LEARNING

Chapter 8

What is NOT Learning?

• Reflexes

• Instincts

• Imprinting

(Konrad Lorenz)

What is Learning?

•Any relatively permanent change in behaviour potential that occurs because of experience

•We learn by association

•Conditioning - basic kind of learning

Ivan Petrovich Pavlov, 1849-1936

• Classical or Pavlovian

Conditioning

• “What the hell difference does a revolution make. . .when you’ve got work to do in the lab?”

Classical Conditioning

•Studied digestion sec

Components of Classical conditioning

•Environmental conditioning of involuntary behaviour

–Unconditioned stimulus (UCS, US)–Unconditioned response (UCR, UR)

•unconditioned = unlearned

–Conditioned stimulus (CS)–Conditioned response (CR)

Three Stages

Processes of Conditioning•Acquisition

•best learned when CS presented 1/2 sec prior to UCS

Processes of Conditioning•Extinction

Processes of Conditioning•May reappear after a rest pause

How Long Does it Take?

• John Garcia’s experiments

• The Garcia effect

The Study of Learning

•Behaviourism–approach to psychology, U.S., 20th century–led by John Watson, carried further by B.F. Skinner

–Emphasized observable behaviour, role of environment as determinant

John Broadus Watson, 1878-1958•1913 - psychology a failure

•“failed to establish itself as a natural science”

•“should be a purely objective experimental branch of natural science”

Environmental Determinism

•“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 beggarman and thief - regardless of the talents, tendencies, abilities, vocations, and race of his ancestors.”

–1925

Fear conditioning•Pairing of a NS with a fear-provoking object

–very powerful–resistant to extinction–can occur after only 1 pairing–model for phobias–Little Albert (Watson/Rayner)

Fear conditioning

Generalization vs. Discrimination

• Generalization: Responding to a similar stimulus

• Discrimination: Responding ONLY to the exact stimulus

Other applications

Instrumental Conditioning

•Edward Thorndike (1874-1949)

– The Law of Effect

“Behavior that is rewarded will be repeated”

Burrhus Frederic Skinner, 1904-1990

Radical Behaviourism

Operant Conditioning (Skinner)•Conditioning or learning of voluntary behaviors

Operant Conditioning

Operant Conditioning•Negative Reinforcement

–Escape Behavior

–Avoidant Behavior

Schedules of Reinforcement

•Continuous Reinforcement

•Partial or Intermittent Reinforcement

Continuous vs Partial Reinforcement•Partial reinforcement

–slower acquisition–more resistant to extinction–pigeon may peck a key 50 to 100 times after reinforcement has been cut off if it previously was on a schedule of continuous reinforcement –after some types of intermittent reinforcement, the bird will peck from 4000 to 10,000 times before responding extinguishes

Partial Reinforcement Effect

-parents often learn this the hard way!

Schedules of Reinforcement•Ratio = number of responses

•Interval = time elapsed

•Fixed-Ratio (FR) getting paid by the piece

•Variable-Ratio (VR) slot machines

•Fixed-Interval (FI) candy on Fridays

•Variable-Interval (VI) a realtor sells a house

Reinforcers

• Primary vs. Secondary

• Immediate vs. Delayed

Motivation

• Skinner would object!

• Extrinsic vs. Intrinsic

• Overjustification

Shaping•By successive approximations

Biological & Cognitive Constraints•Environments are not destiny!

•Skinner underestimated importance of constraints on learning

•Conditioning principles constrained by biological predispositions of each species

•“Never try to teach a pig to sing. It wastes your time and annoys the pig.” Mark Twain

Observational Learning•Bandura - Social Learning Theory

–we learn by watching what others do and what happens to them for doing it–vicarious learning–vicarious reinforcement–vicarious punishment

•Imitation: children tend to imitate adult models–classic Bobo doll study

Observational Learning

•people may learn anti-social behavior simply by observing it on tv

Observational Learning•Three major effects

–psychic numbing–increase in likelihood of aggressing–increases estimation of its occurrence

•pro-social lessons can also be learned –from tv–from models

Habituation•Orienting response – automatic shift of attention toward a new event

Learned Helplessness