Neural correlates of active vision

对大脑过程的主要洞察来自于研究过程是如何受到自上而下的影响的。具体地说，人们对行为如何塑造感知的兴趣与日俱增。脑成像加深了对参与视觉运动转换的神经网络的理解。然而，人们对这些转换的时间方面知之甚少，因为大脑成像无法及时解析小细节，而且脑电(EEG)是以空间分辨率较低为代价的。因此，知觉区域的依赖动作的激活是如何随时间演变的，目前还知之甚少。 然而，多变量分析的最新进展表明，从人类头皮记录的脑电数据允许详细了解视觉和视觉运动计算的时间进程。 我的研究项目的目标是 -显示大脑对动作的准备触发感知区域的活动，该区域携带有关动作对象的信息，并识别这些依赖动作的激活的目的 -确定大脑活动在空间和时间上的模式，这些模式将有关行动目标对象的多个方面的信息结合在一起 -确定依赖于动作的感知信息工作的空间坐标系 我将使用多变量脑电分析，单独使用或与脑成像结合使用。 我这个项目的主题1旨在表明，脑电信号反映的是关于物体形状的视觉信息，这些视觉信息在时间上与随后的抓取保持一致，而不是到达不需要形状信息的运动。我将测试有关脑电信号中嵌入了哪些对象部分的信息(可能是参与者将抓住的点附近的部分)。我将测试感觉与看起来不同的物体的脑电反应，以探索动作控制机制。此外，我还将探讨掌握记忆和工作记忆之间的干扰。 主题2将研究与物体有关的多个视觉方面的动作依赖增强的神经关联，这些视觉方面传达关于物体的形状、大小和重量的信息，这些特征对计划抓取很重要。我将使用EEG和大脑成像来整合关于大脑活动的详细的时间和空间信息。 主题3将关注手部位置、眼球运动以及物体方向对视觉形状信息的动作激活的影响。 总而言之，这项拟议的研究将寻求一种全面的方法来调查一些与行动相关的主要自上而下对视觉的影响，有效地利用这些机制作为镜头来研究行动中的视觉系统。这项研究的结果有可能进一步加深我们对大脑作为一个动态系统的理解，这个系统根据大脑的目标和行动塑造其感知过程，对未来脑机接口的发展具有额外的重要影响。

Major insights into the brain's processes come from studying how processes are modulated by top-down effects. Specifically, there is growing interest in how actions shape perception. Brain imaging has deepened the understanding of the neural networks engaged in visuomotor transformations. Yet there is little knowledge of the temporal aspects of these transformations, because brain imaging cannot resolve small details in time, and because electroencephalography (EEG) comes at the expense of poor spatial resolution. Thus, there is little understanding of how action-dependent activation of perception regions evolves in time. Recent advances in multivariate analysis, however, have demonstrated that EEG data recorded from the human scalp allow for detailed insights into the time course of visual and visuomotor computations. The objectives of my research project are - show that the brain's preparations for actions trigger activity in perceptual areas that carry information about the objects of actions, and to identify the purpose of these action-dependent activations - identify the patterns of brain activity in space and time that bind together information about multiple aspects of objects targeted by actions - identify the spatial coordinate systems in which action-dependent perceptual information works I will use multivariate EEG analysis, alone or in combination with brain imaging. Theme 1 of my project aims to show that EEG signals reflect visual information about object shapes that builds up aligned in time with subsequent grasp but not reach movements which require no shape information. I will test information about which object parts are embedded in the EEG signals (probably parts near the points where participants will grasp). I will test EEG responses to objects that feel different from what they look like to probe for action control mechanisms. Also, I will probe for interference between grasping and working memory. Theme 2 will investigate the neural correlates of action-dependent enhancement of multiple visual aspects about objects conveying information about shape, size, and weight of objects features important to plan grasping. I will use EEG together with brain imaging to integrate detailed temporal and spatial information about brain activity. Theme 3 will be concerned with the influences of hand positions, eye movements as well as object orientations on action-dependent activation of visual shape information. In sum, the proposed research will pursue a comprehensive approach to investigating some of the major action-related top--down influences on vision, effectively using these mechanisms as a lens to study the visual system in action. The outcome of this research has the potential to further our understanding of the brain as a dynamic system that shapes its perceptual processes, depending on its goals and actions with additional important implications for the development of future brain-computer interfaces.