Pavlov's Experiment and Discovery of Conditioned Reflex

Aim of Pavlov's Experiment

• Objective: To discover what causes saliva to flow in dogs.
• Method: Re-routing saliva ducts to the outside of the dog's cheek for collection and measurement.

Initial Observations

• Hypothesis: Salivation might be a result of a fixed nervous reflex, similar to a knee-jerk reflex.
• Findings: Confirmed that dogs automatically drooled when their tongues touched food.
  • Term: Called this response the "salivation reflex."

Challenges Encountered

• Anticipation Issue: Dogs began to anticipate food and filled their cheek tubes before Pavlov could stimulate them.
• Learning: Dogs were learning to anticipate food based on experimental routine familiarity.

Introduction of New Technique

• Modifications: Erected screens to prevent dogs from seeing the experimental setup.
• Unrelated Stimulus Introduction: Utilized a ticking metronome unrelated to feeding.
  • Observation: Initially, dogs salivated only when food appeared.
  • Conditioning: After multiple trials, dogs associated ticking with food arrival.

Discovery of Conditioned Reflex

• Outcome: Dogs eventually drooled at the sound of the metronome alone, as much as they did at the food itself.
• Term: Pavlov called this the "conditioned reflex."

Broader Implications

• Conclusion: Pavlov believed this demonstrated how animals learn, even in natural settings.