ap psychology 3.1 learning. learning a lasting change in behavior or mental processes as the result...

AP Psychology

3.1 Learning

Learning

• A lasting change in behavior or mental processes as the result of an experience– Behavior can be observed– Mental processes are more difficult to study

Instincts vs. Learning

Instincts• Instincts are unlearned

behaviors due to evolutionary programming that are found in almost all members of a species

• Example…bears hibernate, geese migrate, salmon swim upstream to spawn

• Humans…debated, but…– Grasping reflex, sucking

reflex, pull hand away from fire, blinking

Learning• Represents a significant

evolutionary advance over instinctive behavior

• Enables humans to acquire new knowledge that can be transferred from one generation to another

Classical Conditioning• Ivan Pavlov (1849-1936)• Russian (later Soviet) physiologist who was

awarded a Nobel Prize in 1904 for his research on the digestive system of dogs

• While conducting experiments…Pavlov noticed that his dogs tended to salivate before food was actually delivered to their mouths

Classical Conditioning

• Spent 3 decades…532 experiments to studying classical conditioning

• Discovered classical conditioning (because first to be extensively studied in psych)

• Condition = learned• Elicit = cause / produce / bring forth

5 Components of Classical Conditioning

1. Unconditioned Stimulus (UCS) (US)- natural stimulus that reflexively elicits a

response without the need for prior learning- Pavlov used food as the US because it

produced naturally occurring salivation reflex- Unlearned stimulus = automatic

5 Components of Classical Conditioning

2. Unconditioned Response (UCR) (UR)- Unlearned response that is elicited by an US- In Pavlov’s experiments, salivation was the UR

5 Components of Classical Conditioning

3. Neutral Stimulus (NS)- Any stimulus that produces no conditioned

response prior to learning- In Pavlov’s experiments a ringing bell was

originally a neutral stimulus.

5 Components of Classical Conditioning

4. Conditioned Stimulus (CS)- The CS was originally the NS.- When systematically paired with the US, the

NS becomes a conditioned (learned) stimulus as it gains the power to cause a response

- In Pavlov’s experiments, the ringing bell became a CS when it began to produce the same salivating response that the food once produced

5 Components of Classical Conditioning

5. Conditioned Response (CR)- A CR is a learned response elicited by the CS- Pavlov called the process by which a CS elicits a

CR “acquisition”- In Pavlov’s experiments, he paired the ringing bell

with food. Originally a NS, the ringing bell became a CS when the dog reacted with a CR by salivating

- The dog’s salivation was both an UR and CR- **CC is most efficient when the CS immediately

precedes the US**

Example of CC

• Toilet flush and shower• US – hot water• UR – jumping back• NS – originally the toilet flush• CS – becomes the toilet flush• CR – jumping back

John B. Watson – “Little Albert”

• Taught baby Albert to fear a rat• NS - Rat• Reflex: US (loud noise) UR (cry)• Acquisition: NS + US UR• Acq. Demonstrated:– CS (rat) CR (cry)

• Shows how phobias and human emotions develop

Extinction

• Gradual weakening of a conditioned behavior when the CS is not followed by the US

• Example…Pavlov presented the ringing bell without food --- as a result, the ringing bell gradually lost its power to elicit the CR of salivation

Spontaneous Recovery• The reappearance of an extinguished CR after

a time delay• Example…Pavlov discovered that after a

period of time, his dogs began salivating when they heard the sound of the bell **Note – the CR reappears at a lower intensity

• This shows how difficult it can be to eliminate a CR

Generalization

• Occurs when stimuli that are similar to the original stimulus also elicit the CR (when a new stimulus was not paired with the US

• Example…Pavlov found that a dog conditioned to a low-pitched tone would also respond to a high-pitched tone

Discrimination

• Ability to distinguish between two similar stimuli

• Example…students have learned different responses to the sound of bells in the classroom, cell phones, and front doors

• Example…gardeners demonstrate discrimination when they respond differently to weeds and to flowers

Generalization/Discrimination

• Example…• A young boy is bitten by his neighbors dog• He runs away when he sees any neighborhood

dog (Generalization)• He still enjoys playing with his family's pet

collie (Discrimination)

Higher-order conditioning• Aka – second-order conditioning• A CS from one learning trial is paired with a new • The new US becomes the new CS capable of

eliciting the CR even though it has never been paired with the US

• Example… Pavlov CC a dog to salivate to the sound of a ticking metronome . He then paired the metronome with a black square. After several pairings, the black square produce salivation even though it had never been paired with food.

