Affective processing and executive control

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In this project, we will use functional magnetic resonance imaging (fMRI), intracranial event-related potentials (ERPs), and behavioral performance to investigate the interplay of affective and executive control processes and the brain systems that mediate their interactions. This new project reflects a synthesis of research themes developed in Projects 3 and 4 or the current grant period. It is stimulated by our observation that task-irrelevant stimuli that evoke emotional responses strongly activate brain structures comprising a ventral affective processing system (VAPS) and evoke a relative deactivation of brain structures comprising a dorsal executive control system (DECS). This relative deactivation of DECS and, in particular, dorsolateral prefrontal cortex (dIPFC) is associated with poor working memory performance. Our goal is to identify brain systems that interact to enhance or impede task performance by varying the degree to which the subject's primary task depends upon executive function and the DECS; by varying the valence and arousal properties of task-irrelevant distracters; by varying the current focus of attention; and by varying baseline levels of arousal, emotion and/or stress. There are three specific aims: Specific Aim 1 will determine (a) whether the degree of phasic dIPFC activation evoked by critical task events influences task disruption induced by emotional distracters and (b) whether the tonic state of activation influences the degree to which dorsolateral prefrontal cortex (dIPFC) shows relative deactivation by emotional distracters. Specific Aim 2 will investigate whether the VAPS can be activated by manipulating the "mental workload" of a cognitive task, and whether workload induced activation of this system can itself evoke a relative deactivation of dIPFC and other components of the DECS leading to poor task performance. The effect of noise stressors upon the engagement of DECS by working memory tasks will also be investigated in this Aim. Specific Aim 3 will investigate whether the VAPS is automatically activated by emotional distracters, or whether activation is limited by concurrent attentional demands. Changes in affect and emotional regulation are frequent and debilitating aspects of neurological disorders such as stroke, Parkinson's disease, ALS, and Alzheimer's disease. An understanding of how affective processing influences executive control will provide new insights into remediatory approaches toward these disorders and into the functioning of the normal human brain.