unit 7: learning. learning is what makes us human. adaptability –ability to cope with new and...

Unit 7: Learning

Learning is what makes us human.• Adaptability

– Ability to cope with new and changing circumstances

• Does history always repeat itself? Can we change the course we’re on?

• Idea underlies all therapy

Learning is the heart of: Behaviorism• Belief that behavior is learned

– genetics has little to do with it.

• “nurture-only” belief, mainstream1960s and 70s.

• Behaviorists believed learning done through associations.– Create habits (relating behavior to expected outcomes)

• Behaviorists want psychology to be a science:– observable, testable and measurable.

Attributes of Learning

A. Learning = relatively permanent change in behavior or knowledge as a result of experience

B. Distinction between learning and performance• Performance is an exhibited behavior

• Learning can be inferred from performance, but performance is not always an accurate measure of learning

C. Learning is adaptive– Unlike most species whose behavior and bodies

have adapted to a certain environment – humans have the capacity to learn– Increase in speed of adaptation in comparison

• Learning and thinking (cognition) have allowed us to adapt to all environments on earth, without our bodies changing.

Learning IS Conditioning• Conditioning is the process of learned

associations

1. Classical – associate 2 stimuli to anticipated events

2. Operant – associate a response (behavior) and its consequence

• Repeat the good ones, avoid the bad ones3. Observational – learn from others’

experiences and link to our own associations

Classical Conditioning• Ivan Pavlov: Classical Conditioning.

http://www.youtube.com/watch?v=nE8pFWP5QDM

Pavlov (early 20th century) influenced Watson

• Watson is the father of behaviorism– Little Albert experiment

“psychology should be an objective science based on observable behavior”

• They ignored mental processes, but today we know that consciousness is important

Definitions1. Classical conditioning: learning that takes place

when originally neutral stimulus comes to produce a conditioned response because of its association with an unconditioned stimulus

• In other words – CREATING A REFLEX

2. An unconditioned stimulus (UCS or US) produces an unconditioned response (UCR or UR), even in the absence of previous training

3. A conditioned stimulus (CS) is a stimulus that has come to elicit a conditioned response (CR) because the organism associates the conditioned stimulus with the unconditioned stimulus

- Initially called the “neutral stimulus”

So let’s go back to Jaws…

Pavlov’s Classical Conditioning: Pavlovian Response or “Psychic Reflex”

• accidental psychologist: studying digestion initially

• theory links to emotion, temperament, neuroses, and language

Pavlov’s Experiment

Unconditioned vs. Conditioned Responses

• In Pavlov’s demonstration UR = CR– Salivation

• Although UR and CR consist of same behavior, there are subtle differences– CR usually weaker or less intense

• Sometimes UR and CR are different but related– Animal given a shock, UR = pain, CR = fear of

imminent pain

Conditioned Reflex

• Classically conditioned responses described as reflexes – Involuntary and automatic

Taste aversions?

Trials• How long does it take to learn something?

Classical Conditioning Applications

1. Conditioned Fear and Anxiety

• Phobias• Irrational fear due to

classical conditioning• Fear of dentist drill

• Careful though – susceptibility of irrational fear is mostly based on genetics… how?

Common Fears based on association

2. Emotional Responses– Arousal

• Smell of first love’s cologne/perfume

3. Physiological Responses• Sexual arousal in quails

– Conditioned to become aroused by nonsexual stimuli

– Conditioned to elicit increased sperm release– Fetishes for inanimate objects

• Difficult to test connections to human sexual fetishes

What’s up, girl?

Nah, it’s cool, I’m going to

chill with my boot… what’s

up, girl?

