A Cognitive Behavioral And ERP Study Of Decision-making In Moral Dilemma

Our decision-making may be influenced by many factors, since we live in a complex social environment. In some cases, it is not easy to make a decision when face two options diverging from each other. We may be in a difficult position to assess the potential outcome leading by decision-making. In some complicated situation, some important decisions may be dilemmas for us. Morality is an important aspect in human society, and our decision-making may be related to moral issues. In the thesis, the studies of moral decision-making mainly focus on two aspects:harm and fairness, since they are two important parts in moral domain. Moreover, one’s moral sense might be shaped by specific culture and individuals from different societies may view ethical issues differently, therefore, cultural factors should be taken into consideration in the investigation of moral decision-making. In the present dissertation, we explored the differences of moral-personal dilemmas and non-moral dilemmas on the performances of subsequent tasks by cognitive behavioral experiments. By using Event-Related Potential (ERP) technique, we further investigated the impacts of cultural factors on the electrophysiological effects of decision-making under moral dilemmas. The main contents of the thesis are as follows.1. Moral-personal dilemmas and non-moral dilemmas differently impair the subsequent performance of executive control and risk decision-making. As assessed by the Multi-Source Interference Task (MSIT) and Iowa Gambling Task (IGT), we compared the performance differences of executive control and risk decision-making following the two different decision-making tasks, respectively. The results showed a worse performance of MSIT for participants making moral-personal judgments than those making non-moral ones. And relative to the non-moral group, the moral-personal group tended to make more disadvantage choices in the second stage of IGT. The results implied that moral-personal dilemmas are more difficult and may consume more resource for executive control and decision-making, which may lead to worse performance in the subsequent executive control and risk decision-making tasks.2. Cultural differences in moral decision-making. The neural correlates of cultural differences in moral decision-making between Chinese and Westerners were investigated by combining the Event-Related Potential (ERP) technique with standardized Low-resolution brain Electromagnetic Tomography (sLORETA) analyses. Results showed that the ERP components were significantly different between the two cultural groups. Westerners elicited P2and P3components, while Chinese elicited P260components when making moral judgments. Different from the sources of P2and P3components that mainly localized in cingulate gyrus and medial frontal areas, the P260component mainly activated areas in posterior cingulate, parahippocampal gyrus, cuneus and precuneus cortices. These findings suggest a relatively earlier initiation of moral decision-making process for Westerners and a relatively integrated processing during the solution of moral decision-making for Chinese.3. Racial group membership on distributive justice. ERPs were recorded while participants made their decisions about donation allocation. Results showed that racial in-group factor influenced participants’ decision on justice consideration, and lead more in-group biased decisions. Participants were more likely to make relatively equity decisions, when racial in-group factor was congruent with equity compared to the corresponding incongruent condition. Scalp ERP analyses revealed that greater P3and late positive potential (LPP) amplitudes were elicited by the condition that racial in-group factor and equity conflicted with each other compared to the congruent condition. These findings suggest that the decision-making of distributive justice could be modulated by racial group membership, and greater attentional resources or cognitive efforts are required when racial in-group factor and equity conflict with each other.