Interaction between emotional and cognitive systems is required for producing appropriate reactions to the environment and for enhancing sensory processes to detect useful incoming information. Individual differences in the processing of emotional stimuli, as seen in varying degrees of anxiety or anhedonia, may underlie varying subsequent behavior and top-down/bottom-up (TD/BU) control of sensory processing. An extensive body of research has focused on correlating anxiety scores with threat-related processing in a variety of affect-related areas such as the amygdala, prefrontal cortices, and basal ganglia in response to negative emotional stimuli and performance in high-order tasks of attention. However, comparatively fewer studies have investigated the relationship between hedonic capacity, neural response in reward-processing regions such as the ventral striatum and others, and with efficiency in attentional tasks. Examinations of reward-processing have focused on risk taking and addiction. It remains unclear how emotion-biased performance changes are rooted in basic perception. With this project, I will address these issues by: examining how anxiety and anhedonia affect performance on emotion-cued visual search (Aim1) and using emotional stimuli of - valence to examine effective connectivity differences between emotion processing regions and TD/BU control areas of perception (Aim2). I will contrast these effects on orientation, color, and motion direction regions (Aim3). In an event-related fMRI session, healthy participants rated for anxiety and anhedonia will perform feature (FS) and conjunction (CS) visual search, known respectively to invoke BU control alone or with additional TD control (Wolfe, 1998). A trial uses a neutral, fearful or happy face cue to evoke responses in emotion processing areas, followed by a task display to covertly search for a target based on a single (FS) or pair (CS) of features. Dynamic Causal Modeling of fMRI data will reveal effective connectivity patterns between emotion processing areas and TD/BU control of visual perception. I predict higher anxiety scores to be correlated with enhanced connectivity between fear regions and early visual regions (V1-V5) in threat-cued FS and weaker connectivity between the amygdala and TD regulatory regions (including the anterior cingulate, OFC, vm/dl PFC, PPC) during threat-cued CS. Higher anhedonia scores may correlate with stronger connectivity between reward and BU regions in reward-cued FS and weaker connectivity TD regions during positive-cued CS. I will incorporate these findings in a limbic-cortical model of emotional-biased of visual perception, which will improve understanding psychiatric illnesses like depression, whose cardinal symptoms include anxiety and diminished hedonic capacity. ? ? ?
