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Learning I and II

• Chemotherapy patient has anticipatory nausea, so cannot keep up her strength. How does this happen and what can be done to help it?

• Dealing with parent/children problems: Child acts up at a store. Parent ignores, then responds by yelling and grabbing child. What are consequences and how might it be handled?

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Learning UnitOverview of Class

(I) Definition of learning

(II) Biological constraints on learning

(III) Varieties of learning

(A) Habituation

(B) Classical conditioning

(C) Instrumental conditioning

(D) Classical & Instrumental conditioning

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(I) Definition of Learning

Learning - storage of information in memory as a consequence of experience

* Learning is inferred from performance

* But . . . . Learning is not equivalent to performance

** Fatigue, Motivation, Specific performance measures

Challenge of learning -- what goes with what?

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(II) Biological Constraints on Learning

(A) Fixed action patterns - innate behaviors

(B) Critical periods

(C) Stimulus/response specificity

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(II) Biological Constraints on Learning

(A) Fixed action patterns - innate behaviors

Characteristics:

* Initiated by specific stimuli

* Progress automatically once initiated

Examples:

* Grasping, sucking & head turning, respiration occlusion reflex

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(II) Biological Constraints on Learning

(A) Fixed action patterns - innate behaviors

(B) Critical periods

* Imprinting - basis for child/parent attachment

* Bird song, Language learning

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Figure 6-2 Apparatus used for the imprinting of ducklings. A duckling was givenSystematic exposure to the decoy as it moved around the runway.

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In a choice discrimination test, percent of time that ducklings chose the imprinted decoy as a function of time between birth and the imprinting experience.

Age (hours)

Hess, E. H. Imprinting. Science, 1959, 130, 133-141.Reprinted by permission of the American Associationfor the Advancement of Science.

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(C) Stimulus/Response Specificity

Early view; All stimuli have an equal chance of being associated with responses

Present view: Some S-R pairs have precedence in learning

Intervention Shock Nausea/X-rays

Conclusions: External punishment -- > external stimulus

Internal punishment -- > internal stimulus

Example: Odors & tastes associated with chemotherapy are strong cues for anticipatory vomiting

Bright/noisy waterTraining Sweet water

low

lowHIGH

HIGH

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Evidence that the consequences of responding determine the stimuli that come to control the response.

X-ray ShockRevusky, S., & Garcia, J. Learned associations over long delays. In G. H. Bower (Ed.), The psychology of learning and motivation (Vol. 4). New York: Academic Press,1970, pp. 1-84. Reprinted by permission of Academic Press, Inc.

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(III) Varieties of Learning

(A) Habituation - decreased responding to repetitive stimulus

* From single cell organism to human ………………..

* Example: Finch study

** Alternative explanations for “habituation”:

(a) Fatigue - No - “dishabituation”

Response returns if stimulus changes a little

(b) Extinction of conditioned response ….. No

Response will come back with delay

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Decline in “chink” calls emitted by chaffinches on successivedaily tests with a live owl. Each chaffinch was exposed tothe owl for 20 min. a day. The number of calls emitted byeach day was expressed as a percentage of the number on Day 1.

Daily Tests

Rel

ativ

e F

requ

ency

of

Cal

ls (

perc

ent)

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(B) Classical Conditioning Pavlov and his famous dogs ……………………..

Critical observation: Dog salivates when Pavlov enters room

Experiment: Before conditioning

UCSMeat powder

CSBuzzer

OrientingResponse

UCRSalivation

During conditioning After conditioning

CS ….. UCS UCR CSBuzzer

CRSalivation

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(a) Does the temporal relationship between the CS & UCS matter?

Forward Delayed Backward

CS CS CS UCS UCS UCS

Best Learning Worst

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(b) Is conditioning permanent?

Assumes:

CS without UCS after conditioning

* Process of Extinction

* Process of Spontaneous Recovery

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(c) Is conditioning automatic & unselective?

Animal “A” - tone conditioned

Conditioning

UCSShock

CRFear

CSTone

CSTone

Orienting

UCRFear

Test

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Animal “B” - tone and light conditioned

Conditioning

UCSShock

CRFear

CSTone

CSTone & Light Orienting

UCRFear

Test

CRFear

CSLight

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Animal “C” - tone, then tone & light -- Blocking Initial Conditioning

UCSShock

CSTone

Orienting

UCRFear

Then with same animal… second conditioning phase.

UCSShock

CSTone & Light

UCRFear

Orienting

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Animal “C” - what has the animal learned?

CRFear

CSTone

Test -- tone still conditioned to fear, but light is NOT -Initial conditioning of tone has BLOCKED it from being learned in second conditioning phase

OrientingCS

Light

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(d) Does CR become equivalent to UCR?

Early view: (Pavlov) - Yes

Recent view: CR takes whatever form is most adaptive

--- can be compensatory or opponent to UCR

An Example: Drug tolerance …… and overdose

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UCSHeroin

UCRDecreasedrespiration

An Example: Drug tolerance …… and overdose

Drug has UCR but also a rebound

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Opponent Process Theory

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Predicted Effects of Conditioning on Opponent Processes

• As can see in Panel B, as conditioning continues, the opponent process b (CR) increases in size and counteracts the UR, a

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*Drug has UCR (component a) and then rebound of increased respiration (component b -- withdrawl)*Component b malleable, gets conditioned to familiar environment, and occurs earlier so counteracting UCR.*Need higher dose to get same effect

BUT ….. When in an unfamiliar environment there is no counteracting effect and therefore possible overdose

UCSHeroin

CSFamiliar

environment

UCRDecreasedrespiration

CRIncreased

respiration

An Example: Drug tolerance …… and overdose

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Overdosing

• Two groups of mice injected with ethanol for four days in same environment

• Day 5 - given 1.5 times usual dose– Familiar environment -- 0% fatalities– New environment -- 60% fatalities

