The Extrafoveal Preview Effect is More Pronounced Where Perception is Poor.

Even though visual sensitivity degrades with farther distance from fovea, we make use of peripheral information to monitor or preview the surroundings, for instance, when driving (pedestrians at eye level, instrument panel at the lower visual field, farther things in the upper visual field). When we make saccadic eye movements to foveate relevant items, the peripheral information "previewed" before the saccade supports post-saccadic vision. Because our vision differs around the visual field -at the same eccentricity it is best along the horizontal, worst at the upper vertical meridian- investigating whether peripheral information at different polar angles equally facilitates post-saccadic perception has implications for everyday life. Our study reveals that peripheral preview exerts a larger influence on subsequent foveal processing at locations where vision is worse. This finding suggests that the visual system actively compensates for differences in peripheral vision when integrating information across eye movements.