Pan Jing Samantha, Li Jingrong, Chen Zidong, Mangiaracina Emily A, Connell Christopher S, Wu Hongyuan, Wang Xiaoye Michael, Bingham Geoffrey P, Hassan Shirin E
Department of Psychology, Sun Yat-sen University, Guangzhou, China.
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre, Sun Yat-sen University, Guangzhou, China.
J Vis. 2017 Oct 1;17(12):13. doi: 10.1167/17.12.13.
Events consist of objects in motion. When objects move, their opaque surfaces reflect light and produce both static image structure and dynamic optic flow. The static and dynamic optical information co-specify events. Patients with age-related macular degeneration (AMD) and amblyopia cannot identify static objects because of weakened image structure. However, optic flow is detectable despite blurry vision because visual motion measurement uses low spatial frequencies. When motion ceases, image structure persists and might preserve properties specified by optic flow. We tested whether optic flow and image structure interact to allow event perception with poor static vision. AMD (Experiment 1), amblyopic (Experiments 2 and 3), and normally sighted observers identified common events from either blurry (Experiments 1 and 2) or clear images (Experiment 3), when either single image frames were presented, a sequence of frames was presented with motion masks, or a sequence of frames was presented with detectable motion. Results showed that with static images, but no motion, events were not perceived well by participants other than controls in Experiment 3. However, with detectable motion, events were perceived. Immediately following this and again after five days, participants were able to identify events from the original static images. So, when image structure information is weak, optic flow compensates for it and enables event perception. Furthermore, weakened static image structure information nevertheless preserves information that was once available in optic flow. The combination is powerful and allows events to be perceived accurately and stably despite blurry vision.
事件由运动中的物体构成。当物体移动时，其不透明表面反射光线，产生静态图像结构和动态光流。静态和动态光学信息共同明确事件。年龄相关性黄斑变性（AMD）和弱视患者由于图像结构减弱而无法识别静态物体。然而，尽管视力模糊，光流仍可被检测到，因为视觉运动测量使用低空间频率。当运动停止时，图像结构持续存在，并可能保留由光流指定的属性。我们测试了光流和图像结构是否相互作用，以使在静态视力不佳的情况下仍能感知事件。AMD患者（实验1）、弱视患者（实验2和3）以及视力正常的观察者，在呈现单个图像帧、带有运动遮罩的帧序列或带有可检测运动的帧序列时，从模糊图像（实验1和2）或清晰图像（实验3）中识别常见事件。结果表明，对于静态图像且无运动时，除实验3中的对照组外，其他参与者对事件的感知不佳。然而，当存在可检测的运动时，事件能够被感知。在此之后立即以及五天后，参与者能够从原始静态图像中识别事件。因此，当图像结构信息较弱时，光流会对其进行补偿并实现事件感知。此外，减弱的静态图像结构信息仍然保留了曾经在光流中可用的信息。这种组合很强大，尽管视力模糊，仍能准确而稳定地感知事件。
