PROJECT SUMMARY / ABSTRACT Attention and arousal states play critical roles in influencing how we process information, from moment to moment. While attention is believed to be strongly coupled with arousal states, the interaction between, and independent properties of, attention and arousal in modulating visual processing remains poorly understood. In this proposed research, I will employ a combination of novel functional neuroimaging methods and computational modeling to examine how attention and arousal influence vision. Specifically, I will examine the modulatory role of attention and arousal on one of the cornerstone properties of vision, contrast sensitivity—the ability to detect an object from its background. After disentangling the independent and interactive modulatory effects of arousal and attention on contrast processing, I will build arousal into computational models of attention in order to gain insight into the potential canonical computations carried out by arousal and attention in influencing vision, which in turn has the potential to shape a wide-range of downstream processes such as memory, decision-making, and navigation. By revealing the extent and role to which attention and arousal alters early vision, results from this proposal could further our understanding of the cortical and subcortical visual function of people with abnormal arousal levels (e.g., attention deficit hyperactivity disorder, general anxiety disorder), and with potential applications down the road in guiding the diagnoses and treatment of disorders that involve atypical arousal levels.