A rat has already been conditioned to associate the blue stick with a cat odor(US). A red light is flashed on before the blue stick is placed in its cage. The rat displays a second-order conditioned

response when just the red tight is turned on.

Taste Aversion

• A CC dislike for and avoidance of a particular food that develops when an organism becomes ill after eating the food

• Many people have experienced vivid examples of taster aversion

Taste Aversion

• Aka – Aversive Conditioning• NS: food• Reflex: US (stomach virus) UR (vomiting)• Acquisition: NS + US UR• Acq. Demonstrated:– CS (food) CR (vomiting – sick)

Taste Aversion• John Garcia experiments (1917)• Conducted experiments to demonstrate that

taste aversions could be produced in laboratory rats

• NS (saccharin-flavored water)• US (drug) -> UR (gastrointestinal distress)• After recovering from illness, the rats refused

to drink the flavored water (taste aversion)

Taste Aversion

• Garcia’s findings challenged two basic principles of CC– 1. conditioning only required a single pairing– 2. conditioning does not always need to be

separated by seconds – he separated the stimuli by several hours

**demonstrated there are biological constraints on conditioning!

Taste Aversion

• Example – Wolves and Sheep

Operant Conditioning

• Limitations on Classical Conditioning…– CC focuses on existing

reflexive behaviors that are automatically elicited

– Learning, however, involves new behaviors or voluntary actions that classical conditioning cannot explain

Edward L. Thorndike

• His studies on baby chicks and cats were the first systematic investigation of animal learning

• Focused on how voluntary behaviors are influenced by their consequences

Thorndike and the Law of Effect

• Responses that lead to satisfying outcomes are more likely to be repeated

• Responses followed by unpleasant outcomes are less likely to be repeated

Thorndike – “Cat in a Puzzle Box”

BF Skinner

• Behaviorist who believed that psychologists should focus on observable behavior that could be objectively measured and verified

Skinner and Operant Conditioning

• Formulated the principle of Operant Conditioning

• OC – any “active behavior that operated upon the environment to generate consequences”

• OC is a learning process in which behavior is shaped and maintained by consequences (rewards or punishments) that follow a response

• CC (SR) / OC (RS)

Skinner Box

• The box is a chamber that includes at least one lever, bar, or key that the animal can manipulate.

• When the lever is pressed, food, water, or some other type of reinforcement might be dispensed.

• Other stimuli can also be presented including lights, sounds, and images.

• In some instances, the floor of the chamber may be electrified

Skinner Box

Operant Conditioning: Reinforcement

• Reinforcement occurs when a stimulus (reinforcer) follows an active behavior or response

• The reinforcer increases the probability that the behavior or response will be repeated

Positive Reinforcement

• Behavior is followed by the addition of reinforcing stimulus

• Stimulus increases the probability that the response will occur again

• NOTE – positive does not mean “good” or “desirable”

• Positive like a “+” sign– Indicates a response is strengthened because

something is added

Examples of “+” Reinforcement

• Flawless performance is school play (the operant) / your drama coach applauds and exclaims “Bravo!” reinforcing stimulus)

• You earn a “A” on an AP Psychology Test (the operant) / your teacher writes you a letter (reinforcing stimulus))

Negative Reinforcement

• Behavior or response is followed by the removal of an adverse stimulus

• NOTE - negative does not mean “bad” or “undesirable”

• Negative like a “-” sign– Indicates that a response is strengthened because

something is subtracted or removed

Examples of “-” Reinforcement

• You take out the garbage (the operant) to avoid your mother’s repeated nagging (aversive stimulus)

• You put on sunscreen (the operant) to avoid getting sunburned (aversive stimulus)

• You give your little brother a candy bar (the operant) to prevent him from crying (aversive stimulus)

• Your little sister is crying (the operant), you hug her and she stops crying (aversive stimulus)

Premack Principle

• David Premack• Stated that the

opportunity to engage in a preferred activity can be used to reinforce a less-preferred activity

Premack Principle Examples

• You enjoy playing video games far more than studying for the ACT.

