Chapter 8-Learning Learning -...

Chapter 8-Learning

8-1

1. Discuss the importance of learning and the process of learning associations.

2. Describe the general process of classical conditioning as demonstrated by Pavlov’s experiments.

3. Explain the processes of acquisition, extinction, spontaneous recovery, generalization, and discrimination.

4. Discuss the importance of cognitive processes and biological constraints in classical conditioning.

5. Explain the importance of Pavlov’s work and describe how it might apply to an understanding of human health and well-being.

8-1

Learning

! Learning

! relatively permanent change in an organism’s behavior due to experience

z Behaviorism -The attempt to understand observable activity in terms of observable stimuli and observable responses

z John B. Watson (1913)

z B.F. Skinner (1938)

8-1

Association

! We learn by association! Our minds naturally connect events that occur in

sequence

! Associative Learning! learning that two events occur together

! two stimuli

! a response and its consequences

! 2 types (classical and operant

! conditioning)

! conditioning- the process of learning associations

! **associative learning is not the only way we learn

! we also learn from other peoples experience and examples – called observational learning

8-1

Association

! Learning to associate two events

Event 1 Event 2

Sea snail associates splash with a tail shock

Seal learns to expect a snack for its showy antics

8-1

Classical or Pavlovian

Conditioning

! We learn to associate two stimuli

8-1

Operant Conditioning

! We learn to associate a response and its consequence

8-1

Classical Conditioning

! Ivan Pavlov

! 1849-1936

! Russian physician/ neurophysiologist

! Nobel Prize in 1904

! studied digestive secretions

8-1


! naturally, if you put food in a dog’s mouth he will salivate

! Pavlov noticed the dogs began to salivate to associated stimuli

! ex’s. sight of food, sight of lab worker who fed the dogs, sound of footsteps, etc.

! Pavlov decided this needed to be looked into

! cut a hole in the dogs cheek and attached a tube to measure salivation

8-1


! Pavlov’s device for recording salivation

8-1

Pavlov’s Classic

Experiment

Before Conditioning

During Conditioning After Conditioning

UCS (foodin mouth)

Neutralstimulus(tone)

Nosalivation

UCR (salivation)

Neutralstimulus(tone)

UCS (foodin mouth)

UCR(salivation)

CS(tone)

CR (salivation)

8-1


! Classical Conditioning

! organism comes to associate two stimuli

! a neutral stimulus that signals an unconditioned stimulus begins to produce a response that anticipates and prepares for the unconditioned stimulus

8-1

Behaviorism

! John B. Watson

(“Little Albert” Study)

! viewed psychology as objective science! generally agreed-upon

consensus today

! recommended study of behavior without reference to unobservable mental processes

! not universally accepted by all schools of thought today

8-1


! Unconditioned Stimulus (UCS)

! stimulus that unconditionally--automatically and naturally--triggers a response (food)

! Unconditioned Response (UCR)

! unlearned, naturally occurring response to the unconditioned stimulus

(salivation in response to food in mouth)

8-1


! Conditioned Stimulus (CS)! originally irrelevant/neutral stimulus that,

after association with an unconditioned stimulus, comes to trigger a conditioned response (tone)

! Conditioned Response (CR)! learned response to a previously neutral

conditioned stimulus

(salivation in response to the tone)

8-1


! Acquisition

! the initial stage in classical conditioning

! the phase where the neutral stimulus (NS) becomes associated with the unconditioned stimulus (UCS) so that the neutral stimulus comes to elicit a conditioned response

! in operant conditioning, the strengthening of a reinforced response

! Q: What is the relationship b/w the time interval b/w presentation of NS + UCS and the rate of acquistion???????

! (must have stimulus contiguity – occur together in space & time)

8-1


! Pavlov had to find out how much time should lapse between the presentation of the NS and the US to better understand acquisition

! found it would work up to ! a second before the pairing

! later studies concluded classical conditioning is biologically adaptive

! ex. Snapping twig (CS) may signal a predator to a deer (US)

! conditioning serves a function

! helps animals respond to cues that help it gain food,

avoid danger, locate mates, and reproduce

8-1


UCS(passionate kiss) UCR

(sexualarousal)

CS(onionbreath)

CS(onion breath) CR

(sexualarousal)

UCS(passionate Kiss) UCR

(sexualarousal)

8-1


Q: What happens when the CS is repeatedly presented without the UCS?