Acquisition: initial stage of learning something1. Involves repeated pairings of the CS and the

UCS/US

Acquisition Paradigms (patterns)

• What are the different ways in which the initial learning can take place?

a. Trace Conditioning– CS is presented and terminated BEFORE presentation of the

UCS/US– Conditioning often effective when the interval BETWEEN

presentation of the CS – the UCS/US is about a half second– Fear studies; dependent on usage of hippocampus– http://www.youtube.com/watch?v=PsGjh6ul7mE

b. Delay Conditioning– when CS is presented and continues at least until the

UCS/US is presented– Often times paired with trace conditioning in studies– Hippocampus-independent– Fear expression

Fear Expression in Rats

c. Simultaneous Conditioning– Occurs when CS and the UCS/US are presented

and terminated at the same time– Anti-smoking ads

d. Backward conditioning – Occurs when the UCS/US is presented before the

CS– http://www.youtube.com/watch?v=fT6IWAIf580

e. Temporal conditioning– Occurs when CS is at a fixed period of time

between presentations of the UCS/US• i.e. dog starts to salivate at 7:59am because s/he is fed

at 8am everyday

Extinction

1. A procedure that leads to gradual weakening and eventual disappearance of CR

• Involves repeatedly presenting CS without pairing it with UCS/US

Spontaneous Recovery

1. Occurs when previously extinguished CR suddenly reappears after a period of training

2. Renewal effect• response will reappear if animal is returned to original

environment where acquisition took place• Proves that extinction is a suppression not an erasure

(unlearning)• Explains drug abuse and relapse and difficulty getting rid of

phobias permanently

Classical Conditioning II

A. Generalization1. CR occurs to stimuli similar to

the CS• even though these stimuli may

have never been associated with the UCS

2. The more similar the stimuli are to the CS, the greater likelihood of generalization

– Ex: Pavlov’s dogs salivating at a different tone than in training

John Watson and Generalization

• Little Albert– sight of white rat (CS) was paired with loud noise

(UCS) until the CS alone produced crying and other responses indicative of fear

• Ethical issues with Little Albert– Never heard from again– Failure to ensure no lasting ill effects

B. Discrimination

1. stimuli similar to the CS does not produce a CR

2. The less similar new stimuli are to the original CS, the greater the likelihood of discrimination

• What happens to generalization gradient when an organism learns a discrimination?

How are discrimination and generalization similar? Different?

Higher-Order Conditioning

1. A CS functions as if it were a UCS

• Result: classical conditioning does not depend on natural US (remember the sexy quails?)

I love you, girl… almost

as much as I love that

boot

Higher-Order Conditioning

E. Factors that Affect Conditioning

1. Contiguity: The closer two stimuli are in space and time, the stronger the association between them.

-------------------------------------------------------------------2. “Belongingness”: The “fit” between CS and US

3. Contingency: “Information value.” The higher the correlation between two stimuli, the stronger the conditioned response.

4. Salience: More intense or noticeable stimuli condition more rapidly.

1. Contiguity model• Argues conditioning will occur whenever CS and

UCS are paired• Based on Pavlov

2. CS-US belongingness: not all CS’s and US’ associable

3. Contingency model• Argues CS must reliably predict UCS for

conditioning to occur– based on work of Rescorla and Wagner (took in-

depth look at each trial of conditioning)– Supported by phenomena like blocking (Kamin)

• Multiple CS tests, results?

Contingency Phenomena

• US pre-exposure effect: Presenting the US repeatedly prior to CS-US trials slows acquisition.

• CS pre-exposure effect: Presenting the CS repeatedly prior to CS-US trials retards acquisition. (a.k.a. Latent Inhibition)

Leon Kamin: Blocking

• US has to be “surprising” for association to occur– Selective attention and learning

4. Salience effects

• Overshadowing – in compound or higher order conditioning, the more salient CS wins

One last one… d’oh

• Test devaluation: critical period when stimulus/response has occurred too much, creating an adverse effect

In Conclusion!!

2 models1. Contiguity

• Conditioning will occur when CS and UCS are paired

2. Contingency • CS must reliably predict UCS for conditioning to occur

(there are a lot of things that could get in the way of that)