Chapter 8

LearningJames HendersonRobert ReedShalom AziagueDenise DelagarzaSeth Ewing-Hendrick

Classical Conditioning

Classical conditioning More than 200 years ago, philosophers

such as John Locke and David Hume echoed Aristotle's conclusion from 2000 years earlier. We learn by association

our minds naturally connect events that occur in sequence.

Example: If you associate a sound with a frightening consequence, then your fear may be aroused by the sound itself

Cont.. By linking two events that occur close together, both

the sea snail and the seal exhibit associate learning. Conditioning is the process of learning association In classical conditioning, we learn to associate two

stimuli and thus to anticipate events. We learn that a flash of lightning signals an impending

crack of thunder ,and so we start to brace ourselves when lightning strikes nearby

In operant conditioning, we learn to associate a response (our behavior) and its consequences and thus to repeat acts followed by good results and avoid acts followed by bad results.

Classical conditioning Ivan Pavlov performed experiments that are

considered classical conditioning Another important psychologist that dealt with

classical conditioning was John B. Watson. John’s idea was that psychology should study

how organisms respond to stimuli in their environments. He thought that psychology should be an objective science based on observable behavior which is called behaviorism

Pavlov experiment After studying salivary secretion in dogs ,he knew that when

he put food in a dog’s mouth, the animal would invariably salivate

The repeated behavior could make the dog salivate with the mere sight of the food, the smell of the food or even the person who brought it

Because salivation in response to food in the mouth was unlearned, Pavlov called it an unconditional response (UR).

Food in the mouth automatically, unconditionally triggers a dog’s salivary reflex. Thus Pavlov called the food stimulus and unconditioned stimulus (US).

One translation of Pavlov therefore calls the salivation the conditional reflex. Today we call this learned response the conditional response (CR).

The permissibly irrelevant tone stimulus that now triggered the conditional salivation we call the conditional stimulus (CS).

Acquisition(Initial learning) To understand acquisition of the stimulus –response relationship,

Pavlov and his associates first had to confront the question of timing. Although it’s not likely for conditioning to occur, it could occur when

the CS follow the US. This finding fits the presumption that classical conditioning is biologically adaptive. It helps organisms prepare for good or bad events.

Michael Domjan Showed how the CS signal are important biological event by conditioning the sexual arousal of male Japanese quail

Ex: Just before presenting an approachable female, the researchers turned on a red light, over time ,the red light announced the arrival of the female quail, which caused the male quail to because sexually aroused and copulate with her more quickly when she arrived. Moreover, the quail grew to enjoy the red-light district of the cage. Exposure to the sexually conditioned stimuli also caused them to release more semen and sperm. The quail’s capacity for classical conditioning gives it a reproductive edge.

Extinction and spontaneous recovery According to Pavlov experiment, when

he sounded the tone again and again without presenting food, the dogs salivated less and less. The declining salivation illustrates extinction.

If allowed several hours to elapse before sounding the tone again, the salivation to the tone would reappear spontaneously

Generalization Pavlov and his students noticed that a dog

conditioned to the sound of one tone also responded somewhat to the sound of a different tone never paired with food.

The tendency to respond to stimuli similar to the CS is called generalization

Example: generalization can be adaptive, as when toddlers taught to fear moving cars in the street respond similarly to trucks and motorcycles.

Discrimination Pavlov dogs also learned to respond to

the sound of a particular tone and not to other tones.

Like dog generalization, discrimination has survival value. Slightly different stimuli are at time followed by vastly different consequences

Extending Pavlov’s understanding Pavlov’s and Watson’s Disdain for

“mentalist” concepts such as consciousness has given way to a growing realization that they underestimated the importance of cognitive processes(thoughts, perceptions , expectations)and biological constraints on an organism’s learning capacity

Cognitive processes Robert Rescorla and Allan Wagner argued that when

two significant events occur close together in time, an animal learns the predictability of the second event.

