Changes in response time after anodal tDCS preconditioning over the human orbitofrontal cortex and emotional stimulation in moral decision making

Morality is a multidimensional phenomenon that includes cognitive and affective processes and affects social issues (as the resolution of conflicts between individual interests and the optimization of mutual benefit). For long time, research on moral judgment have emphasized the role of reason in the formulation of moral judgment [Fig.1], while more recently it has been given wide coverage and emphasis to the role of emotions [Fig.2]. Several neuroscientific studies have highlighted the importance of emotions in moral judgment: using the typical moral dilemmas it has been possible to analyze how these dilemmas entailed a different emotional involvement on people, and how these affect the moral judgment. In several studies it was shown that in the famous “Trolley” dilemma (impersonal) the majority of the participants answer in a utilitarian way, maximizing the utility of sacrificing one person to save five [Fig.4]. On the contrary, in the “Footbridge” dilemma (personal), people respond in a non-utilitarian way, claiming not to be willing to sacrifice one person in order to save five [Fig.5]. Greene et al. (2001) argued that personal moral dilemmas elicit negative emotional repsonses that induce individual to consider the action as not appropriate. In order to judge a personal moral dillemma as appropriate, the decision maker should go beyond the emotional reaction using a sort of “cognitive control” that would allow him to respond in a utilitarian way, considering the moral violation as acceptable if is for a greater good [Fig.3]. Moreover, cognitive control allows to find a justification to the action. In addition to the variable personal vs. impersonal, we have identified other variables that can influence the frequency of utilitarian and non-utilitarian responses: presence vs. absence of physical contact, action vs. omission and deliberate action vs. not intentional action. fMRI studies have shown that utilitarian and non-utilitarian reasoning are supported by different brain circuits. The non-utilitarian reasoning is mediated by automatic emotional responses, related to the activation of the OFC, while utilitarian reasoning is mediated by activation of the DLPFC, linked to cognitive processes.