• Knowing this, you tie the less-preferred activity (studying for the ACT) to your preferred activity (playing video games)

• You enjoy eating ice cream for dessert far more than eating vegetables.

• Knowing this, your mother ties the less-desired activity (eating veggies) to your preferred activity (eating ice cream)

Types of Reinforcers• Primary Reinforcers– Naturally reinforcing for a species– Ex…food, water, shelter, sex

• Secondary Reinforcers– Gains effectiveness by a learned association with

primary reinforcers– Ex…money

Types of Reinforcers

• Token Economy– Individuals rewarded with tokens that can act as

secondary reinforcers. – The tokens can be redeemed for rewards and

priveledges– Elementary Teachers – gold stars

Continuous Reinforcement• Reinforcement schedule in which all correct

responses are reinforced• Responses extinguish faster when they are

learned through this

Shaping• Technique of strengthening behavior by

reinforcing successive approximations of a behavior until the entire correct routine is displayed

• Used by athletic coaches and animal trainers

Intermittent Reinforcement • Rewarding of some, but not all, correct

responses• Advantages– Most efficient way to maintain behaviors already

learned– Are very resistant to extinction– Example – Gambling (very difficult habit to

extinguish)

Schedule of Reinforcement

Ratio Schedules• Based on number of

responses

• Fixed ratio• Variable ration

Interval Schedules• Based on responses made

within a certain time period

• Fixed interval• Variable interval

Fixed Ratio Schedule

• Reinforcement occurs after a predetermined set of responses– Produce high response

rates (brief drop-off after reinforcement)

• Examples…– an employer pays workers

every three baskets of fruit

– Mario Bros – 100 coins = life

Variable Ratio Schedule

• Reinforcement is unpredictable because the ratio varies

• High response rates and resistant to extinction

• Examples…– Casino slot machines– Golf– Door-to-door salesman

Fixed Interval Schedule

• Reinforcement occurs after a predetermined time has elapsed– Moderate response rates

followed by a flurry of activity near the end of each interval

• Examples…– Employers paying

employees every two weeks

– Teachers who give a quiz every week

– Baking a cake

Variable Interval Schedule

• Reinforcement occurs unpredictably since the time interval varies– Produce low but steady

response rates

• Examples…– Teachers and pop

quizzes– Fishing– Parent attending to

children crying

Punishment

• Process by which a behavior is followed by an aversive consequence that decreases the likelihood the behavior being repeated.

• Is NOT the same as reinforcement– Punishment decreases the

likelihood of a behavior– Reinforcement increases the

likelihood of a behavior

Positive Punishment

• Application or adding of an aversive stimulus after a response

• Examples…– You arrive late for work (operant) you are docked

pay (aversive stimulus)– You show off your knowledge by answering all the

teacher’s questions (operant) a popular girl makes a snide remark about you (aversive stimulus)

Negative Punishment (Omission Training)• Removal or subtraction of a reinforcing stimulus

(privilege) • NOT negative reinforcement!

– Negative punishment makes a behavior less likely to happen– Negative reinforcement makes a behavior more likely to

happen• Examples…

– You arrive at work late (operant) and are sent home without pay (loss of reinforcing stimulus)

– You show off your knowledge by answering all the teacher’s questions (operant) and the popular girl doesn’t invite you to her party (loss of reinforcing stimulus)

– Person who was caught driving while intoxicated also loses her driver’s license

Drawbacks of Punishment• Can produce undesirable results (fear, hostility,

aggression)• Often produces temporary change• Can produce Learned Helplessness– Occurs when a learner feels that it is impossible to

escape punishment– Leads to passive feeling hopelessness that may lead

to depression• Example…– A student is doing poorly in AP Psych– “No matter what I do, I’m going to fail”

Effective Use of Punishment

• Should be delivered immediately after the offensive behavior

• Should be certain• Should be limited and sufficient so that it “fits

the crime”• Should focus on the behavior, not the

character, or the offender

Comparing CC and OC

Classical Conditioning

• Pioneers– Pavlov and Watson

• Types of Behavior– Involuntary responses

• Timing of Stimuli– Precedes the response– S R

• Use of Rewards/Punishment– Does not use

Operant Conditioning• Pioneers

– Thorndike and Skinner

• Types of Behavior– Voluntary responses

• Timing of Stimuli– Follows the response– R S

• Use of Rewards/Punishment– Based on