Ventral and dorsal visual streams in action planning

描述(由申请人提供)：Scott H.Johnson博士是一名认知心理学家，并建立了一项关于物体感知和理解的积极研究计划。这一奖项的目的是让Scott发展更多必要的知识、技能和经验，以追求这些过程的行为和神经基础。这一目标将在赞助商Scott G.Grafton和 联合赞助商南希·G·坎维舍、安德鲁·巴托。功能磁共振成像和心理物理学研究将在达特茅斯学院认知神经科学中心进行，斯科特目前是该中心的研究助理教授。其他培训将通过巴托？S博士进行。 马萨诸塞大学的计算机运动实验室和麻省理工学院的坎维舍？S博士的实验室。 拟议的研究计划描述了一系列旨在增加我们对人类腹侧和背侧视觉流对视觉引导动作规划的贡献的研究，即工具抓取和操纵。这些实验采用了各种策略(事件相关功能磁共振成像、心理物理学和计算建模)来评估假设，这些假设既有计算方面的考虑，也有目前已知的视觉和运动系统的功能结构。众所周知，灵长类动物纹外视区被组织成两个主要的加工流：枕颞流(即腹侧)和枕顶流(即背侧)。这些流中的区域之间存在相互联系，这两条路径都为参与工作记忆和规划的前额叶皮质区域提供视觉输入。目前，这一组织对人类行为的功能意义还没有得到很好的理解，仍然是一个活跃的争论来源。来自电生理学和神经成像的最新证据指出了当前理论的不足，并表明这两个流中的区域可能比之前假设的更具互动性。基于初步结果，本研究将评估另一种模型，在该模型中，据说人类背侧和腹侧流中的区域通过相互的相互连接和/或通过来自前额叶结构的反馈在 行动计划。

DESCRIPTION (provided by applicant): Scott H. Johnson, Ph.D. was trained as a cognitive psychologist and has established an active research program in object perception and prehension. The purpose of this award is to allow Scott to develop additional knowledge, skills and experience necessary to pursue both the behavioral and neural bases of these processes. This goal will be undertaken with the support and supervision of sponsor Scott G. Grafton and co-sponsors Nancy G. Kanwisher, Andrew Barto. Functional MRI, and psychophysical studies will take place at the the Center for Cognitive Neuroscience at Dartmouth College where Scott is currently a Research Assistant Professor. Additional training will be pursued through Dr. Barto?s computational motor lab at the University of Massachusetts and Dr. Kanwisher?s lab at M.I.T. The proposed research plan describes a series of studies designed to increase our understanding the contributions of the human ventral and dorsal visual streams to the planning of visually-guided actions; i.e., tool prehension and manipulation. These experiments employ a variety of strategies (event-related fMRI, psychophysics, and computational modeling) to evaluate hypotheses motivated both by computational considerations and what is currently known about the functional architecture of the visual and motor systems. It is well-established that extrastriate visual areas of primates are organized into two primary streams of processing: an occipital-temporal (i.e., ventral) stream, and an occipital-parietal (i.e., dorsal) stream. Reciprocal connections exist between areas within these streams, and both pathways provide visual input to regions of prefrontal cortex that are involved in working memory and planning. At present, the functional significance of this organization for human behavior is not well-understood, and remains a source of active debate. Recent evidence from electrophysiology and neuroimaging point to the inadequacies of current theories, and suggest that areas within both streams may be considerably more interactive than previously supposed. Based on preliminary results, the present studies will evaluate an alternative model in which areas within the human dorsal and ventral streams are said to interact directly--via reciprocal interconnections, and/or indirectly-- through feedback from the prefrontal structures, during action planning.