8-1


! Extinction

! diminishing of a CR

! in classical conditioning, when a UCS does not follow a CS

! ex. Dog stops salivating at sound of bell if bell keeps happening and no food is given

! Note -Extinction doesn’t equal unlearning

! --Length of extinction is det by strength of bond

! in operant conditioning, when a response is no longer reinforced

8-1 Classical Conditioning

Strengthof CR

Pause

Acquisition(CS+UCS)

Extinction(CS alone)

Extinction(CS alone)

Spontaneousrecovery ofCR

8-1


! Spontaneous Recovery

! reappearance, after a rest period, of an extinguished CR

! ex. Dog salivates at the sound of the bell if he does not hear a bell for several hours

! Renewal Effect-if response is extinguished in different environment than acquired, response will reappear in original environment

! Generalization

! tendency for stimuli similar to CS to elicit similar responses

! ex. Dentists drill v. jeweler’s

! ex. Dog salivates in resp to windchimes

! ex. Child attacked by a Doberman may also fear a Labrador Retriever

! Ex. “Little Albert”: rabbit, dog, Santa Claus mask, Watson’s Hair

8-1


! Discrimination

! in classical conditioning, the learned ability to distinguish between a CS and other stimuli that do not signal a UCS

! Ex. Dog stops salivating at windchimes and only salivates in resp to tuning fork

! ex. Child attacked by a Doberman will not fear the friendly Labrador Retriever

8-1

Generalization

Drops of salivain 30 seconds

60

50

40

30

20

10

0Hindpaw

Pelvis Shoulder Frontpaw

Thigh Trunk Foreleg

Part of body stimulated

8-1

Nausea Conditioning in

Cancer Patients

UCS(drug)

UCR(nausea)

CS(waiting room)

CS(waitingroom) CR

(nausea)

UCS(drug)

UCR(nausea)

8-1

! Are the laws of learning universal across all animals?

! No, there are biological constraints on an organism’s capacity for conditioning

>>Biologically predisposed to learn associations that enhance survival

Cognitive & Biological

Processes in CC

8-1

Cognitive Processes

Robert Rescorla & Richard Wagner – role of expectancy of UCS after pres of CS

! Also: why antabuse doesn’t work to treat alcoholism

Bio Predisp

Garcia & Koelling-taste aversion studies

! Rats attributed illness to flavored H20 not cage which was radiated, also avoided even if not sickened until hours later

! Human taste averse to mussels

! Shows why CS & UCS don’t have to be tightly paired for conditioning to take place

Cognitive & Biological

Processes in CC (321-322)

8-1

1. Flooding - Exposing someone to harmless

stimuli which they fear

! Ex. Tying someone with arachnophobia down and dumping spiders on her – she will learn the spiders do not plan to harm her

! usually unpleasant to the person being flooded

Classical Conditioning – Phobias &

Therapy 3 Ways to use CC to Overcome Fears

8-1

Classical Conditioning –

Phobias & Therapy

! 2. Counterconditioning- 2 types (Sys Desens & Aversive Cond)

! Systematic Desensitization –

! pairing an unpleasant stimulus with an enjoyable stimulus

>>Ex. Giving a child scared of a dog a twinkie every time he plays with a dog

! Teaching someone relaxation techniques then gradually exposing them to the feared stimulus as their level of relaxation increases (progessive relaxation)

! Ex. Showing a photo of a spider as soon as she can relax, put a spider in a jar across the room, as soon as she can relax

8-1

Classical Conditioning –

Phobias & Therapy

Aversive Therapy (p692) - reverse of systematic desensitization (this therapy isn’t used to treat phobias but to condition aversion in subject to something they should avoid)

EX. To stop biting you nails--wearing nail polish

Other ClassicalCond Application:

CC immunosuppression (Ader) (559)

8-1

8-2 Operant Conditioning

8-2

6. Describe the process of operant conditioning, including the procedure of shaping, as demonstrated by Skinner’s experiments.