An example of this is if a shock is always precede by a tone, and then sometimes also by a light that accompanies the tone, a rat will react with fear to the tone but not to the light. Although the light is followed by the shock ,it adds no new information; the tone better predicts the impending shock.

That principle helps explain why classical conditioning treatments that ignore cognition often have limited success.

Biological predispositions Ever since Darwin, scientists have assumed that

all animals share a common evolutionary history and resulting commonalities in their makeup and functionality. Pavlov and Watson believed the basic laws of learning were essentially similar in all animals, so it should make a little difference between pigeons and humans. More than the early behaviorists realized, an animals capacity for conditioning is constrained by its biology. Each species' predispositions prepare it to learn the associations that enhance its survival.

Operant Conditioning

Operant Conditioning Operant conditioning explains and trains

behaviors such as an elephant walking on its hind legs or a child saying please.

Classical and operant conditioning include acquisition, extinction, spontaneous recovery, generalization, and discrimination.

Operant behavior produces rewarding or punishing stimuli (consequences).

Skinner’s Experiments B. F. Skinner was a college English major and an aspiring

writer who, seeking a new direction, entered graduate school in psychology. He went on to become modern behaviorism’s most influential and controversial figure. His work elaborated a simple fact of life that psychologist Edward L. Thorndike called the law of effect, which stated rewarded behavior is likely to recur.

He used the law of effect as a starting point and developed a “behavioral technology” that revealed principles of behavior control.

These principles allowed him to teach pigeons un-pigeon like behavior such as walking in a figure 8, playing Ping-Pong, and keeping a missile on course by pecking at a target on a screen.

Skinner’s Experiments cont. Skinner designed an operant chamber, known as a

Skinner Box which he used for his studies with rats and eventually pigeons.

The box has a bar or key that an animal presses or pecks at to release a reward of food or water, and a device that records these responses.

Shaping Behavior Uses reinforcers, such as food, to guide

an animal’s actions toward a desired behavior.

Makes the animal get closer and closer to where you want and rewards them.

Sometimes we as humans reward annoying behaviors unintentionally.

Types of Reinforcers Positive reinforcement strengthens a response

by presenting a typically pleasurable stimulus after a response.

Positive reinforcers include: praise, attention, hugs, food, etc.

Negative reinforcement strengthens a response by reducing or removing an aversive (undesirable) stimulus.

Negative reinforcers include: taking aspirin to relieve a headache and pushing the snooze button to silence an annoying alarm clock.

Primary and Conditioned Reinforcers Primary reinforcers, such as getting food

when hungry or being relieved of electric shock, are innately satisfying.

Conditioned reinforcers, also known as secondary reinforcers, are learned. They get their power through their association with primary reinforcers. Such as if a rat in a Skinner box learns that a light reliably signals that food is coming, the rat will work to turn on the light.

Immediate and Delayed Reinforcers Rats do not respond well to delayed reinforcers. The rat

in a Skinner box will engage in “unwanted” behavior (scratching, sniffing, and moving around) before performing the “wanted” behavior to receive the reward.

If the rat presses the bar, but if the researcher is distracted and delays the reinforcer for longer than 30 seconds, the rat will not learn to press the bar.

Unlike rats, humans do respond to reinforcers that are greatly delayed: the paycheck at the end of the week, the good grade at the end of the semester. To function effectively we must learn to postpone immediate rewards for greater long-term reward.

Reinforcement Schedules Many of the previous examples assume continuous

reinforcement: The desired response is reinforced every time it occurs. Under these conditions, learning occurs rapidly, but so does extinction.

Real life does not often provide continuous reinforcement, so why do people do the things they do? They do it because their efforts have occasionally been rewarded. This is called partial (intermittent) reinforcement schedule, in which the responses are sometimes reinforced, sometimes not. Initial learning is slower with intermittent reinforcement, but it produces greater persistence-greater resistance to extinction.

Reinforcement Schedules cont. Fixed-ratio schedules reinforce behavior after a set

number of responses much like people paid on a piecework basis.

