Classical Conditioning

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Classical Conditioning

• Learning About the Relations between Stimuli

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Classical (Pavlovian) Conditioning

• A procedure in which learning occurs with respect
  to one event as the result of the presentation of
  two events in a defined temporal relationship.
  This procedure was first used by Ivan Pavlov.

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Ivan Pavlovs Discovery
1904 Nobel Prize for Physiology Award for his
studies of reflexes in the digestive system,
using fistulas to see activity of glands in whole
organism during normal behavior 1900 Pavlov
became interested in psychic secretion
1849-1936
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Reflexive and Psychic Secretion

• Reflexive Secretion
• Dog salivates when food is placed in its mouth
• Psychic Secretion
• Dog salivates before food is placed in its mouth,
  as though it anticipates the food delivery

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Pavlovs Analysis

• Focus on identifiable events
• Systematically vary the relationship between the
  events
• Show that behavior is explained by the history of
  stimulus presentations

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Pavlovs Training

• Present sound gt no salivation
• Present food gt salivation
• Present sound followed by food
• gt no salivation to sound, followed by salivation
  to food
• Repeat sound/food pairings
• Present sound gt salivation

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Classical ConditioningTerminology

• Unconditioned Stimulus (US or UCS)
• stimulus that elicits a response in the absence
  of explicit prior training
• Conditioned Stimulus (CS)
• stimulus that comes to elicit a response as a
  consequence of pairing with US
• Unconditioned Response (UR or UCR)
• response to the US
• Conditioned Response (CR)
• response to the CS, developed with training

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An Example Little Albert

• Little Albert was not afraid of rats and rabbits
  until John Watson and Rosalie Raynor gave him
  paired presentations of a rat and a sudden loud
  sound that scared him.
• US Loud Noise
• CS Sight of White Rat
• UR Distress, Fear
• CR Distress, Fear

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Classical ConditioningGenerality

• Salivary conditioning
• Eyeblink conditioning
• Emotional conditioning
• CER
• Autoshaping
• Flavor aversion conditioning (Garcia effect)
• Sexual conditioning

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Simple Training Schedules

• Acquisition
• CS presented in combination with US
• Reinforced CS or CS
• Extinction
• CS presented in absence of US, after acquisition
• Nonreinforced CS or CS-

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Basic Phenomena

• Acquisition
• Repeated CS trials lead to appearance of CR
• Extinction
• After acquisition, CS- trials lead to loss of CR
• Spontaneous Recovery
• After extinction, the passage of time leads to
  reappearance of CR

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Temporal Relations

• Delay Conditioning
• Trace Conditioning
• Simultaneous Conditioning
• Backward Conditioning

CS
US
CS
US
CS
US
CS
US
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Which Works Best?

• Procedures in which the CS precedes the US are
  called forward conditioning.
• Forward conditioning works better (in general)
  than simultaneous, and simultaneous works better
  than backward
• Delay conditioning works better than trace
  conditioning
• Conditioning depends on the ISI

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The ISI Function

• The interval between the onset of the CS and the
  onset of the US is called the interstimulus
  interval or ISI
• Conditioning is generally best at an intermediate
  value of ISI
• in eyeblink conditioning, the best ISI is around
  .20 seconds
• in CER conditioning, the best ISI is around a
  minute or so

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Conditioning Protocols

• Excitatory First-Order Conditioning
• CSa gt US
• Discriminative Conditioning
• CSa gt US , CSb gt No US
• Inhibitory Conditioning
• CSa gt US , CSa CSb gt No US
• Sensory Preconditioning
• CSa gt CSb , CSb gt US Test CSa
• Excitatory Second-Order Conditioning
• CSb gt US , CSa gt CSb Test CSa

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Compound Conditioning Protocols

• Facilitation
• CSa CSb gt US, CSa gt no US
• Blocking
• CSa gt US CSa CSb gt US
• Overshadowing
• CSa CSb gt US compared to CSa gt US

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General Terminology

• Events (E)
• Outcomes (0)
• Classical Conditioning
• E1 gt E2
• Organism comes to respond to E1 as a signal for E2