Distinct Roles of Central and Peripheral Vision in Rapid Scene Understanding

Abstract

Central and peripheral vision loss, caused by conditions such as age-related macular degeneration and retinitis pigmentosa, disrupt visual processing in distinct ways, yet their impact on natural scene perception remains poorly understood. Here, we used a real-time, gaze-contingent simulation to examine how central vision loss and peripheral vision loss alter eye movements and scene understanding. Sighted participants (n = 32, 5 males) viewed 120 natural scenes under one- or three-saccade constraints and described each scene; description quality was quantified via semantic similarity to ground-truth responses. Peripheral vision loss observers produced significantly less informative descriptions than both central vision loss and control participants, particularly for social interaction scenes, suggesting that peripheral vision is critical for rapid extraction of scene semantics. In contrast, central vision loss primarily disrupted oculomotor behavior, including increased saccade amplitudes, delayed saccade initiation, and reduced inter-subject fixation consistency. Description quality was not predicted by fixation similarity to controls, but by fixations to annotated humans and critical objects, underscoring the role of semantically informative sampling. These results reveal a dissociation between perceptual and oculomotor consequences of vision loss and highlight the neural importance of peripheral input for natural scene understanding. Significance statementUnderstanding how vision loss affects real-world perception requires disentangling the distinct contributions of central and peripheral vision. Using gaze-contingent simulations of biologically plausible scotomas, we show that peripheral vision loss degrades scene understanding more severely than central loss, particularly for socially meaningful content. In contrast, central vision loss led to more pronounced changes in eye movement planning, including larger and delayed saccades. These findings reveal a dissociation between perceptual and oculomotor consequences of visual field loss, suggesting that peripheral input plays a critical role in rapid semantic processing of natural scenes. Our results underscore the importance of evaluating functional vision using ecologically valid tasks and could inform future strategies in low vision rehabilitation.