Classical Conditioning

• Classical conditioning


  The type of learning that occurs through the repeated association of two (or more) different stimuli. Learning is only said to have occurred when a particular stimulus consistently produces a response that it did not previously produce.
• Three-phase model of classical conditioning

  1. Before conditioning

  2. During conditioning

  3. After conditioning
• Key elements of classical conditioning

  • Unconditioned stimulus (UCS)
  • Unconditioned response (UCR)
  • Neutral stimulus (NS)
  • Conditioned stimulus (CS)
  • Conditioned response (CR)
• Unconditioned stimulus (UCS)


  Any stimulus that consistently produces a naturally occurring, automatic stimulus (e.g. Meat powder)
• Unconditioned response (UCR)


  The response that occurs naturally/automatically when the UCS is presented. It is a reflexive, involuntary response (e.g. The meat powder (UCS) causes salivation (UCR))
• Neutral stimulus (NS)


  Any stimulus that does not normally produce any response (e.g. a desk or a pen)
• Conditioned stimulus (CS)


  The stimulus that was 'neutral' at the start now elicits the same response that was caused by the UCS
• Conditioned response (CR)


  The learnt response that is produced by the CS. The CR occurs after the NS has been associated with the UCS and has become the CS (e.g. the salivation of the dog)
• Unconditioned means unlearnt, Conditioned means learnt
• Classical conditioning


  1. NS (neutral stimulus) does not evoke any response

  2. UCS (unconditioned stimulus) evokes an involuntary physiological response (Blinking, vomiting, fear, salivation)
• When the conditioned stimulus is presented and no physiological response is present it is called extinction
• Extinction


  The gradual decrease in the strength or rate of a CR that occurs when the UCS is no longer presented
• There is variation between individuals (animals & humans) in the rate at which extinction will occur
• Stimulus generalisation


  The tendency for another stimulus that is similar to the original CS to produce a response similar to the CR
• Stimulus discrimination


  It occurs when a person or animal responds to the CS only, but not to any other stimulus that is similar to the CS
• Spontaneous recovery


  The re-appearance of a CR when the CS is presented again after a rest period (e.g. when the UCS is not presented for a few trials and then the CR has been extinguished)