Maintaining visual stability in naturalistic scenes: The roles of trans-saccadic memory and default assumptions

Abstract

How is visual stability maintained across saccades? One theory poses the visual system has an underlying assumption that the visual world has not changed during the saccade, and scrutinization of trans-saccadic memory occurs only when there is strong evidence against external stability. As support, prior studies demonstrated a “blanking effect”, where sensitivity to trans-saccadic change is increased when a short blank is inserted immediately after saccade onset. However, there remains a considerable gap between these findings, discovered with simple visual stimuli, and understanding trans-saccadic stability for rich naturalistic scenes. Here we tested human observers in a blanking paradigm with naturalistic scene images, using artificial intelligence (AI)-generated “scene wheel” stimuli that varied in a continuous and quantifiably controlled manner. Psychometric modeling revealed that inserting a brief blank screen during a saccade increased sensitivity to trans-saccadic scene changes and decreased the stability bias. These effects occurred only when observers made actual eye movements, but not when eye movements were simulated with retinal image shifts. These findings demonstrate that trans-saccadic memory of complex scenes and an overarching stability assumption work in tandem to achieve stable perceptual experience in natural environments.