Behavioral contrast: Pavlovian effects and anticipatory contrast

Area of Science:

• Behavioral psychology
• Animal behavior research
• Learning and conditioning

Background:

• Behavioral contrast arises from Pavlovian stimulus-reinforcer relations and anticipatory contrast.
• Isolating these two sources of behavioral control is crucial for understanding complex schedules.

Purpose of the Study:

• To procedurally isolate Pavlovian stimulus-reinforcer relations and anticipatory contrast in a multiple schedule.
• To investigate how reinforcement availability and component duration influence these two sources of control.
• To determine conditions under which Pavlovian effects may be obscured in multiple schedules.

Main Methods:

• Utilized a four-ply multiple schedule with two fixed two-component sequences in pigeons.
• Manipulated differential cuing of Component 2 and reinforcement availability during target components (Experiment 1).
• Systematically varied target-component duration (Experiment 2).

Main Results:

• Pavlovian control was observed under all conditions in Experiment 1, with no anticipatory contrast.
• Pavlovian control was reliable only when target components were unreinforced and diminished with increased duration.
• Anticipatory contrast emerged when target components were reinforced.

Conclusions:

• Pavlovian stimulus-reinforcer relations exert control in multiple schedules, but this can be masked by anticipatory contrast.
• The presence and magnitude of anticipatory contrast are influenced by reinforcement schedules and component durations.
• Understanding the interplay between Pavlovian control and anticipatory contrast is key to interpreting behavior in complex schedules.