14812 learning

LearningStimulus: Event that activates the behaviourResponse: Observable reaction to a stimuli

Define Learning

Learning is a relatively permanent change in behavior as a result of experience.

Classical Conditioning

In classical conditioning(Learning), we learn to associate two stimuli and anticipate events.

Cont…. Respondents: Automatic responses elicited by

specific stimuli. Neutral stimulus: stimulus not connected to a

response. Unconditioned stimulus: stimulus that

automatically produces an emotional or physiological response.

Unconditioned Response: Naturally occurringemotional or physiological response.

Cont….. Conditioned Stimulus: Stimulus that evokes an

emotional or physiological response after conditioning.

Conditioned Response: Learned response to a previously neutral stimulus.

Generalisation: Responding in the same way to similar stimuli.

Discrimination:Responding differently to similar but not identical stimuli.

Extinction: Gradual disappearence of a learned response.

For example, we learn that a flash of lightening signals an impending crack of thunder, so we start to brace ourselves when lightening flashes nearby.

Two related events:

Lightning

Stimulus 1

Thunder

Stimulus 2

Result after repetition

We see lightning

Stimulus

We wince anticipatingthunder

Response

Operant Conditioning In operant conditioning, we

learn to associate a response and its consequence, and we repeat acts followed by rewards, and avoid acts followed by punishment.

For example, we learn that when we get good grades, we get money, so we continue to get good grades. Or, if we don’t get good grades, we lose privileges. To avoid losing privileges, we get good grades.

Social/Vicarious/Observational Learning

In social learning (or observational learning), we learn from other’s experiences and examples.

For example, chimpanzees sometimes learn behaviors merely by observing others perform them. If one animal watches another learn to solve a puzzle that gains a food reward, the observing animal may perform the trick as well, and even more quickly.


Classical Conditioning Ivan Pavlov - Russian;

Medical doctor who spent two decades studying the digestive system. Nobel Prize in 1904. Studied learning for the next three decades, by “accident”.

Classical Conditioning After studying salivary secretion in dogs, he

knew that when he put food in a dog’s mouth the animal would invariably salivate. He also began to notice that when he worked with the same dog repeatedly, the dog began salivating to stimuli associated with food – the sight of food, the food dish, the mere presence of the person bringing the food, even the sound of oncoming footsteps in anticipation of the food

Classical Conditioning Pavlov’s Experiment: Through experimentation, Pavlov asked: If

a neutral stimulus (something the dog could see or hear) regularly signaled the arrival of food, would the dog associate the two stimuli (the food and the neutral stimuli)? If so, would the dog begin to salivate to the neutral stimulus in anticipation of the food?

From Pavlov’s research:


Unconditioned StimulusA stimulus that naturally

and automatically triggers a response

Classical ConditioningUnconditioned Response

The unlearned, naturally occurring response to the unconditioned stimulus


For example:For Pavlov, the UCS was

food and the UCR was the dog’s salivation

Classical Conditioning Pavlov’s Experiment (continued): Just before placing food in the dog’s

mouth to produce salivation, Pavlov sounded a tone. After several pairings of tone and food, the dog began to salivate to the tone alone, in anticipation of the food.

Classical Conditioning Conditioned Stimulus

An originally irrelevant stimulus that, after association with and unconditioned stimulus, comes to trigger a conditioned response

Classical ConditioningConditioned Response

The learned response to a previously neutral conditioned stimulus

Classical Conditioning For example:

For Pavlov, the previously neutral stimulus was the tone. During conditioning, the tone was paired with the food (UCS). After conditioning, the tone, when presented alone, produced salivation in the dog. The tone is now considered the CS, and the dog’s salivation to the tone alone is now considered the CR.

UCS(drug)

UCR(nausea)

CS(waiting room)

CS(waitingroom) CR

(nausea)

UCS(drug)

UCR(nausea)

1. While George was having a cavity filled by his dentist, the drill hit a nerve that had not been dulled by anesthetic, a couple of times. Each time he cringed in pain. George now gets anxious each time he sees the dentist.