7. Identify the different types of reinforcers and describe major schedules of partial reinforcement.

! .

8-2


! Operant Conditioning! type of learning in which behavior is

strengthened if followed by reinforcement or diminished if followed by punishment

! CC involves respondent behavior

caused by automatic responses to stimuli

! OC involves operant behavior

! behavior that operates on the environment, producing consequences

! therefore, OC involves things we can control

8-2


! Law of Effect

! Thorndike’s principle that behaviors followed by favorable consequences become more likely, and behaviors followed by unfavorable consequences become less likely <<puzzle box>>

8-2


! B.F. Skinner (1904-1990)

! elaborated Thorndike’s Law of Effect

! says rewarded behavior is likely to recur

! developed behavioral technology

8-2

Operant Chamber

! Skinner Box

! chamber with a bar or key that an animal manipulates to obtain a food or water reinforcer

! contains devices to record responses

8-2


! Skinner used the concept of shaping to teach animals to do things

! Shaping - an operant conditioning procedure where reinforcers are used to gradually guide an animal toward a desired behavior

! Builds on existing behavior

! Reward successive approximations towards final desired behavior

chaining

8-2


! Reinforcer- any event that strengthens the behavior it follows

! often times they are rewards, but they do not have to be

8-2


Snooze bar

8-2

Get it straight

z Positive Reinforcement- Reinforcement by

Adding

z Negative Reinforcement- Reinforcement by

Removing

z Positive Punishment- Punishment by Adding

z Negative Punishment- Punishment by

Removing

38

Principles of

Reinforcement

! Primary Reinforcer

! innately reinforcing stimulus

! i.e., satisfies a biological need

! (eg. food, H2O)

! Conditioned Reinforcer (secondary reinforcer)

! stimulus that gains its reinforcing power through its association with primary reinforcer

! (eg. money, praise, tokens in “token economy” behavior modification program)

8-2

Principles of Reinforcement- Immediate v. Delayed

! Immediate vs. Delayed

! 1. Immediate

! works best for animals, also works w/ humans

! 2. Delayed

! will work with humans

8-2

Schedules of Reinforcement-Continuous v. Partial

! Continuous Reinforcement

! reinforcing the desired response each time it occurs

! Partial (Intermittent) Reinforcement

! reinforcing a response only part of the time

! results in slower acquisition

! greater resistance to extinction

* 4 types of partial reinforcment schedules

8-2

! Fixed Ratio (FR)! reinforces a response only after a specified

number of responses

! faster you respond the more rewards you get

! different ratios

! very high rate of responding

! ex. Factory worker may be paid a $5 bonus for every 1000 pieces he completes in a day

! resting reduces rewards

! overall output increases on this schedule

Schedules of Reinforcement-4 Types of Partial: FR, VR, FI, VI

8-2

! Variable Ratio (VR)

! reinforces a response after an unpredictable number of responses

! like gambling (slot machine), fishing

! very hard to extinguish because of unpredictability (resistant to extinction)


8-2

! Fixed Interval (FI)

! reinforces a response only after a specified time has elapsed

! response occurs more frequently as the anticipated time for reward draws near (ie. Getting mail, paycheck every 2 weeks)


8-2

! Variable Interval (VI)

! reinforces a response at unpredictable time intervals

! produces slow steady responding

! like pop quiz, bonus check @ Christmas


8-2

Schedules of

Reinforcement

Variable Interval

Number of responses

1000

750

500

250

010 20 30 40 50 60 70

Time (minutes)

Fixed Ratio

Variable Ratio

Fixed Interval

Steady responding

Rapid respondingnear time forreinforcement

80

8-2

8-3 Operant Cond Cont’d &

Observational Learning

8-3

8. Discuss the effects of punishment on behavior.

9. Discuss the importance of cognitive processes and biological predispositions in operant conditioning.

10. Explain why Skinner’s ideas were controversial, and describe some major applications of operant conditioning.

11. Describe the process of observational learning as demonstrated by Bandura’s experiments, and discuss the impact of antisocial and prosocial modeling.

.

