UNIT 7 - LEARNING PPT 11.8.12.pptx

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UNIT 7: LEARNING

Introduction

• _{Adaptability – our capacity} to learn new behaviors that help us cope with changing circumstances

– _{May be humans most} important characteristic

• _{Learning – a relatively} permanent change in an organism’s behavior due to experience

Introduction

• _{Three types of learning:}

– Classical Conditioning – Operant Conditioning – Observational Learning

• _{Aristotle, Locke, and David} Hume all agree:

– _{“We learn by association”} – _{Our minds naturally connect}

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UNIT 7: LEARNING

How Do We Learn?

• _{Behaviors can also become}

associated with contexts

Example: we may crave popcorn when we enter a Theatre

Example: some people only

smoke when they are drinking

• _{Associative Learning –}

learning that certain events occur together

– _{Thunder and lightning} – _{Christmas and presents}

• _{Conditioning – process by}

which we learn associations

• _{Classical Conditioning – a type}

of learning in which one learns to link two or more stimuli and anticipate events

– _{Example: Pavlov’s tuning fork} and meat powder both

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UNIT 7: LEARNING

• _{Operant Conditioning – a}

type of learning where one learns to associate a response (our behavior) and its

consequence and thus to

repeat acts followed by good results and avoid acts

followed by bad results

– Example: a seal receives a treat (fish) each time it successfully balances a ball on it’s nose

• _{Observational Learning – a} type of learning where we learn from others’

experiences

– _{Example: if the first ten} people that finish taking a test get a treat, test takers will work more quickly to attain the treat

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UNIT 7: LEARNING

Classical Conditioning

• _{Ivan Pavlov (1849-1936) –}

responsible for the

development of classical conditioning

– Russian who studied digestive system

– _{Won Russia’s first Nobel prize in} 1904

– _{Studied salivation habits of dogs} – Paired “neutral” events with

food in dog’s mouth

• _{John B. Watson (1913) –} said psychology should be an objective science based on observable behavior

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UNIT 7: LEARNING

• _{Unconditioned}

– Not trained/learned – Happens naturally – Unlearned

• _Conditioned

– _Trained – _Learned

– _{Doesn’t happen naturally}

• _{Stimulus – something that} elicits a response

• _{Response – a behavior that} happens as a result of a

stimulus

– Example:

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UNIT 7: LEARNING

• Unconditioned Stimulus (US) – a stimulus that unconditionally (naturally and automatically) triggers a response

– _{Ex: food in mouth}

• _{Unconditioned Response (UR) –}

the unlearned, naturally occurring response to a US

– _{Ex: salivation when food is in}

mouth

• _{Conditioned Stimulus (CS) – an}

originally irrelevant stimulus that, after association with a US, comes to trigger a CR

– Ex: Sound of a tone

• _{Conditioned Response (CR) –}

the learned response to a previously neutral (but now conditioned) stimulus (CS)

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UNIT 7: LEARNING

Conditioning Processes

• _{Pavlov worked on the}

following processes for 30 years:

_________________________ • _Acquisition

• _Extinction

• _{Spontaneous Recovery} • _{Generalization}

• _{Discrimination}

Conditioning

• _{Acquisition: in classical}

conditioning, the initial stage, when one links a neutral

stimulus and an

unconditioned stimulus so that the neutral stimulus begins triggering the

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UNIT 7: LEARNING

Acquisition

• _{How much time should}

elapse between presenting the neutral stimulus (tone, light, touch) and the

unconditioned stimulus?

– _{About ½ second works well}

• _{Order is important}

– If US appeared before the CS, conditioning probably would not happen

Acquisition

• Conditioning helps animals survive and reproduce

• Higher-Order Conditioning – also called Second-Order Conditioning, a new neutral stimulus can become a new conditioned stimulus

– Tends to be weaker

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UNIT 7: LEARNING

Extinction & Spontaneous Rec.

