Classical Conditioning - Acquisition, Extinction, and Spontaneous Recovery
Time Course of Classical Conditioning
Acquisition Phase (Training Phase)
Definition: The process of pairing the conditioned stimulus (CS) with an unconditioned stimulus (UCS), which allows the CS to elicit a conditioned response (CR).
Not all temporal pairings produce classical conditioning.
Novel or intense stimuli are more likely to become conditioned than routine or less intense stimuli.
Temporal Relationships Between UCS and CS
Simultaneous Conditioning
The UCS and CS begin and end together.
Example: Bell is rung at the same time as food is delivered.
Forward Conditioning
The CS begins just before the UCS is delivered.
Example: Bell is rung just before food is delivered.
Maximal conditioning occurs in this relationship because it allows the organism to predict and prepare for outcomes.
Backward Conditioning
The UCS begins just before the CS.
Example: Food is given before the bell is rung.
Predictive utility is limited, which can result in a prolonged acquisition phase.
Extinction
Definition: If the UCS is not presented, the CS will gradually lose its ability to elicit a CR.
The time it takes to extinguish a CR depends on the strength of the conditioned bond; stronger bonds take longer to extinguish.
Extinction allows for flexibility and adaptation to changing situations.
Extinction is defined as the weakening of the conditioned response when the conditioned stimulus is present without the unconditioned stimulus.
Extinction is a learned inhibition of responding, not an unlearning of the CR.
Implications for Phobias
Behavioral treatment for phobias is based on extinction.
Spontaneous Recovery
Definition: Relapse can occur if there is a long enough break before the feared stimulus is encountered again.
Example: Successfully extinguished fear of spiders, but a spider lands on your face and you run from the house screaming.
After a break, the CR will be shown upon another presentation of the CS.
The size of spontaneous recovery response is typically smaller than it was before extinction.
The longer the delay, the larger the spontaneous recovery.
Renewal Effect
Definition: The CR is extinguished in an environment different from the acquisition environment, and the extinguished response reappears when the animal is returned to the acquisition environment.
Practical Implication: Treating a phobia in a clinic may not guarantee the person won't show the original response in their own environment (e.g., garden).
It may be beneficial to treat phobias in the appropriate acquisition environment.