How Prior Decisions Influence Future Choices in Decision Making

New Model More Accurately Describes Decision-Making Under Uncertainty

Researchers from the University of Tsukuba have developed a new model, known as “dynamic prospect theory,” which integrates two influential theories in behavioral economics and neuroscience to more accurately portray human and monkey decision-making under uncertainty.

Integrating Two Decision-Making Theories

The new approach combines two popular models: prospect theory, which describes decision-making under risk, and reinforcement learning theory, which describes learning for decision-making.

To test its accuracy, the research team recruited 70 participants and asked them to choose between two lotteries that varied in reward size, probability, and risks.

Surprising Outcomes

The findings revealed an intriguing pattern: after experiencing an outcome larger than the expected value of their chosen option, participants behaved as though the probability of winning the next round increased. While they were clearly told the winning probabilities, this did not seem to impact their behavior.

The team went one step further and tested the model on the behavior of macaque monkeys, whose brains are similar to ours. Again, the researchers observed the same behavior in the monkeys, highlighting the remarkable similarity in human and monkey decision-making.

Change in Perception of Probabilities

What was driving the change in behavior? According to Senior Author, Assistant Professor Hiroshi Yamada, it was a perception of probabilities and not a change in rewards’ valuation. Yamada also noted that this type of learning operates in reinforcement learning theory when people learn rewards from experience.

Implications for Future Research

The similarity of the results observed in monkeys and humans could mean that the study of monkey brains might lead to a better understanding of the brain mechanisms involved in risk-taking and reward perception.

In conclusion, the “dynamic prospect theory” model presents a more comprehensive theoretical framework that could be used to explore a neurobiological model of economic choice in primates.

Key Facts:

– The “dynamic prospect theory” model integrates prospect theory and reinforcement learning theory.
– Participants and monkeys demonstrated increased probability perception after experiencing an unexpected outcome.
– Change in behavior is related to a change in the perception of probability and not the valuation of rewards.