Jason Mattingley "ICON 2014 Keynote: Eye Movements and Visual Stability"
Humans, like many animals, use eye movements to selectively sample the visual environment, bringing objects of interest onto the fovea for fine-grained analysis. Each time a saccade is made, the retinal image is abruptly displaced. The challenge for the visual system is to maintain perceptual stability in the face of such displacements. One way in which stability might be achieved is by using information about the direction and extent of an impending saccade to update internal representations of the locations and features of objects in the visual world. Neurons at various levels of the visual system, including the midbrain, parietal and prefrontal cortices, alter their responses if an impending saccade will bring a stimulus into their receptive field. Such changes in neural activity provide a potential mechanism for ensuring visual stability across saccades. In this talk I will discuss work in which we have examined the contribution of parietal cortex to visual updating across saccades. I will also present results from a series of psychophysical studies showing that object perception in peripheral vision is enhanced at the goal of an intended saccade, and that presaccadic updating preserves the elementary features of objects at their predicted postsaccadic locations. Our findings suggest a mechanism by which object recognition might be enhanced in the periphery during active search of visually cluttered environments.