<aside> 💡 9/27: Review pages 104-110

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The Blocking Effect

• Two conditioned stimuli are employed

  Bread pudding ex:

  • Bread pudding
  • Taste of the special sauce

• Phase 1: experimental group receives repeated pairings of one of the stimuli (A) with the US

  • Continues until a strong CR develops to stimulus A

• Phase 2: stimulus B presented with stimulus A and paired with US

  • Stimulus B presented alone in a test trial to see if it elicits the CR

• Very little responding responding occurs to stimulus B even though stimulus B was repeatedly paired with the US during phase 2

• Phase 2:

  • Control group receives the same kind of conditioning trials (A+B paired with US) as the experimental group
  • In the control group, stimulus A is not conditioned prior to the stimulus-compound trials

• Stimulus B produces less conditioned responding in the experimental group than in the control group

• Initially investigated in fear conditioning; suppression technique with rats

• Geometric cues

• Control 2 group learned the correct location of Triangle B best because this learning was not blocked by another stimulus in the way
• Blocking group participants had a very low correctness when it came to Triangle B in the test (20%), Triangle A had been previously conditioned with the US before Triangle B was introduced. This illustrates blocking

<aside> 👉 Blocking effect shows that pairings of a CS and US are not enough for conditioned learning to develop

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• If US is not surprising, it will not activate the “mental effort” required for learning
• What makes something unexpected is that we don’t know enough to make good predictions about it

<aside> 👉 Learning occurs when something is surprising is a fundamental concept in learning theory

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The Rescorla-Wagner Model

• Formal mathematical equation that the effectiveness of a US is determined by how surprising it is