Stimulus control of Pavlovian facilitation

Area of Science:

• Comparative Psychology
• Behavioral Neuroscience
• Animal Learning

Background:

• Autoshaping procedures in pigeons are used to study associative learning.
• Feature-positive discrimination involves a stimulus (B) that signals the availability of reinforcement when paired with another stimulus (A).
• Dimensional stimulus control refers to how stimuli varying along a continuum affect behavior.

Purpose of the Study:

• To investigate if Pavlovian facilitators exert stimulus control similar to operant discriminative stimuli.
• To compare generalization gradients resulting from facilitation training versus operant discrimination training.

Main Methods:

• Two experiments utilized an autoshaping procedure with pigeons.
• Facilitation training involved a feature-positive discrimination (A followed by grain only if preceded by B).
• Generalization testing involved varying line orientation, with and without an explicit feature-negative stimulus (B-).

Main Results:

• Generalization testing along the line-orientation dimension produced decremental gradients.
• These decremental gradients were observed when the facilitation paradigm included an explicit feature-negative stimulus.
• The observed control paralleled decremental control seen after operant discrimination training.

Conclusions:

• Pavlovian facilitators and instrumental discriminative stimuli appear to be functionally equivalent.
• This functional equivalence suggests shared underlying mechanisms for stimulus control in different learning paradigms.