PROJECT SUMMARY/ABSTRACT Visual attention, the ability to select relevant information for prioritized processing, is a fundamental mechanism for parsing a complex visual world. Importantly, attention is dynamic, acting across time to prioritize information at behaviorally relevant moments, a process known as temporal attention. Although we know that temporal attention affects visual perception, the neural mechanisms underlying temporal attention have been little investigated. Specifically, it remains unknown 1) where in the human brain temporal attention influences visual processing and 2) what cortical networks control the allocation of visual temporal attention. Here I propose to investigate the sensory and control mechanisms of temporal attention using contemporary methods in human visual neuroscience. The high spatial resolution of functional magnetic resonance imaging (fMRI) makes it an ideal tool for investigating the roles of specific cortical areas; however, its slow temporal resolution has obscured its potential value in studies of temporal attention. To circumvent this limitation, in Aim 1 I will use decoding together with a tailored experimental design to determine where in the visual cortex temporal attention modulates sensory processing. In Aim 2 I will use individual-observer mapping to identify control networks that guide temporal attention and further analyze regions of interest to distinguish between possible control mechanisms. In Aim 3 I will use the data collected in Aims 1 and 2 to test predictions of a recently introduced dynamic normalization model of temporal attention and, if warranted, update its architecture and parameters to better predict the neuroimaging data. Together these experiments and modeling will advance our understanding of the neural mechanisms of temporal attention as well as our computational theories of dynamic attention. Understanding these basic mechanisms is relevant for clinical populations with impairments in visual temporal attention, including individuals with ADHD, neglect, and cerebellar degeneration.

PROJECT NARRATIVE Visual attention is a dynamic process, influencing the sensitivity of visual perception at relevant moments in time. The proposed studies will investigate how attention to moments in time influences sensory-level processing in the visual cortex and will elucidate the neural mechanisms underlying voluntary control of attention over time. Improved understanding of these mechanisms will have clinical applications in disorders linked to attentional timing deficits such as ADHD and neglect, as well as in aging populations.