What is the: Unconditioned stimulus: ____________________ Unconditioned response: ____________________ Conditioned stimulus: ____________________ Conditioned response: ____________________

You ride a roller coaster and get sick afterward. Now, whenever you are near a roller coaster you feel queasy.

Your relationship is going badly and your significant other has yelled at you without warning several times. You now feel tense and fearful any time that you are around him or her.

Four Major Conditioning Processes

Generalization Discrimination Extinction Spontaneous Recovery

Acquisition The initial stage in classical

conditioning The phase associating a neutral

stimulus with an unconditioned stimulus so that the neutral stimulus comes to elicit a conditioned response

Acquisition Findings:

The time between presenting the neutral stimulus and the unconditioned stimulus needs to be short. For most species and procedures, about ½ second works best.

Conditioning is more likely to occur if the conditioned stimulus is presented before the unconditioned stimulus

Generalization The tendency, once a response has been

conditioned, for stimuli similar to the conditioned stimulus to elicit similar responses IE. A dog responding to a bell tone may

also respond to a similar sounding door bell.

Discrimination The learned ability to distinguish

between a conditioned stimulus and other stimuli that do not signal an unconditioned response IE. A child is bitten by a dog, and only

fears that dog. Other dogs don’t illicit an automatic fear response.

Extinction The diminishing of a conditioned

response when an unconditioned stimulus no longer follows a conditioned stimulus If the food no longer follows the bell tone,

eventually the dog will no longer associate the bell tone with food and will stop salivating.

Spontaneous Recovery The reappearance, after a rest period,

of an extinguished conditioned response.

The conditioned response continues to get weaker after less pairings of the CS and the UCS, and after more and more rest periods

Classical Conditioning – Extra Little Albert Experiment – Fear Conditioning

An 11-month infant named Albert feared loud noises, but not white rats. In the experiment, when Albert was presented with a white rat and reached out to touch it, a hammer was struck on a steel beam behind his head. After seven repetitions of seeing the rat and then hearing the frightening noise, Albert burst into tears at the mere sight of the rat.

Classical Conditioning - Extra Five days after the testing, Albert

showed generalization of his conditioned response by reacting with fear to a rabbit, a dog, and a sealskin coat.

The Effect of motives: Motive effects the conditioned response.The dog was hungry so associated bell with food.

Time factor between two stimuli: there should be less gap in time between two stimuli to evoke a conditioned response and percieve the relation between two stimuli.

Repetition of the stimuli:This is done for association of neutral stimulus with UCS

Operant Conditioning

Operant: voluntary behaviour emitted by an organism

Operant conditioning : learning in which voluntary behaviour is strenthened or weakened by antecedents(EVENTS BEFORE ACTION) or consequences(EVENTS AFTER ACTION)

Operant Conditioning Type of learning in which

behavior is strengthened if followed by a reinforcer, or diminished if followed by a punisher

Operant Conditioning B.F. Skinner’s Experiments:

Based on Edward Thorndike’s LAW OF EFFECT – states that rewarded behavior is likely to recur

Experiments conducted with animals in an operant chamber (Skinner Box) – a soundproof box, with a bar or key that an animal presses or pecks to release a reward of food or water

Operant Conditioning Shaping – while conditioning

an animal to perform certain behaviors, reinforcers are successively given only as the subject gets closer to the ultimate behavior goal

IE. If the purpose of putting a rat in a maze is to teach it to get from Point A to Point B while following a certain path, then every time the rat makes a turn towards the right path, a reward should be given. If it makes a turn towards the wrong path, NO reward is given.

Operant Conditioning If we can shape animals to

respond to one stimulus and not to another, then obviously they can perceive the differences.

IE. Some pigeons have been trained to be able to distinguish between Bach and Stravinsky.

IE. If the goal of a teacher is to get all students to strive for 100% accuracy on their spelling tests, then every time a student improves on successive spelling tests they should be rewarded. NOT just reward those that get a 100%.

Operant Conditioning Reinforcement – any event

that increases the frequency of a preceding response, or strengthens the behavior that it follows

IE. Being able to borrow the car after the dishes are done will increase the likelihood that you will do the dishes again.

