The Attraction Effect Modulates Reward Prediction Errors and Intertemporal Choices.

Area of Science:

• Neuroscience
• Cognitive Science
• Behavioral Economics

Background:

• Classical economic theory assumes utility is independent of other options.
• The attraction effect demonstrates that introducing a new option can alter preferences between existing ones.
• This violates the independence of irrelevant alternatives principle.

Purpose of the Study:

• To investigate if the attraction effect impacts intertemporal choices and reward prediction errors (RPE).
• To determine if decisions and RPEs in the absence of choice violate the independence principle.
• To explore the neural and behavioral valuation of outcomes under the attraction effect.

Main Methods:

• Human participants completed an intertemporal lottery task.
• Functional magnetic resonance imaging (fMRI) was used to measure brain activity.
• Behavioral satisfaction ratings and RPE signals in the nucleus accumbens were analyzed.

Main Results:

• Intertemporal decision-making was susceptible to the attraction effect.
• Behavioral satisfaction ratings were systematically modulated by the attraction effect.
• Modulation of satisfaction ratings correlated with changes in RPE signals in the nucleus accumbens.
• Standard discounting models failed to explain the attraction effect, suggesting sequential sampling models may be more appropriate.

Conclusions:

• The attraction effect modulates subjective valuation even without explicit choice.
• Neuroscientific utility measurements may not be context-free.
• Findings challenge reinforcement learning and delay discounting theories.