Variable-ratio schedules provide reinforcers after an unpredictable number of responses. This is what gamblers experience and why it is so hard to extinguish.

Fixed-interval schedules reinforce the first response after a fixed time period. Like people checking more frequently for the mail as the delivery time approaches.

Variable-interval schedules reinforce the first response after varying time intervals.

Punishment The effect of punishment is opposite to that of

reinforcement. Punishment decreases a behavior, thus a punisher is any consequence that decreases the frequency of a preceding behavior, usually by administering an undesirable consequence or withdrawing a desirable one.

Physical punishment may increase aggressiveness by demonstrating that aggression is a way to cope with problems. This helps explain why so many aggressive delinquents and abusive parents come from abusive families.

Even though punishment suppresses unwanted behavior, it often does not guide one toward more desirable behavior. Punishment tells you what not to do; reinforcement tells you what to do.

Latent Learning Rats exploring a maze, with no obvious reward, are

like people sightseeing in a new town. The rats seem to develop a cognitive map, a mental representation of the maze. When an experimenter then places a reward in the maze’s goal box, the rats very quickly perform as well as rats that have been reinforced with food for running the maze.

During their explorations, the rats seemingly experience latent learning, learning that becomes apparent only when there is some incentive to demonstrate it.

Intrinsic Motivation Excessive rewards can undermine

intrinsic motivation, the desire to perform a behavior effectively and for its own sake. Intrinsically motivated people work and play in search of enjoyment, interest, self-expression, or challenge. Extrinsic motivation is the desire to behave in certain ways to receive external rewards or avoid threatened punishment.

Skinner’s Legacy Applications of operant conditioning can

be seen at school, in sports, at work, and at home.

Contrasting Classical and Operant Conditioning Both classical and operant conditioning

are forms of associative learning Classical conditioning is when an

organism associates different stimuli that it has no control over and responds to it.

Through operant conditioning, an organism associates operant behaviors with their consequences.

Learning by Observation Not all learning needs to occur through direct experience Observational learning is when we observe and imitate

others This learning type also applies to other species Cultural elements gained through imitation are called

memes Mirror neurons provide a neural basis for observational

learning Mirror neurons also serve language, help children learn

how to mime lip and tongue movements when forming new words.

They also allow us to infer another’s mental state

Bandura’s Experiments While a child is in the room, an adult beats a Bobo

boll for a long period of time. Later when the kid is frustrated and left alone, he also attacks the Bobo doll using the same words the adult used.

Watching the doll be beaten lowered the child’s inhibitions

What determines what we imitate are reinforcements and punishments

By looking we can determine a behaviors consequences

We are more likely to imitate those we see as similar to ourselves as successful or as admirable

Applications of Observable Learning Anti-social models may have anti-social effects Some learned things are that physical intimidation is

effective and free and easy sex is pleasurable with no consequences.

Also explains how abusive parents have aggressive kids and wife-battering fathers had parents who battered others.

Lessons learned as children are not easily forgotten Pro-social models can have positive effects on others Parents re also powerful models Those exposed to a hypocrite model tend to become

hypocrites themselves Television is a huge source of observational learning seeing

as most children when they are 18 watch more television than they spend in school

Applications of Observable Learning cont. T.V. allows for spread of culture between different countries Television portrays the real world poorly Before finishing elementary school, the average child has seen

8000 television murders and 100000 other acts of violence Violence is in 6 in every 10 programs, 78% goes unpunished,

58% did not show victims pain, and nearly half is seen as justified.

The more media violence a child sees, the more often they get into fights

The more violence watched, the more at risk they are for aggression and crime

Homicide rates doubled between 1957 and 1974 when television was introduced

Applications of Observational Learning cont. While there is a correlation, it does not prove

causation There is a possibility that violent programs

reflect violent behavior, not that it causes it The scientific community believes media

violence is a cause of violence, especially if caused by an attractive person who goes unpunished and causes no visible pain or harm.

Prolonged exposure to violence desensitizes viewers