• _{Extinction – in C.C. the}

diminishing of a conditioned response (CR)

– happens when an (US-food) does not follow a (CS-tone) – in O.C. happens when a

response is no longer reinforced

Extinction & Spontaneous Rec. • _{Spontaneous Recovery – the}

reappearance, after a pause, of an extinguished conditioned response (CR)

– _{Ex. – dog begins to respond to tone} again

• _{Discrimination – in C.C. the learned} ability to distinguish between a conditioned stimulus and stimuli that do not signal an

unconditioned stimulus

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UNIT 7: LEARNING

Extending Pavlov

• _{Pavlov and Watson –} underestimated the

importance of cognitive processes (thoughts,

perceptions, expectations) and biological constraints on an organism’s learning capacity

Cognitive Processes

• _{Robert Rescorla & Allan}

Wagner (1972) – showed animals can learn the

predictability of an event

– Presented a light, then tone, then shock

– Rats did not respond with fear to the light; the tone was met with fear

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UNIT 7: LEARNING

Biological Predispositions

• _{Gregory Kimble (1981) –} said an animals capacity for conditioning is constrained by its biology; each species’ predispositions prepare it to learn the associations that enhance its survival

• _{John Garcia – challenged} idea that all associations can be learned equally well

– First did radiation tests on rats in 1960s; rats weren’t drinking water from plastic bottles anymore

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UNIT 7: LEARNING

• _{Garcia’s Findings:}

– _{Even if sickened several hours} after tasting a novel flavor, rats would thereafter avoid the flavor

– _{Sickened rats developed}

aversions to tastes, but NOT to sights or sounds

– _{Contradicted idea that US must} immediately follow CS; makes adaptive sense for rats being they use taste to identify food

• _{Another Garcia Study:}

– _{Coyotes and Wolves were}

tempted into eating sheep carcasses laced with poison

– _{Both developed an aversion to}

eating sheep meat

– _{Eventually wolves penned with a}

live sheep learned to fear the sheep

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UNIT 7: LEARNING

Pavlov’s Legacy

• _{By today’s standards,}

Pavlov’s ideas were correct, but incomplete

• _{Relevance today: classical} conditioning is one way that virtually ALL organisms

learn to adapt to their environment

Pavlov’s Legacy

• _{Pavlov showed us how a}

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UNIT 7: LEARNING

Applications of Classical Conditioning

• _{Former drug users often}

feel a craving when they are again in a drug-using

context

• _{When a certain taste}

accompanies a drug that influences an immune

response, the taste by itself can come to trigger the

same immune response

• _{Watson (1913) had idea} that human emotions and behaviors are mainly a

bundle of conditioned responses.

• _{Watson and Rosalie Raynor} worked with 11-month-old “Little Albert” to test how specific fears may be

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UNIT 7: LEARNING

• _{“Little Albert” Study}

– Initially Albert feared loud noises but not white rats – In experiment, when Albert

reached for white rat a loud noise was presented

– After several trials, Albert cried at the sight of the rat

– 5 days later, Albert showed generalization by showing fear toward a rabbit, dog, etc. but not dissimilar objects

• _{Watson ended up marrying} Raynor and he worked for Maxwell House coffee, helping to introduce the “coffee break” as an

American custom

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UNIT 7: LEARNING

Watson’s Classic Boast:

• _{“Give me a dozen healthy} infants, well-formed, and my own specified world to bring them up in and I’ll guarantee to take any one at random and train him to become any type of

specialist I might select -

doctor, lawyer, artist,

merchant-chief, and, yes, even beggar-man and thief, regardless of his talents, penchants, tendencies,

abilities, vocations, and race of his ancestors.”

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UNIT 7: LEARNING

• _{Classical conditioning forms} associations between two stimuli; involves respondent behavior, actions that are automatic responses to a stimulus

Operant Conditioning

• _{In Operant conditioning,}

organisms associate own actions with consequences; actions followed by reinforcers increase; actions followed by punishers decrease.

• _{Called “operant” because it is}

behavior that operates on the environment to produce

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UNIT 7: LEARNING

Skinner’s Experiments • _{B.F. Skinner (1904-1990)}

• _{Edward L. Thorndike (1874-1949)}

• _{Thorndike’s Law of Effect:} rewarded behavior is likely to recur

• _{Skinner trained pigeons to:}

– Walk a figure 8 – Play ping-pong

– Keep a missile on course

Skinner’s Experiments

• _{Thorndike trained cats to} find their way out of a “puzzle box”

• _{Skinner created an “operant} chamber” also known as a “Skinner box”

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UNIT 7: LEARNING

Shaping Behavior

• _{Shaping – in operant}

conditioning, reinforcers

guide behavior toward closer and closer approximations of the desired behavior

– _{It is important to first watch} how the animal naturally behaves, and then build on existing behaviors

– _{Example: We can’t shape an} elephant to jump rope

Shaping Behavior

• _{Giant rats have been} shaped to sniff out land mines in Mozambique

• _{Pigeons have been shaped} to recognize human faces among other stimuli

• _{Among humans, whining is} reinforced when we react to it – a whining child

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UNIT 7: LEARNING

Types of Reinforcers

• _{Reinforcer – in O.C. any} event that strengthens

(increases frequency of) the behavior it follows

– _{Examples include food,} money, praise, attention,

being yelled at, borrowing the car, etc.

