COORDINATE TRANSFORMATION IN AFTEREFFECTS AND ATTENTION

后遗症和注意力的协调转变

• 批准号: 6498229
• 负责人: SHINSUKE SHIMOJO
• 金额: $ 22.9万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-02-01 至 2004-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6498229
• 关键词: attention; body movement; clinical research; cues; eye movements; head movements; human subject; proprioception /kinesthesia; saccades; smooth pursuit eye movement; space perception; visual pathways; visual perception

Visual scenes do not appear to shift when an eye movement causes the optical image to move across the retina, but do when the same retinal displacement occurs while the eyes are stationary. How does the visual system achieve this "position constancy" during eye movements? The goal of this project is to understand the coordinate transformations which enable position constancy by generating a body- or environment-centered description of objects from their eye-centered representation. Instead of the traditional approach to this problem, measuring mislocalization of a briefly flashed dot stimulus, we will examine various types of aftereffect/cue effect, including visual aftereffects (eg. figural, and motion), visual-motor aftereffects (eg. saccade. and arm reaching) and an attention-induced motion illusion (the "shooting" line motion effect) by employing what we call the fixation/refixation paradigm. Focusing on such effects, we could investigate the coordinate transformation process which is relevant to the overall spatial context, and thus higher-order and biologically significant. The typical experiment will consist of an adapting (cueing) phase, and a testing phase to measure negative aftereffect (or strength/direction of the illusory motion). Unlike the conventional procedure, however, there will be a refixation phase between the adapting and the testing in which the fixation point will move, and the subject will be asked to make either a saccade or smooth pursuit eye movement to it before the test presentation. This manipulation enables us to isolate the adapted location in coordinate systems or maps, including the eye-centered and the non-eyecentered, i.e. the head-, the body-, and the environment-centered. By presenting the test stimulus at various locations, we will obtain a spatial tuning curve of the effect and apply a cross-correlation. analysis to find out the degree to which the visual system maintains the eye-centered representation, and/or transfers it into a non-eye-centered description. If we find a significant non-eye-centered component, as indicated by our pilot studies, we will determine exactly which non-eye-centered system (head-, body-, or environment-centered) is relevant by rotating the observer's head and/or torso in a vestibular chair. We will further compare active and passive head/body turn conditions to identify the nature of extraretinal signals on head position which contribute to this transformation process. The results will bridge the gap between animal physiology and human psychophysics, and provide insights into-the processes underlying coordinate transformations.

当眼球运动导致光学图像在视网膜上移动时，视觉场景似乎不会发生移动，但当眼睛静止时发生相同的视网膜位移时，视觉场景似乎会发生移动。视觉系统如何在眼球运动过程中实现这种“位置恒定性”？该项目的目标是理解坐标变换，通过从以眼睛为中心的表示生成以身体或环境为中心的对象描述来实现位置恒定。我们将检查各种类型的后效/提示效应，包括视觉后效（例如图形和运动）、视觉运动后效（例如眼跳），而不是采用传统的方法来测量短暂闪烁的点刺激的错误定位。通过采用我们所说的固定/再固定范式，产生注意力引起的运动错觉（“射击”线运动效果）。着眼于这些影响，我们可以研究与整体空间背景相关的坐标变换过程，从而具有更高的阶次和生物学意义。典型的实验将包括适应（提示）阶段和测量负面后果（或幻觉运动的强度/方向）的测试阶段。然而，与传统程序不同的是，在适应和测试之间会有一个重新注视阶段，其中注视点将移动，并且在测试演示之前，将要求受试者对其进行扫视或平滑的追踪眼球运动。这种操作使我们能够隔离坐标系或地图中的适应位置，包括以眼睛为中心和非以眼睛为中心的位置，即以头部、身体和环境为中心。通过在不同位置呈现测试刺激，我们将获得效果的空间调谐曲线并应用互相关。分析以找出视觉系统维持以眼睛为中心的表示的程度，和/或将其转换为非以眼睛为中心的描述。如果我们发现一个重要的非以眼睛为中心的组件，如我们的试点研究所示，我们将通过旋转观察者的头部和/或躯干放在前庭椅上。我们将进一步比较主动和被动头部/身体转动条件，以确定有助于这一转换过程的头部位置的视网膜外信号的性质。研究结果将弥合动物生理学和人类心理物理学之间的差距，并提供对坐标变换背后过程的见解。