title: Surround facilitation for rapid motion perception.
abstract: Because we live in a dynamic environment with moving eyes and body, our retinas are often stimulated by new scenes that appear suddenly and are only briefly available. How the visual system successfully extracts information from such challenging stimulation is not yet understood. For some stimuli, like photos of natural scenes, we are accurate in detecting objects like animals or faces even when the stimulus is presented for a short time. For other stimuli, like noisy motion, previous studies have shown accurate perception only when the stimulus is presented for a long time--often longer than the typical available time of a stimulus in natural viewing. Here we show, however, that a transient surround can accelerate the perception of motion. We found that for briefly displayed random-dots, the signal necessary to detect motion is reduced from 19% to 8% when a task-irrelevant surround is presented in synchrony with the random-dots, while no improvement occurs when the surround is sustainedly presented, or when it is transiently, but asynchronously, presented. We also found that motion sensitivity increases steadily with duration when no surround is presented, confirming previous findings, but duration has little effect on sensitivity when a synchronous surround is presented. Further results indicate that the facilitation by a synchronous surround is related to relative-motion processing. Our findings suggest that spatial interactions might assist rapid perception of motion.
authors.affiliation: Human Information Science Laboratory,NTT Communication Science Laboratories, Nippon Telegraph and Telephone Corporation, Atsugi, Kanagawa, Japan. danilinares@gmail.com
authors.forename: Daniel
authors.initials: D
authors.lastname: Linares
authors.forename: Isamu
authors.initials: I
authors.lastname: Motoyoshi
authors.forename: Shin'ya
authors.initials: S
authors.lastname: Nishida
mesh_terms: D006801:Humans; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods*; D014793:Visual Cortex / Q000502:physiology*