Identifying the function of peripheral vision in early and late scene processing

Abstract

The vast majority of visual information is located in the peripheral visual field. Our understanding of the functionality of peripheral vision is limited. This thesis investigates the function of peripheral vision during scene viewing and contrasts its role with that of the central visual field. We first establish that peripheral vision is sufficient for affective impressions of stimuli presented for brief periods of time (Experiment 1). In that study, participants perceive natural scenes presented in the peripheral vision field for as little as 50 ms to be more pleasant and interesting than urban scenes. We also contrast performance on evaluating scene gist and forming affective impressions during peripheral presentation of scenes and find that with a peripheral scene presentation of 50 ms, performance in identifying scene gist is reliably above chance. In a follow-up study, we contrast performance on scene gist between central and peripheral vision by simultaneously presenting conflicting scenes to the two visual fields. Participants were likely to rely on peripheral information to rapidly identify scene gist. In our third study, we contrast eye movements during scene viewing limited to the central, peripheral, or full visual field. We compare whether central and peripheral vision are associated with focal or ambient visual processes. Focal vision involves detailed processing of specific features in the environment, while ambient vision processes the locations of stimuli, detecting movement, and facilitating navigation (Trevarthen, 1968). We find that central vision primarily involves focal eye movements, while peripheral vision primarily involves ambient eye movements but also has a role in focal processing during late scene viewing. This work establishes that peripheral vision plays a substantial role in early and late affective processing of scenes.