• Newer findings (Siegel, 2004)-- may also be true of internal cues to drugs

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(e) Real-world effects & applications of Classical Learning

* Phobia - unrealistic fear which develops from a frightening experience (claustrophobia)* Anxiety

* Situational Hypertension

* Systematic Desensitization - method for reducing intense anxiety by having patients visualize a graduated series of anxiety- provoking stimuli while maintaining a relaxation

CS CR

Aircraft, airport, etc. Anxiety

??????? extinction or new (calmer) response

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Here are the first fifteen scenes from a hierarchy used with a clientwho feared flying.1. You are reading the paper and notice an ad for an airline.2. You are watching a television program that shows a groups of people boarding

a plane.3. Your boss tells you that you need to make a business trip by air.4. It is two weeks before your trip, and you ask your secretary to make airline

reservations.5. You are in your bedroom, packing a suitcase for your trip.6. You are in the shower on the morning of your trip.7. You are in a tax on the way to the airport.8. You are checking in for your flight and the agent says, “Would you like a

window or aisle seat?9. You are in the waiting lounge and hear an announcement that your flight is

now ready for boarding.10. You are in line, just about to board the airplane.11. You are in your seat and hear the plane’s engines start.12. The plane begins to move as you hear the flight attendant say, “Be sure your

seatbelts are securely fastened.”13. You look at the runway as the plan waits to take off.14. You look out the window as the plane begins to roll down the runway.15. You look out the window as the plane leaves the ground.

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Chemotherapy and classical conditioning

• Become associated with tastes and odors

• Foods eaten before therapy may lead to taste-aversion, a problem for nutrition

• Distinctive food before chemotherapy can be “scapegoat” so aversion tied to that.– Children given unusual candy (coconut-flavor) with

meal before therapy

– Other foods in meal more likely to be eaten later than for group with no unusual candy

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Final remark on classical conditioning

• Many organisms show classical conditioning

• Neural bases are very different, but form is very similar

• Why? Adaptive way of responding– To survive, we have systems to anticipate and

react to common, important stimuli

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Instrumental (operant) Conditioning

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(C) Instrumental (Operant) Conditioning

Operant Behavior Reinforcer

Child eats vegetables “Barney” video

(a)Shaping - reinforcing approximations of desired behavior

* dramatically speeds-up conditioning (especially)

when behavior occurs infrequently

(b)Superstitious behavior

Operant behaviors Reinforcer

carry rabbit’s foot desired outcome consult palm reader

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(C) Instrumental (Operant) Conditioning

(c) Schedules of Reinforcement

* Fixed ratio - each n responses

- paid for each piece --> fast responses

* Variable ratio - each variable # responses

- slot machines --> hard to extinguish

* Fixed interval - after t time

-emergency room admissions in N.Y.

--> scalloped curve

* Variable interval - after variable time

- unannounced examinations --> hard to

extinguish

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Partial reinforcement

• Harder to condition behavior (since many unreinforced desired actions)

• Longer to extinguish behavior (since extinction not so different from learning -- many unreinforced desired actions)

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(d) Types of Behavior-Reinforcer Contingencies

* Positive reinforcer - something positive following behavior

* Negative reinforcer- removal of something aversive

** escape conditioning

* Punishment - administration of something aversive

Disadvantages: ** doesn’t tell you what to do

** elicits aggression & hostility To be effective:

immediate, severe, consistent, offer alternative behaviors

Learned helplessness (Seligman) - organism punished in an unpredictable manner will show impaired learning

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Learned helplessness

Group APhase 1: Shock -- escaped by pressing nose padPhase 2: Shock -- escaped by jumping over

barrier

Group BPhase 1: Shock -- same as Group A - no control

over escaping (pressing nose pad did not help)Phase 2: Shock -- could escape by jumping over

barrier, but do not -- learned helplessness

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Learned helplessness - repairing

Some evidence that if can show organism that behavior WILL influence environment, that they can get over learned helplessness.

If animals forced over barrier repeatedly, will begin to jump over it to avoid shocks.

Real-world applications

Math anxieties; clinical depressions

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What is reinforcement reinforcing?

• Learning or Performance?

• Evidence is Performance -- important to realize that organisms (people) can be learning much more than they are showing by performance – Example: Rats -- cognitive maps of routes

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(e) Applications of Instrumental Conditioning

* Programmed instruction - small units of behavior are reinforced. Gradually increase unit size.

* Behavior Modification

** Smoking cessation programs

** Weight loss programs

** Token economies in psychiatric hospitals

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(D) Classical & Instrumental Learning

Have examined separately, but

1. Many similarities in effects of practice, extinction, recovery, blocking -- classical between stimulus and stimulus, instrumental between stimulus and response (leading to reinforcer)

2. often there are mixtures of Classical & Instrumental learning

Classical conditioning - anticipatory vomiting with chemotherapy

CS / medical office CR / vomiting

IF ….. patient is distracted from CS vomiting should cease

Instrumental conditioning

Operant behavior Reinforcer

imagery/relaxation Decreased vomiting

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Concluding remarks

• Wide variety of very different events arise from conditioning

• Be aware that behaviors you see may come about in unintended ways -- useful when you are considering how to repair harmful behaviors

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Readings and key termsFadem - Ch. 7

• Fixed action patterns Habituation Critical periods, imprinting

• Classical conditioning Extinction UCR, CR, UCS, CS • Systematic desensitization Spontaneous recovery

• Operant conditioning Shaping Partial reinforcement• Fixed ratio, variable ratio, fixed interval, variable interval• Positive and negative reinforcers Punishment• Learned helplessness Behavior modification