– _{What is reinforcing to one} person may NOT be to the next

Types of Reinforcers • _{Positive Reinforcement}

– _{Strengthens a response}

– Presents a typically pleasurable stimulus

• _{Negative Reinforcement}

– _{Strengthens a response}

– _{Reduces or removes something}

undesirable or unpleasant

• _{Negative reinforcement is NOT} the same as punishment

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UNIT 7: LEARNING

• _{Primary Reinforcers – an} innately reinforcing stimuli; one that satisfies a

biological need

– _{Getting food when hungry} – _{Having a headache go away}

• _{Conditioned Reinforcers –} also called Secondary

Reinforcers – gains its

reinforcing power through association with primary reinforcer

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UNIT 7: LEARNING

• _{Rats will not learn to}

respond if delay between behavior and reinforcement is more than 30 seconds

• _{Humans DO respond – it’s} called “delayed

gratification”

– Examples: paycheck at end of month, grades at end of Tri, trophy at end of season

• _{Continuous Reinforcement} – reinforcing desired

response every time it occurs

• _{Partial (Intermittent)}

Reinforcement – reinforcing desired response only part of the time; slower

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UNIT 7: LEARNING

Reinforcement Schedules

• _{Real life rarely provides} continuous reinforcement • _{Partial Reinforcement}

examples:

– _{Fishing – don’t get a fish} every cast

– _{Sales – don’t make a sale to} every prospective consumer – _{Slot Machines – reward}

gamblers occasionally and unpredictably

• _{Partial Reinforcement} (Cont’d):

– Occasionally giving in to a child’s tantrums is perfect way to reinforce that

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UNIT 7: LEARNING

• _Fixed-ratio

– Reinforces behavior after a set # of responses

– Ex: get a free coffee after you buy 10

– High rate of responding

• _{Variable-ratio}

– _{Reinforces behavior after} unpredictable # of responses – _{Ex: slot machines and anglers} – _{High rate of responding}

Reinforcement Schedules • _{Fixed-interval}

– _{Reinforces the first response after a}

given time period

– Ex: more frequently checking for the mail as delivery time nears

– Produces choppy start-stop pattern of responding

• _{Variable-interval}

– _{Reinforces the first response after}

varying time intervals

– _{Ex: “You’ve got mail” after}

persistently checking email

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UNIT 7: LEARNING

Punishment

• _{Punishment – an event that} decreases the behavior that it follows

– Opposite of reinforcement, which increases the behavior it follows

Punishment

• _{Studies show that criminal} behavior, much of it

impulsive, is not deterred by the threat of severe sentences

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UNIT 7: LEARNING

Parenting and Punishment

1. Punished behavior is

suppressed, not forgotten

-spanking a child for swearing may reinforce parents’ punishing behavior

2. Punishment teaches discrimination

-child doesn’t learn NOT to

swear – just learns not to swear around parents

Parenting and Punishment

3. Punishment can teach fear

-child associates fear with undesired behavior, but also with person who delivers punishment or the place it occurred

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UNIT 7: LEARNING

Reinforcement & Punishment

• _{Punishment tells you what} not to do; reinforcement tells you what to do

• _{What punishment often} teaches…is how to avoid it

-Skinner

• _{Today, reinforcement is a} more emphasized approach

Extending Skinner’s Understanding

• _{Even though resisted by}

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UNIT 7: LEARNING

• _{Rats seem to develop a}

cognitive map of a maze, which suggests a cognitive process

• _{Latent Learning – learning}

that becomes apparent only when there is some incentive to demonstrate it

– _{Ex: rats quickly completing a} before experienced maze when there is now food at end

• _{Excessive rewards can} undermine intrinsic

motivation (“it must not be worth doing for it’s own sake if I need to be

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UNIT 7: LEARNING

Motivation

• _{Intrinsic Motivation – a} desire to perform a

behavior effectively for its own sake

• _{Extrinsic Motivation – a} desire to perform a

behavior to receive

promised rewards or avoid threatened punishment

Motivation

• _{Giving people choices also} enhances their intrinsic motivation

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UNIT 7: LEARNING

• _{An animals natural}

predispositions constrain its capacity for operant

conditioning

• _{Biological constraints} predispose organisms to learn associations that are naturally adaptive

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UNIT 7: LEARNING

Skinner’s Legacy

• _{Skinner said external} influences (not internal thoughts and feelings) shape behavior

• _{Skinner said we should use} reward to evoke more

desirable behavior;

external consequence can help shape our future

Applications of Operant Cond.