8-3

Punishment

! Punishment

! aversive event that decreases the behavior that it follows

! not the same as negative reinforcement

! punishment does not teach alternate acceptable behaviors

! may lead to anger and frustration

! Should be swift, sufficient & certain to be most effective

8-3

Punishment

8-3

Get it straight

z Positive Reinforcement- Reinforcement by

Adding

z Negative Reinforcement- Reinforcement by

Removing

z Positive Punishment- Punishment by Adding

z Negative Punishment- Punishment by

Removing

50

Cognition and Operant

Conditioning

! Cognitive Map (EC Tolman)

! mental representation of the layout of one’s environment

! Example: after exploring a maze, rats act as if they have learned a cognitive map of it

>>contradicts Skinner’s discounting of cognitive processes

! Latent Learning

! learning that occurs, but is not apparent until there is an incentive to demonstrate it

8-3

Latent Learning

8-3


Conditioning

! Intrinsic Motivation

! Desire to perform a behavior for its own sake and to be effective

! Extrinsic Motivation

! Desire to perform a behavior due to promised rewards or threats of punishments

8-3


Conditioning

! Overjustification Effect

! the effect of promising a reward for doing what one already likes to do

! the person may now see the reward, rather than intrinsic interest, as the motivation for performing the task

8-3

Operant Learning

! Biological Predispositions and Constraints in Operant Cond

Again: Biological constraints predispose organisms to learn associations that are naturally adaptive

! Hamsters can be op conditioned to dig using food as reinf b/c digging is a natural behavior when searching for food. Cannot cond hamster to wash face.

! Pigeons flap wings to avoid shock (neg reinf) and peck for food reward(pos reinf) but won’t peck to avoid shock or flap wings to get food

8-2


! Applications of Operant Conditioning

! Token Economy as a Behavior Modification System

! Adaptive Online Testing

In workplace:

Boost productivity by making desired behaviors well-defined and achievable. Use Immediate reinf. (IBM)

8-2

Operant vs Classical Conditioning

8-3


! Observational Learning (Albert Bandura Study)! learning by observing others

! Modeling! process of observing and imitating a specific behavior

! Obs Learning and modeling start early -9 mo old – models play behaviors

14 mo old – models tv behaviorsLikely to imitate those we perceive as 1. similar to ourselves

2. successful3. admirable

8-3


! Mirror Neurons

! frontal lobe neurons that fire when performing certain actions or when observing another doing so

! may enable imitation, language learning, and empathy

8-3


! ex. -Albert Bandura –guru of observational learning

! -did the Bobo Doll Exp.

! found that children who see adult violently beating an inflated doll are more likely to do so themselves than those who don’t

8-3


z Applications of Bandura’s research! lessons we learn as children are not easily unlearned as adults

z Negative – Anti-Social Models

z Positive – Prosocial Models

! Prosocial Behavior! positive, constructive, helpful behavior! opposite of antisocial behavior

! prosocial models may also have prosocial effects! ex. Gandhi and Martin Luther King Jr.

8-3


! models are most effective when actions and words are consistent

! children often learn hypocritical ways from parents

! Kids imitate hypocrisy – doing what is done and saying what is said

! To encourage children to read, read to them, let them see you read, and surround them with reading materials

8-3


z !18 most kids spend more time watching tv than in school

z 90% of houses – 3 or more tvs, exp Contradictory reports b/w what parents say their kids are watching and what they’re actually watching

z Primetime – 3 viol acts/ hr, Sat a.m. 18/ hr

z Before leaving elem sch, child has seen 8000 tv murders & 100,000 viol acts

z Kids who watch 3 hours tv/ day @ 14, commit 5x aggressive acts b/w16-22 as 14 yr old who watches 1 hr or less

z Violent acts correlate with the adoption of TV (1957-1974 violent acts doubled)

z --more evidence: regions late in getting tv had a later homicide rate jump that correlated with TV adoption time

z Biggest problem w/ tv could be opportunity costs (remember delinq daydream less – daydreaming as sub for impulsive behavior)

8-3


z 700% inc in boys’ violent play after watching “Power Rangers”

8-3

Chapter 8-Learning Learning -...

Documents

Transcript of Chapter 8-Learning Learning -...