Operant Conditioning Positive Reinforcement –

strengthens a response by presenting a typically pleasurable stimulus after a response. IE. Food for a hungry animal.

Attention, approval, money for people.

Operant ConditioningNegative Reinforcement –

strengthens a response by reducing or removing an aversive stimulus

IE. Taking aspirin to relieve a headache will increase the behavior of taking aspirin because it reduces or eliminates the pain. Smoking a cigarette to relieve stress will increase the behavior of smoking because it reduces or eliminates anxiety and pressure.

Operant Conditioning Positive ADDS a desirable stimulus,

like getting a hug or watching t.v. Negative REMOVES an aversive

stimulus, like fastening a seatbelt to stop the annoying beeping

Operant Conditioning Primary Reinforcers –one that

primarily satisfies a biological need

Conditioned or Secondary Reinforcers – a stimulus that is learned, and/or is associated with a primary reinforcer

IE. Primary reinforcers may be food, or pain relief. Secondary reinforcers may be money, praise, good grades, a pleasant tone of voice.

Operant Conditioning Immediate and Delayed Reinforcers –

How quickly does a reinforcement needed to be given after a desired behavior has been exhibited in order for the behavior to be conditioned? How often does the reinforcement need to be given to condition proper behavior?

Operant Conditioning Continuous Reinforcement –

Reinforcing the desired response immediately, every time it occurs. Learning occurs quickly, but as soon as reinforcement ends, extinction occurs very quickly also.

You go to the same soda machine every day, put your money into it, and it delivers a soda. On Friday, you put your money into it and it doesn’t work. Same thing Saturday. You stop using the machine, though a week later you may try again.

Operant Conditioning Partial (Intermittent)

Reinforcement – Reinforcing a response only part of the time. This results in slower acquisition of a response, but much greater resistance to extinction also.

IE. Slot machines. You may win only once in long while, but you’ll keep playing because the reinforcement is worth it, and the habit may last a long time.

Operant Conditioning Partial (Intermittent) Reinforcement

Schedules: Fixed-Ratio = a schedule of

reinforcement that reinforces only after a specified number of responses. IE. Every 10th sale gets a prize.


Schedules: Variable-Ratio Schedule = a

schedule of reinforcement that reinforces a response after an unpredictable number of responses IE. Slot machines, fishing.


Schedules: Fixed-interval schedules = a schedule

of reinforcement that reinforces a response only after a specified time has elapsed IE. At the end of every 30 minutes a

new batch of cookies will be baked.

Operant Conditioning Partial (Intermittent) Reinforcement Schedules:

Variable-Interval Schedules = a schedule of reinforcement that reinforces a response at unpredictable time intervals IE. “You’ve Got Mail”…you don’t

know when you will get an email, but you are always checking for it.

Operant Conditioning Punishment – An event that

decreases the behavior that it follows May be done by administering an

undesirable consequence, or by withdrawing a desirable consequence

IE. Shock treatment and spanking are added, undesirable consequences, while taking away phone or car privileges withdraws desirable consequences.

Operant Conditioning Issues/Questions regarding punishments

Physical punishments are not forgotten, just suppressed

Physical punishments may increase aggressiveness by demonstrating that aggression is a way to cope with problems

Punishments may create fear

Operant Conditioning If punishment isn’t delivered swiftly,

or proportionally with regards to the crime, those punished may be confused, depressed, or helpless

Punishments still do not teach the proper behavior – it only suppresses unwanted behaviors

Observational Learning


Observational Learning is learning by watching and imitating others

Observational LearningFor example, a child sees

his big sister burn her fingers on the stove has thereby learned not to touch it.


Modeling is the process of observing and imitating a specific behavior

Observational LearningPro-Social Models exemplify

positive, constructive, helpful behavior. Anti-Social Models exemplify negative and hurtful behavior.

Observational LearningMirror Neurons in the

frontal lobe are partially responsible for allowing humans to imitate simple language and emotions

Observational Learning Albert Bandura’s Experiment – The

Bobo Doll Children exposed to an adult taking

out their frustrations on a Bobo doll would imitate their punches and kicks when presented with a Bobo doll when they were frustrated.

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14812 learning