Coordinate Transformation in Aftereffects and Attention

描述（由申请人提供）：眼球运动不断地在视网膜上产生视觉图像的变化。尽管有这些动态输入，我们仍然感知到视觉世界的稳定性或恒常性。恒定性大概是基于来自视网膜和非视网膜信号的空间内部表征。该建议旨在了解大脑如何跨和单独利用不同的坐标系（表示）进行转换，哪些视网膜外信号用于调制或坐标转换过程，以及大脑的哪些区域负责这些过程。我们将应用凝视操纵范式来研究感觉运动后效，如扫视和臂伸适应，注意调节的知觉效应和反应时间，以及空间定位和记忆。我们将我们的范例扩展到使用前庭椅的头部和身体转动，并使用经颅磁刺激（TMS）来深入了解潜在的神经机制。一个典型的凝视操纵范式实验将包括一个适应（提示或目标呈现）阶段，随后是一个测试阶段，以测量负面后果、注意调制或错误定位。然而，与传统程序不同的是，在适应/提示和测试之间将有一个重新固定阶段，在这个阶段中观察者必须将目光移动到一个新的位置。这使我们能够在以眼睛为中心和非以眼睛为中心，即以头部、身体和环境为中心的参考坐标框架中分离出适应/提示位置。通过在不同的位置呈现测试刺激，我们将得到一个空间调谐曲线，以找出视觉系统维持以眼为中心的表征和/或将其转移到非以眼为中心的描述的程度。如果我们发现凝视相关的调制或非以眼为中心的成分，正如我们的试点研究表明的那样，我们将通过在前庭椅上旋转观察者的头部和/或躯干，准确地确定哪个非以眼为中心的系统（头部、身体或环境为中心）是相关的，以及哪些视网膜外信号是关键的。我们将进一步将TMS应用于执行注意力提示任务的观察者的顶叶区域，以观察TMS是否可以有效地阻止转移过程。该结果将弥合动物生理学和人类心理物理学之间的差距，为坐标转换提供见解。

DESCRIPTION (provided by applicant): Eye movements continuously produce shifts in the visual image on the retina. Despite these dynamic inputs, we perceive stability or constancy of the visual world. Constancy is presumably based on an internal representation of space derived from both retinal and non-retinal signals. This proposal aims to understand how the brain transforms across and separately utilizes different coordinate systems (representations), what extra-retinal signals are used for the modulation or coordinate-transformation processes, and what regions of the brain are responsible for such processes. We will apply a gaze manipulation paradigm to sensory-motor aftereffects such as saccade and arm-reach adaptation, attention-modulated perceptual effects and reaction times, as well as spatial localization and memory. We extend our paradigm to head and body turns utilizing a vestibular chair, and also employ Transcranial Magnetic Stimulation (TMS) to obtain insights into the underlying neural mechanism. A typical experiment with the gaze manipulation paradigm will consist of an adapting (cueing or target presentation) phase, followed by a testing phase to measure negative aftereffect, attentional modulation, or mislocalization. Unlike the conventional procedure, however, there will be a refixation phase between the adapting/cueing and the testing in which the observer has to move gaze to a new location. This enables us to isolate the adapted/cued location in eye-centered and the non-eye-centered, i.e. the head-, the body-, and the environment-centered coordinate frames of reference. By presenting the test stimulus at various locations, we will obtain a spatial tuning curve 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 either gaze-dependent modulation or a 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 and what extra-retinal signals are critical by rotating the observer's head and/or torso in a vestibular chair. We will further apply TMS to the parietal region of the observer who is performing an attentional cueing task with a gaze shift, to see if TMS can effectively block the transformation process. The results will bridge the gap between animal physiology and human psychophysics, providing insights into coordinate transformation.