. You pay each worker a dollar for every 10 tires produced.

Variable Ratio

• These schedules are less predictable. These are reinforcement programs by which the number of responses required for a reinforcement varies from trial to trial.– Ex- telemarketers work on a VR schedule.

They never know how many phone calls they must make make before they get the next sale.

Interval Schedules

• Reinforcement is based on the responses made within a certain time period (instead of on the number of responses given).

• Divided into two schedules:– 1. Fixed Interval Schedules (FI)– 2. Variable Interval Schedules (VI)

Fixed Interval Schedules

• Programs by which reinforcement is contingent on a certain, fixed time period.

• Common in the work world, where they map appear as a monthly paycheck.

• Usually has a low response rate

Variable Interval Schedules

• Most unpredictable of all. Time interval btw rewards varies. – Example: Fishing- you might fish for hours

with no bites, but then finally you catch a huge fish!

The Power of Reinforcements

• Primary reinforcements- They have a innate basis because of their biological value to the organisms. – Ex- food, water, shelter

The Power of Reinforcements

• Secondary Reinforcements-– Stimuli, such as money or tokens, that acquire

their reinforcing power by their learned association with primary reinforcer (also called conditioned reinforcer)

Premack Principle

• Concept developed by David Premack, that a more preferred activity can be used to reinforce a less preferred activity.

• Getting people to partake in a less preferred activity before they can do something they like.– Ex- doing chores before playing with your

friends.

The Problem of Punishment

• Punishment- An aversive(acts of an opposite of reinforcement) stimulus which diminishes the strength of the response it follows.

• Punishment comes in two forms:– 1. Positive Punishment– 2. Omission Training or Negative Punishment

Positive Punishment

• The application of an aversive stimulus after a response.– Ex when you touch a hot plate, the painful

consequence reduces the likelihood of you repeating that behavior.

Omission Training

• The removal of an appetitive stimulus after a response

• Or the removal of a reinforcer– Ex- Parents take away a misbehaving teen’s

car keys.

Punishment

• Unlike reinforcement, punishment must be administered consistently to be effective.– Intermittent Punishment is far less effective

than punishment delivered AFTER a undesired response.

– Not punishing an occurrence of unwanted behavior can have the effect of rewarding it.

Punishment vs. Negative Reinforcement

• Both involve unpleasant stimuli, but they differ.– Punishment is used to decrease a behavior or

reduce its probability of recurring.– Negative Reinforcement always increases a

response’s probability of occurring again.

Four Kinds of Punishment

The Uses and Abuses of Punishment

• Power usually disappears when threat of punishment is removed

• Punishment• Often triggers aggression• May inhibit learning new and better responses• Is often applied unequally

When does punishment work?

• In limited circumstances, punishment works remarkably well.

• Punishment should meet certain conditions.

Punishment Conditions

• Punishment should be swift- “you’ll get spanked when your Father gets home”.

• Punishment should be certain- consistently administered every time the unwanted response occurs.

• Punishment should be limited in duration and intensity- just enough to stop the behavior but appropriate enough to “make the punishment fit the crime”.

Conditions of Punishment

• Punishment should clearly target the behavior, not the character of the person.

• Punishment should be limited to the situation in which the response occurred.

• Punishment should not give mixed messages.

• *The most effective punishment is normally omission, taking away privileges.

Compared Conditioning

• Chart on 215• Classical conditioning involves the

association of two stimuli (UCS + CS) before the response or behavior

• Operant conditioning involves a reinforcing (reward) or punishing stimulus after a response or behavior

How does Cognitive Psychology Explain Learning?

• According to cognitive psychology, some forms of learning must be explained as changes in mental processes, rather than as changes in behavior alone.

How does Cognitive Psychology Explain Learning?

• Insight learning – Problem solving occurs by means of a sudden reorganization of perceptions

• Cognitive maps –A mental representation of physical space

Observational Learning

• Albert Bandura: suggested that observing violent behavior(at least in children) makes viewers more likely to behave violently.

• BoBo Doll Experiment:• http://www.youtube.com/watch?v=zerCK0l

Rjp8– Findings:– Significance:

How does Cognitive Psychology Explain Learning?

• Observational learning – Form of cognitive learning in which new responses are acquired after watching others’ behavior and the consequences of their behavior.

• Examples:

Brain Mechanisms in Learning

• Long-term potentiation – Biological process involving physical changes that strengthen the synapses in groups of nerve cells; believed to be the neural basis of learning.

• Use your book: What neurotransmitters are released? What brain systems?

Higher “Cognitive” Learning

• What have psychologist found: