Despite their importance, processes that govern affect and behavior are sensitive to disruption. This is evident at a clinical level where internalizing and externalizing psychopathologies show dysregulation in inhibition of anxious/depressive symptoms and impulsive-antagonistic behaviors, respectively (Liotti et al,2007; Moadab et al,2010). Healthy participants show similar dysregulation when highly arousing stimulus characteristics detrimentally impact performance in cognitively-demanding tasks (López-Martín, Carretié, 2010). This suggests that cognitive and affective networks draw on similar neural structures wherein more demands on one causes a change in the other (Pessoa, 2008; Vuilleumier, 2005; Ochsner & Gross, 2005). This dissertation framed the intricate and complex pattern of brain activity within the framework of a dual-layer self-regulation mechanism defined by action and affect. This model of self-regulation results in behavioral tendencies that are related either to approaching a desired outcome or avoiding an unpleasant event. An emotionally evocative task manipulation was designed to induce changes in endogenous affect and interfere with cognitive processes. An additional exogenous affect manipulation was embedding within this task through the use of salient facial expressions as stimuli. Due to the implicit aversiveness of this paradigm a separate task was used to create a scenario where participants are driven toward a desired goal. Electrophysiology methods were used to record brain activity which was analyzed using traditional ERP analysis, time-frequency decomposition, beamforming source estimation, power spectrum, and Partial-Least Squares analysis. Results implicate approach and avoidance tendencies to predict brain activity and be differentially related to delta, theta, and alpha oscillations. Theta processes related to the central executive network and map onto action, delta processes related to salience and affective networks and map onto affect, while alpha processes related to both saliency and executive control networks (i.e. the interaction between cognition and emotion) and map onto both action and affect loops. This body of work was able to address three main categories of research questions: 1) the effect of endogenous and exogenous emotion manipulations and their relationship with approach and avoidance; 2) the dynamics and impact of ongoing emotional experience; and 3) the 5-dimensional role of oscillatory changes in response to endogenous affective manipulation.
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Thesis advisor: Liotti, Mario
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