Transsaccadic Memory and Scene Representation

我们主观地把视觉世界看作是一幅由视觉细节组成的全彩色全景图。 这种经验自然导致人们相信，人类视觉系统生成了外部场景的完整和真实的内部副本，类似于详细的彩色照片。 与这种直觉一致，过去的研究表明，人类对场景的视觉记忆可以非常好。 同时，众所周知，视觉细节和丰富的色彩只有在眼睛直接指向的地方才能获得。 为了弥补这种限制，我们的眼睛在一个场景中从一个地方飞到另一个地方，这是一系列非常快速的眼球运动，称为扫视。 这些眼跳中散布着短暂的停顿，称为注视，只有在这些注视停顿期间，才能从场景中实际获取视觉信息。 因此，如果我们的视觉系统真的像经验所表明的那样，创造了一个完整的外部世界的内部表征，那么这个表征必须从每次注视时拍摄的各个快照中拼接起来。 与这种直观上吸引人的观点相反，最近有大量证据表明，人类视觉系统并没有构建这样一个高保真的世界副本。 例如，最近的一个显著发现是，人类观众通常对视觉世界中从一个时刻到下一个时刻发生的戏剧性变化非常不敏感。 这一发现表明，尽管有经验和直觉，但整个场景的摄影图像并不能同时用于与世界的当前状态进行比较。 那么，随着时间的推移，人类视觉系统产生并保留的内部表征的本质是什么？本研究的主要目的是了解人类观众在长时间内动态观察世界时产生的视觉表征。 本研究将致力于发现人类视觉感知、视觉认知和视觉记忆的基本原理。 这项研究将使用复杂的方法，结合联合收割机快速和强大的图形处理和演示系统与一个高度准确的眼动跟踪系统。 使用这些仪器，复杂的场景将在真实的时间内根据场景内的特定眼睛运动而改变，并且将在各种条件下测量视觉系统对这种变化的敏感度。 这项工作的结果将扩大我们对人类大脑如何产生感知体验和视觉引导性能的理解，并将有助于指导新的人机界面的设计。 研究结果还将有助于指导科学家构建下一代人工视觉系统。

We experience the visual world subjectively as a full-color panorama of visual detail. This experience naturally leads to the belief that the human visual system generates a complete and truthful internal copy of the outside scene, similar to a detailed color photograph. Consistent with this intuition, past research has demonstrated that human visual memory for scenes can be exceptionally good. At the same time, it is well known that visual detail and rich color are only available where the eyes are directly pointed. To compensate for this constraint, our eyes flit from place to place over a scene in a series of very fast eye movements called saccades. Interspersed among these saccades are brief pauses, called fixations, and it is only during these fixational pauses that visual information is actually acquired from the scene. Therefore, if our visual system does in fact create a complete internal representation of the external world, as experience suggests, then this representation must be stitched together from the individual snapshots taken during each fixation. In contrast to this intuitively appealing view, there is a good deal of recent evidence that the human visual system does not construct such a high-fidelity copy of the world. For example, a remarkable recent discovery is that human viewers are often very insensitive to dramatic changes in the visual world that take place from one moment to the next. This finding suggests that despite experience and intuition, a photographic image of the entire scene is not concurrently available for comparison to the current state of the world. What, then, is the nature of the internal representation that is generated and retained over time by the human visual system?The main objective of this research is to understand the visual representations that arise as the human viewer examines the world dynamically over extended time. The research will be directed toward discovering the principles that underlie human visual perception, visual cognition, and visual memory. The research will use sophisticated methods that combine fast and powerful graphics manipulation and presentation systems with a highly accurate eyetracking system. Using these instruments, complex scenes will be changed in real time contingent on a specific eye movement within the scene, and the sensitivity of the visual system to such changes will be measured under a variety of conditions. The results of this work will expand our understanding of how the human brain gives rise to perceptual experience and visually guided performance and will help guide the design of new human-computer interfaces. The results will also help guide scientists in building the next generation of artificial vision systems.