Molar versus local reinforcement probability as determinants of stimulus value

Area of Science:

• Behavioral Psychology
• Animal Cognition
• Operant Conditioning

Background:

• Studies on choice behavior often assume that obtained reinforcement probability solely dictates preference.
• Previous research has primarily focused on how reinforcement outcomes influence subsequent choices.

Purpose of the Study:

• To investigate whether the scheduled rate of reinforcement influences preference independently of obtained reinforcement.
• To determine if the mere availability of choice alternatives affects preference, even without direct interaction.

Main Methods:

• Pigeons were trained on discrete-trial concurrent variable-interval schedules with differing reinforcement rates.
• Probe trials assessed preference by pairing alternatives with a constant option.
• A second group experienced alternatives individually with reinforcement distributions mirroring choice patterns.

Main Results:

• Preference was determined by the scheduled rate of reinforcement when choice was available.
• When alternatives were presented individually, preference was determined by obtained probabilities of reinforcement.
• The presence of an unchosen alternative influenced preference for the chosen alternative.

Conclusions:

• Scheduled reinforcement rates significantly impact choice preference, especially when alternatives are concurrently available.
• The availability of choice, irrespective of response, modulates preference, suggesting limitations in models solely based on obtained reinforcement.
• Current models of choice behavior, such as melioration, may be insufficient as they do not account for the influence of unchosen alternatives.