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Lecture Notes
Chapter 5

Change in behaviour through experience

Distinguish from:

• Fatigue
• Satiation
• Maturation, etc.

Decreased response to unimportant stimulus

Short- and long-term habituation

Examples:

• Clock
• Startle reaction in rat

Doesn't last too long

Evolutionary reason?

Temporary return of habituated response

• Decrease release of neurotransmitters
• At presynaptic axon terminal
• Fewer action sites
• Also fewer neurotransmitter vescicles involved

Habituation

• Trained as physiologist
• Studied digestion
• Role of salivation

• Food in mouth
• Saliva in vial
• Experienced dogs salivated before food in mouth

• Unconditioned stimulus (UCS)
  • e.g., food
• Unconditioned response (UCR)
  • e.g., salivation
• Conditioned stimulus (CS) 
  • e.g., tone
• Conditioned response
  • e.g., salivation

• Innate, automatic
• Like reflex arc

• Learned
• Originally CS neutral and no CR produced

Short-delay

• Most used, most effective
• CS is predictive of US

Long-delay

• Not quite as good
• Distractors, other stimuli

Backwards

• Not usually effective
• CS not predictive of UCS

Spontaneous Recovery

• Time dependent
• Temporary return of CR after extinction

• Inhibitory CS-

• Discrimination

• Novel food = CS; illness = UCS

Garcia and Koelling (1966)

• Biological predispositions
• Can't condition any CS to any UCS

• Edward Thorndike
• Cat in puzzle box
  • Discrete trials
• A good outcome strengthens the response that produced it (and a bad outcome weakens the response that produced it)

• Invented by B.F. Skinner
• Continuous trials
• Cumulative recorder

Discriminative Stimuli

• Stimulus that sets the occasion for responding
• Can have more than one at the same time

• Reinforcer: increases a behaviour
• Punisher: decreases a behaviour

• Positive: a stimulus is presented
• Negative: a stimulus is taken away

• 

• Extinction
• Forgetting

• Successive approximations
• Training new behavioural responses
• Gradual steps

• Continuous reinforcement (CRF)
• Fixed ratio (FR)
• Fixed interval (FI)
• Variable ratio (VR)
• Variable interval (VI)

• Record can only go up or flat

Extinction

• Intermittent schedules
  • FR, VR, FI, VI
  • Hard
• Continuous schedules
  • CRF (i.e., FR1)
  • Easier
• Extinction burst

• Generalization
  • Stimuli similar to discriminative stimulus can elicit response
• Discrimination
  • Can distinguish similar stimuli from the discriminative stimulus; won't respond
• Herrnstein and Loveland (1964)
  • Discrimination training with pigeons

• Primary: biologically significant
• Conditioned (secondary): acquire reinforcing properties through association with primary conditioners

• Escape: ends an aversive stimulus
  • Negative reinforcement
• Avoidance: prevents an aversive stimulus from being presented
  • Negative reinforcement

• Solomon and Wynne (1953)
  • Dog, chamber with barrier
  • Shock, light off as discriminative stimulus

Learned Helplessness