台大心理系

Decisions are prone to bias. This can be seen in daily choices. For instance, when the markets are plunging, investors tend to sell stocks instead of purchasing them with lower prices because in general potential losses lure more than the potential gains. Bias also can be seen in laboratory tests. After participants receive higher payoffs for successfully discriminating a visual stimulus as one choice against the other, they begin choosing this higher-rewarded option more often even though the objective evidence indicates the alternative. In my talk, I will present two studies that I used mathematical models and functional magnetic resonance imaging (fMRI) to track the development of bias in perceptual and financial decision-making and presented evidence characterizing the experience-sensitive and domain-general decision-making process in the human brains. The first study shows that bias could be developed through associating decision contexts and reward feedback from trial to trial in perceptual decision-making. Although the surface task differed, this learning process involved the same prediction error driven mechanisms implemented in the dopaminergic system as in economic decision-making. Furthermore, the frontal cortex increased its strength of connection between visual and value systems that accounted for the growth of perceptual bias. The second study extends this feedback-driven acquisition process to examine the influences of experience on loss aversion in financial decision-making. The results showed that people learned to make riskier or more conservative decisions according to the feedback that they had received in different decision contexts. This alternation in loss aversion was achieved through gauging the value system’s sensitivity toward the potential gains that was mediated by the frontal cortex. These findings not only integrated the knowledge in different domains of decision neuroscience but also shed lights onto how one may refine the decision-making process against experiences.