Nai-Shing Yen, PhD
Professor, National Chenchi University
Talk Title: Adding new knowledge of neural underpinnings for old but important issues in social science
Abstract: Thanks to functional magnetic resonance imaging (fMRI), issues in social science could be re‐visited by investigating the underpinned neural mechanisms. In this talk I will present three projects. The first two are economic games in the context of social interactions, which are ultimatum game (UG) and trust game (TG). The third project focuses in the phenomenon called hindsight bias (HB), particularly in the social events like political elections. In UG, we modified the original UG in which proposers had to choose between a fair and a selfish offer with different share and stake sizes. This experimental design allowed us to test the two long‐debated hypotheses of fair offer behavior, namely strategic and fair considerations. Proposers showed lower rates and took longer to choose fair offer paired with slightly than extremely selfish offer. Meanwhile, they showed higher activations in mPFC (mostly dACC) representing higher requirement of cognitive control for a conflicting dilemma: a slightly selfish offer was more lucrative but somehow acceptable even though it was riskier than a fair offer. Proposers did not change the rate of fair offers with higher stakes. However, they took longer and were more active in reward‐ and theory‐of‐mind‐circuits, representing the deliberation of recipients’ answers. Finally, proposers were more activated in the dopaminergic pathway and bilateral AIC, signaling the higher expected reward and risk in slightly selfish than fair offers. In summary, our findings broadly corroborated the strategy hypothesis for making fair proposals in UG. In TG, participants (investor) could choose to invest (“trust”) their partner or not (“keep”) in the first round and their partner would reply with either a “reciprocate” or “defect” feedback decision. Participants were informed that they would play the game with partners with the same, a different or no political identity. Participants showed higher probability of trust decisions when a partner shared the same political identity, suggesting that political identities indeed modulate their cooperative decisions. They showed higher activations in the AIC (emotional processing), the TPJ (mentalizing), and the DLPFC (self‐regulatory control and/or working memory) when a partner with the same political identity defected contrasting to reciprocating their trust. In contrast, they showed greater activation in the striatum (reward learning) when a partner with a different political identity reciprocated than defecting their trust. Moreover, increased AIC activation correlated to closer perceived social distances between participants and their partners. These findings provide the first evidence on the neural foundations for the modulation effects of political identities upon trust behaviors, and indicate that studies of decision making should account for the role of social identity in altering behavior and brain response. In HB, we asked participants to predict the vote distributions of the candidates before the election. After the election, we asked them to recall their prediction by offering them the information of actual vote distributions. Result revealed that participants had HB for approximately 40% of the electoral events, which induced stronger brain activities in their bilateral IFG and mSFG. Moreover, the percentage of HB positively correlated with the intensity of left IFG and mSFG. These results were consistent with the previous findings that investigated people’s information updating behavior for general events (Sharot et al., 2011). In conclusion, our projects provide nice examples of how to apply fMRI to social sciences and how findings at the neural level can tell us new knowledge in the old but important issues.
About: Nai-Shing Yen, Professor at Department of Psychology in National Chengchi University (NCCU) in Taiwan. She obtained her Master and Ph.D in University of Texas at Arlington in USA. She was the former Chair of Department of Psychology (2007/8-2011/7), Vice President of College of Science (2011/8-2015/7), Director of Research Center for Mind, Brain, and Learning (2012/8-2015/7) at NCCU, the Board Member of Society for Neuroeconomics (2009/9-2012/9), and the President of Taiwan Psychological Association (2013-2014). Her research is in the area of cognitive neuroscience. She is currently interested in behavioral and neural mechanisms of decision making, and emotion processing.