For their daily visual activities, humans critically rely on the foveola, the tiny high-acuity region of the retina. Vision is severely impaired when the foveola is damaged. Surprisingly little is known about foveal vision, despite its being so disproportionately important for normal functioning. The goal of this project is to understand how humans control visual attention to efficiently process fine spatial details in the foveola. If specific impairments in foveal vision can be traced back to dysfunctional strategies in the exploration of details because of poor control of attention and/or altered eye movements, it suggests new strategies for counteracting these deficits.
The specific goals of this research are: (1) To determine the spatial resolution of attention by investigating whether attention can be selectively allocated within the foveola, facilitating processing at the attended location; 2) To characterize the relationship between eye movements and attention shifts at the foveal scale by examining whether microscopic shifts of attention precede the execution of microsaccades in the same way that macroscopic attentional shifts precede normal saccades; and 3) To explore the extent to which oculomotor behavior at the microscopic scale is driven by top-down factors contributing to the creation of a "foveal saliency map," which prioritizes certain foveal locations over others. To achieve these goals, the investigator will use a state-of-the-art system for gaze-contingent control of stimulus presentation, which enables visual stimuli to be precisely displayed and maintained at desired eccentricities within the foveola.
