learning

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 events that occur in sequence

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 announce the presence of food


• 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

– Example: checking if there is electric in a cattle fence

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

• “Behaviorism” – shaped N.

American psychology during first half of 20 th century


• 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:

• Stimulus = Loud Noise

• Response = Flinching


• Unconditioned Stimulus (US) – a stimulus that unconditionally

(naturally and automatically) triggers a response

– Ex: food 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

• Unconditioned Response (UR)

– the unlearned, naturally occurring response to a US

– Ex: salivation when food is in mouth

• Conditioned Response (CR) – the learned response to a previously neutral (but now conditioned) stimulus (CS)

– Ex: salivation to sound of a tone

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 conditioned response; in operant conditioning, the strengthening of a reinforced response

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

– Ex. – when a tone predicts food and a light precedes the tone, animal may learn that the light predicts food and respond to light

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

– Ex. – dog knows difference between bell and tuning fork

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

– The more predictable the association, the stronger CR; animal learns expectancy

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

– Thought rats may have linked plastic-tasting water (CS) to the sickness (UR) triggered by radiation (US)


• 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

– Learning enables animals to adapt to their environments

(taste aversions help animals to survive)

Pavlov’s Legacy

• By today’s standards,

Pavlov’s ideas were correct, but incomplete

Pavlov’s Legacy

• Pavlov showed us how a process such as learning can be studied objectively

• Relevance today: classical conditioning is one way that virtually ALL organisms learn to adapt to their environment

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


Conditioning

• 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 conditioned


Conditioning

• “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


Conditioning

• Watson ended up marrying

Raynor and he worked for

Maxwell House coffee, helping to introduce the

“coffee break” as an

American custom

• Man who feared elevators cured his fear by making himself take elevators 20 times per day (conditioning)

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.”

-John B. Watson


• 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 rewarding or punishing stimuli

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”

– Such a box contains an animal and has a bar or key to press or peck to release a reward of food or water; it also has a device that records responses

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 eventually gets attention

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


• 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

• Negative reinforcement removes a “punishing” event


• 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

– When a light signals food is coming, the rat will work to turn on the light


• 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 acquisition, but greater resistance to extinction

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 behavior; this will make the behavior persist


• 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


• 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

– Produces slow, steady responding

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

• Increased patrols that ensured the swiftness of punishment lead to a drop in crime rate

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

4. Physical punishment may increase aggressiveness by modeling aggression as a way to cope with problems

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

Skinner, cognitive processes have a necessary place in science of psychology


Understanding

• 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


Understanding

• Excessive rewards can undermine intrinsic motivation (“it must not be worth doing for it’s own sake if I need to be rewarded for it”)

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

• Rewards can be effective to signal a job well done; NOT to bribe or control


• An animals natural predispositions constrain its capacity for operant conditioning

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


• Instinctive Drift – when animals revert to their biologically predisposed patterns

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 taken next


• 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 welldefined and achievable

– Reward specific, achievable behaviors, NOT vaguely defined merit

– Reinforcement should be immediate


• 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

– Reduce the rewards gradually

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 behaviors with consequences

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 punishment tend to display more aggression

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, which receives the physical pain input

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, sales, and customer service skills

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, nonhelpful behavior

– Abusive parents may have aggressive children

– Lessons learned as children are NOT easily unlearned as adults

– On average, a 75 year old person in U.S. has spent 9 years watching T.V.


• 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

• “Violence on television does lead to aggressive behavior by children”


• 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

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