Learning and Conditioning

Simple learning

• Habituation
  • repeated stimulation → ↓ response
• Sensitization
• repeated stimulation → ↑ response

Classical conditioning

• Reflexive response normally elicited by an unconditioned stimulus becomes evocable by a second, conditioned stimulus 
• Pavlov’s dogs are the typical example of classical conditioning
  • ringing a bell provoked salivation
    • natural response = salivation
    • conditioned stimulus = bell
    • unconditioned stimulus = food
• Extinction occurs when the conditioned stimulus is no longer associated with the unconditioned stimulus.
• over time the response will no longer be elicited 

Operant conditioning

• Type of learning in which reward elicits action
• Positive reinforcement
  • desired reward produces action
  • e.g. mouse presses button to get food
• Negative reinforcement
  • removal of aversive stimulus elicits behavior
  • e.g. mouse presses button to avoid shock
• Punishment
  • aversive stimulus prevents unwanted behavior
• Extinction
• discontinuation of reinforcement eliminates behavior

Reinforcement schedules

• Pattern of reinforcement determines how quickly a behavior is learned or extinguished
• Continuous
  • reward received after every response
  • rapidly extinguished
  • think “vending machine”
• Variable ratio
  • reward received after random number of responses
  • slowly extinguished
  • think “slot machine”