• _{At School}

– Teaching machines that

immediately reinforce correct responses

– Students must be

immediately told whether

what they do is right or wrong and, when right, they must be directed to the step to be

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UNIT 7: LEARNING

• _{In Sports}

– Golfers start with very short putts, eventually stepping further and further away

– Batter begin with half swings at an oversized ball

– Both examples resulted in faster skill improvement

• _{At Work}

– Rewards are most likely to increase productivity if

desired performance is well-defined and achievable

– Reward specific, achievable behaviors, NOT vaguely defined merit

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UNIT 7: LEARNING

• _{At Home}

– Notice people doing

something right and affirm them for it; give children attention when they are behaving well

– When a negative behavior is observed, don’t yell or hit. Simply explain the

misbehavior and give them a time-out

• _{Self Improvement}

– State your goal

– Monitor how often you engage in your desired behavior

– Reinforce the desired behavior

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UNIT 7: LEARNING

Contrasting Classical & Operant Conditioning

• _{Similarities….}

• _{Both are forms of} associative learning

• _{Both involve acquisition,} extinction, spontaneous recovery, generalization, and discrimination

Contrasting Classical & Operant Conditioning

• _{Differences…}

• _{Classical (Pavlovian) –}

organism associates different stimuli that it doesn’t control and responds automatically (respondent behaviors)

• _{Operant – organism}

associates its operant

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UNIT 7: LEARNING

Learning by Observation

• _{Observational Learning –} learning by observing

others

• _{Modeling – the process of} observing and imitating a specific behavior

Learning by Observation

• _{Children who often} experience physical

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UNIT 7: LEARNING

Mirrors in the Brain

• _{Mirror Neurons – frontal} lobe neurons that fire when performing certain actions or when observing another doing so; may enable

imitation and empathy

• _{In children, mirror neurons} help in the development of a theory of mind

• _{Make emotions contagious}

Mirrors in the Brain

• _{“Our brain’s mirror neurons} underlie our intensely social nature.”

• _{Empathy in the brain shows} up in the emotional brain areas, but NOT in the

somatosensory cortex,

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UNIT 7: LEARNING

Bandura’s Experiments

• _{Albert Bandura – pioneering} researcher of observational learning

• _{Known for famous Bobo} Doll experiment, where children imitated the

behavior of observed adults • _{By watching, we learn to}

anticipate consequences

Applications of Observational Learning • _{We look and we learn}

• _{Behavior modeling helps} train communications,

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UNIT 7: LEARNING

Prosocial Effects

• _{Prosocial – positive, helpful} behavior

– Read with your children

– If you want them to follow a religion, practice with them – Make actions and words

consistent

– Children learn by being told what to do, and watching what we do

Antisocial Effects

• _{Antisocial – negative,} non-helpful behavior

– Abusive parents may have aggressive children

– Lessons learned as children are NOT easily unlearned as adults

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UNIT 7: LEARNING

• _{Late 20}th_{Century statistics}

on watching T.V.

– Average child viewed 8000 TV murders, 100,000 acts of

violence before finishing elementary school

– 60% of shows had violence – 74% of violence in show went

unpunished

– 58% didn’t show victim’s pain – “Violence viewing effect”

• _{Correlational studies DO} support the link between violence viewing and violent behavior

• _{Viewing cruelty to some} extent causes people to act more cruelly

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UNIT 7: LEARNING

• _{Imitation – children as} young as 14 months will

imitate acts they observe on TV

• _{Desensitized Viewers –} prolonged exposure to violence leads to viewers becoming more indifferent to it when later viewing it

• _{Watching cruelty fosters} indifference.

• _{Children often imitate pro} wrestlers

• _{Review: Ivan Pavlov,} John Watson, B.F. Skinner, Albert Bandura