Seeing emotions in others: Improving cognitive and neuronal mechanisms of facial expression processing

In the conceptual framework of affective neuroscience, this thesis intends to advance the understanding of the plasticity mechanisms of other’s emotional facial expression representations. Chapter 1 outlines a description of the neurophysiological bases of Hebbian plasticity, reviews influential studies that adopted paired associative stimulation procedures, and introduces new lines of research where the impact of cortico-cortical paired associative stimulation protocols on higher order cognitive functions is investigated. The experiments in Chapter 2 aimed to test the modulatory influence of a perceptual-motor training, based on the execution of emotional expressions, on the subsequent emotion intensity judgements of others’ high (i.e., full visible) and low-intensity (i.e., masked) emotional expressions. As a result of the training-induced learning, participants showed a significant congruence effect, as indicated by relatively higher expression intensity ratings for the same emotion as the one that was previously trained. Interestingly, although judged as overall less emotionally intense, surgical facemasks did not prevent the emotion-specific effects of the training to occur, suggesting that covering the lower part of other’s face do not interact with the training-induced congruence effect. In Chapter 3 it was implemented a transcranial magnetic stimulation study targeting neural pathways involving re-entrant input from higher order brain regions into lower levels of the visual processing hierarchy. We focused on cortical visual networks within the temporo-occipital stream underpinning the processing of emotional faces and susceptible to plastic adaptations. Importantly, we tested the plasticity-induced effects in a state dependent manner, by administering ccPAS while presenting different facial expressions yet afferent to a specific emotion. Results indicated that the discrimination accuracy of emotion-specific expressions is enhanced following the ccPAS treatment, suggesting that a multi-coil TMS intervention might represent a suitable tool to drive brain remodeling at a neural network level, and consequently influence a specific behavior.

Emotions in legal decisions: the construction of objective narratives in Italian criminal trials

Drawing on ethnographic data collected in Italian courts and prosecution offices, this dissertation offers new perspectives on legal decision-making by highlighting the importance of emotions for constructing and evaluating legal narratives. Focusing on criminal cases, it describes and dissects how judges and prosecutors use emotions in reflection and action tied to lay narratives and legal constraints. The analysis shows that legal professionals engage in different types of emotional dynamics when dealing with stories; first, they develop gut feelings, which are either endorsed or kept at distance by means of emotional reflexivity, to comply with legal ideals of objectivity and impartiality. Second, empathy emerges as a crucial tool to direct the interaction with lay people and to interpret legal prerequisites, such as credibility, and intent. Finally, the dissertation shows that lay stories lead legal professionals to become passionate and committed towards the correct application of the law, the restoration of the moral order, and the achievement of justice. In light of the empirical findings, this thesis strives to develop a theoretical understanding of legal decision-making as narrative work that includes emotional dynamics consistent with rational, objective action.