Clinical Neuroscience Lab

Department of Psychology at Seoul National University​


Neuroscience of Decision-Making

Ability to make rational decisions is a fundamental component for individuals to behave adaptively in a society.  Decision-making indicates the cognitive process resulting in the selection of a course of actions among several alternative possibilities. In terms of psychopathology, pathological decision-making patterns have been observed in several mental disorders, including schizophrenia, depressive disorder, addictive behaviors, compulsive disorder, and post-traumatic stress disorder.



We examined specific components of decision making that are impaired in schizophrenia using a competitive zero-sum game program (Kim, Lee, Shin, & Chey, 2007). Schizophrenia patients showed similar patterns of choices in a noncompetitive task in which the expected payoffs of the two options were fixed and unaffected by the agent’s choice. However, in a computerized decision-making task, in which the predictable choice behavior was penalized and the optimal strategy was to choose the two targets stochastically, they were impaired in integrating the outcomes of their previous choices appropriately in order to maintain the optimal strategy.  This impairment in strategic decision making was characterized as strategic stiffness, which may have implications for the poor social adjustment in schizophrenia patients.























Fig. 1 – Layout of the decision-making task. The task of the subject was to predict whether the computer opponent would choose the front or the back of a card and to press a designated letter in a computer keyboard accordingly. After the subject's response, the sides chosen by the subject and the computer were revealed simultaneously. The subject won or lost a certain amount of money depending on whether the two sides matched and which side was chosen by the subject.



More recently, we have investigated the effect of stress on decision making at both behavioral and neural levels using computational reinforcement learning models and functional magnetic resonance imaging. We have found that stress disrupted model-based reinforcement learning and decision making. By the way, the effect of stress on decision making was not monotonic but bi-directional depending on the degree of stress (Park, Lee, Chey, 2014; Chey, Park, Lee, Daw, 2014).



Kim H, Lee D, Shin YM, Chey J (2007) Impaired strategic decision making in schizophrenia. Brain Research, 14(1180),


Park, H. (2015). The effect of stress on decision-making. (Doctoral dissertation, Seoul National University).

Park, H., Lee, D., & Chey, J. Multiple effects of stress on decision making in an changing environment. 2014 Society                  for Neuroscience Annual Meeting.