Visual learning and attention guidance in patients with macular degeneration

影响黄斑的视网膜损伤会导致高分辨率视力的丧失。患者学会使用视网膜的外围部分来代替中央凹视觉。由于视网膜周围的受体密度较低，这意味着空间分辨率的丧失。在本项目中，我们想探讨黄斑损伤是否涉及视觉选择性注意和视觉长期记忆的缺陷。从对正常视力观察者的调查中，我们了解到选择性注意和通过眼球运动探索环境之间存在密切联系。当发现因丧失中央凹固定而受损时，可能会导致注意选择的缺陷。由于对一个物体的注意选择是日后从长期记忆中提取的重要前提，黄斑损伤也可能导致视觉长期记忆的缺陷。我们打算通过内隐学习和视觉对象记忆测量视觉搜索引导的一系列实验来研究这些主题。搜索和记忆的速度和准确性将与眼动模式以及大脑激活有关。患者数据将进一步与正常视力个体的数据进行比较，在正常视力个体中，盲点将通过注视随机显示来模拟。

Retinal damage affecting the macula leads to loss of high-resolution vision. Patients learn to use peripheral parts of their retina to replace foveal vision. Because of the lesser receptor density in the retinal periphery, this means a loss of spatial resolution. In the present project, we want to explore whether macular damage entails deficits in visual selective attention and visual long-term memory. From investigations in normal-sighted observers we know of a close link between selective attention and exploration of the environment by means of eye movements. When exploration is impaired by loss of foveal fixation, deficits of attentional selection may be a consequence. Since attentional selection of an object is known to be an important precondition for later retrieval from long-term memory, macular damage may also entail deficits in visual long term memory. We intend to investigate these topics in a series of experiments in which we measure guidance of visual search by implicit learning as well as visual object memory. Speed and accuracy of search and memory will be related to eye movement patterns as well as brain activation. Patient data will further be compared to data from normal-sighted individuals, in whom scotomata will be simulated via gaze-contingent displays.