Comparing utility functions between risky and riskless choice in rhesus monkeys

Area of Science:

• Neuroscience
• Decision Science
• Behavioral Economics

Background:

• Expected utility theory posits that choices are made to maximize subjective value (utility).
• Both risky and riskless decisions may rely on utility maximization, potentially sharing common neuronal mechanisms.
• A unified utility function for both decision types is hypothesized but not empirically confirmed.

Purpose of the Study:

• To investigate if a single utility function can describe macaque monkey behavior in both risky and riskless decision-making scenarios.
• To determine if distinct utility representations exist for different types of choices.

Main Methods:

• Elicited utility functions from two macaque monkeys performing both risky and riskless choice tasks.
• Analyzed choice behavior to derive underlying utility functions.
• Accounted for subjective probability weighting in the analysis.

Main Results:

• The utility functions derived from risky choices differed significantly from those derived from riskless choices.
• This divergence persisted even after controlling for subjective probability weighting.
• The findings reject the hypothesis of a common utility function for both decision types.

Conclusions:

• Distinct utility representations appear to underlie risky and riskless choices in primates.
• These differences may reflect separate neural substrates or computational mechanisms for processing different decision contexts.
• Future neuroscience research on utility-based choice should consider these distinct representations.