Development of Visual Stability in Human Infants

人类婴儿视觉稳定性的发展

• 批准号: 9108723
• 负责人: Richard Aslin
• 金额: $ 24.44万
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-08-01 至 1995-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9108723&HistoricalAwards=false
• 关键词: Development; Visual; Stability; Human; Infants

The goal of this research project is to determine at what age and with what underlying mechanism young infants perceive the visual world as stable despite movements of the eyes, head, and body. Adults perceive the visual world as stable despite self-produced movements primarily by means of reflexive eye movements triggered by visual and vestibular stimulation. These eye movements serve to reduce or eliminate those movements of the retinal image that are created by self-produced movements. The vestibulo-ocular reflex (VOR), triggered by rotations or translations of the head, counter-rolls the eyes in the direction opposite to head movement. The optokinetic reflex (OKR) moves the eyes in the direction of retinal image movement. These reflexes are supplemented by a fine-grained analysis of retinal image velocities located near the current direction of gaze and converted into eye movement signals for the smooth pursuit system. In a typical visual environment with objects at many different distances, the observer must select a depth-plane for fixation and suppress those retinal image motions created by objects at nearer and farther distances. When the visual scene moves, either because of object movement or movement of the observer, the three oculomotor systems -- VOR, OKR, and smooth pursuit -- are activated in concert to stabilize the attended object despite the movements of other retinal images. These experiments will present 2- to 6-month-old human infants either with moving visual displays while they are held in a stable head/body position or with stationary visual displays while their head/body is moved laterally. The former condition stimulates the OKR and smooth pursuit systems, while the latter condition stimulates all three systems to reveal the role of the VOR. At issue is how effectively infants are able to keep the object of attention stabilized on the retina despite movements of the visual surround and/or movements of the head/body. Based on earlier work showing that smooth pursuit does not emerge until 2 months of age and depth perception does not emerge until 4 months of age, Aslin predicts that if the smooth pursuit system is the critical factor, then effective stabilization should emerge at 2 months of age. However, if segregation of objects in depth is the critical factor, then effective stabilization should not emerge until 4 months of age. These results from normal infants will provide a baseline for understanding the development of three oculomotor systems that are known to be essential for adults' perception of a stable visual world.

这个研究项目的目标是确定婴儿在什么年龄和什么样的潜在机制下感知视觉世界是稳定的，尽管眼睛、头部和身体在运动。成人认为视觉世界是稳定的，尽管主要通过视觉和前庭刺激引发的反射性眼球运动来产生自我运动。这些眼球运动有助于减少或消除那些由自我产生的运动所产生的视网膜图像的运动。由头部旋转或平移触发的前庭眼反射（VOR）会使眼睛朝与头部运动相反的方向转动。光动力反射（OKR）使眼睛朝着视网膜图像运动的方向运动。这些反射由位于当前凝视方向附近的视网膜图像速度的细粒度分析补充，并转换为平滑追踪系统的眼动信号。在具有许多不同距离物体的典型视觉环境中，观察者必须选择一个深度平面进行固定，并抑制近距离和远距离物体产生的视网膜图像运动。当视觉场景移动时，无论是由于物体的移动还是由于观察者的移动，三个眼动系统——VOR、OKR和平滑追踪——都被协同激活，以稳定被关注的物体，而不管其他视网膜图像的移动。这些实验将向2至6个月大的人类婴儿展示头部/身体保持稳定时的移动视觉显示，或头部/身体横向移动时的静止视觉显示。前一种情况刺激了OKR和平滑追踪系统，后一种情况同时刺激了这三个系统来揭示VOR的作用。争论的焦点是，婴儿在视觉环境和/或头部/身体运动的情况下，如何有效地将注意力对象稳定在视网膜上。基于早期的研究表明，平稳的追求直到2个月大才出现，深度感知直到4个月大才出现，Aslin预测，如果平稳的追求系统是关键因素，那么有效的稳定应该在2个月大的时候出现。然而，如果物体的深度分离是关键因素，那么有效的稳定应该在4个月大之前出现。这些来自正常婴儿的结果将为理解三个动眼肌系统的发展提供基线，这些系统对于成年人对稳定视觉世界的感知至关重要。