Coordinate Transformation in Aftereffects and Attention

描述（由申请人提供）：眼球运动连续地在视网膜上的视觉图像中产生移位。尽管有这些动态的输入，我们还是感知到视觉世界的稳定性或恒定性。恒常性大概是基于从视网膜和非视网膜信号两者导出的空间的内部表示。该提案旨在了解大脑如何转换并分别利用不同的坐标系（表示），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。我们将应用凝视操作范式的感觉运动后效应，如扫视和手臂达到适应，注意力调节的感知效果和反应时间，以及空间定位和记忆。我们扩展我们的范例，头部和身体轮流利用前庭椅，并采用经颅磁刺激（TMS），以获得深入了解潜在的神经机制。一个典型的实验与凝视操作范式将包括一个适应（提示或目标呈现）阶段，然后是一个测试阶段，以衡量负面的后效，注意力调节，或定位错误。然而，与传统程序不同的是，在适应/提示和测试之间将存在重新注视阶段，其中观察者必须将视线移动到新的位置。这使得我们能够隔离以眼睛为中心的和非以眼睛为中心的（即，以头部、身体和环境为中心的参考坐标系）中的适应/提示位置。通过在不同的位置呈现测试刺激，我们将获得一个空间调谐曲线，以找出视觉系统保持以眼为中心的表示的程度，和/或将其转换为非以眼为中心的描述。如果我们发现凝视依赖性调制或非眼中心分量，如我们的试点研究所示，我们将通过在前庭椅中旋转观察者的头部和/或躯干来准确地确定哪个非眼中心系统（头部，身体或环境中心）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应用于正在执行具有注视转移的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换过程。这些结果将弥合动物生理学和人类心理物理学之间的差距，为坐标变换提供见解。

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.