The Impact of Emotional Information on Attention and Decision-making in the Human Brain

• Main Author: Martino, Benedetto De
• Published: University College London (University of London) 2008
• Subjects: 612.8
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.504588

Emotional information is widely acknowledged to playa role in shaping human behavior. In particular emotions, by modulating attentional capacity, provide an evolutionary advantage by facilitating quick responses to potential threat. By contrast the impact of emotions on the decision-making processes is often seen as engendering suboptimal or even so-called 'irrational' decisions In this thesis I combine innovative experimental paradigms with functional magnetic resonance imaging (fMRI) and behavioral pharmacological manipulations to explore how at neurobiological level these processes share similar mechanisms. In doing so I aim to attempt a reconciliation of the aforementioned contrasting views on emotion. I examined four key aspects of interaction between emotion and both attention and decision-making: firstly, I investigated how the human brain is able to process emotional stimuli in conditions of iimited attentional resources whilst subjects were engaged in an attentional blink paradigm. Secondly, using a similar paradigm and three different drug manipulations I examined the role of noradrenaline in modulating this process. Thirdly, I have studied how the human brain processes contextual emotional information when choice options are presented. Finally I extend my research to study how during economics transactions (in which the contextual emotional information is rooted in the subjects own role as either seller or buyer) an item's value representation in the brain affects the decision process. I conclude that my results provide neurobiological support for theoretical accounts on how emotions plays a critical role in modulating complex cognitive capacity such as attention and decision-making. Specifically, the findings suggest that the increased detection of emotional stimuli under attentionalload is mediated by a frontal top-down control mechanism. The findings also show how phasiC release of noradrenaline plays a crucial role in mediating this ability. My stUdies also provide empirical evidence that an amygdala-based emotional system is responsible for a bias in decision-making showing that the integration of emotional and analytic information is expressed in orbital and medial frontal cortex enabling the subjects to resist the bias. Finally, I show that a discrepancy in item evaluation during economic transaction is encoded in the ventral striatum. My overall findings enable a specification of the biological mechanisms by which emotions modulate and shape human attention and decision-making and point, under certain experimental situations, to shared mechanisms.