Spatiotemporal Mapping of Visual Evoked cortical Activity and Spatial Attention

描述（由申请人提供）：候选人的长期目标是追求学术生涯，成为一名认知神经科学家，专注于认知过程的执行控制，如注意力，工作记忆和决策，使用EEC， MEG和fMRI作为主要研究工具。培训的目的是获得这些方法的专门知识，特别是这些方法的综合。候选人将由该领域的专家指导这些方法的使用以及与视觉感知和选择性注意相关的问题。获取和分析EEC， MEG和fMRI数据的设备将可用。本研究计划的目标是开发一种新的视网膜切除约束源估计方法，并利用该方法估计多个视觉区域的激活时间过程。用功能磁共振成像测量的视网膜定位图和由高分辨率MRI图像构建的表面镶嵌图将用于创建用MEG和EEG测量的视觉诱发反应的皮层发生器的逼真的、高度详细的模型。源估计将受到在多个等偏心视野位置对刺激的MEG和EEG反应的约束。随着刺激位置的改变，给定视觉区域的等效电流偶极子以fMRI视网膜切除数据预测的方式穿过皮质表面。作为该方法的验证，刺激对比度和空间频率将发生变化。源估计的调制将与对相同刺激的事件相关fMRI反应的调制进行比较。最后，该方法将用于测量通过选择性空间注意在单个皮质区域调制的时间剖面。此外，早期视觉区域的活动将与由后顶叶皮层、额叶视野和背外侧前额叶皮层组成的注意控制网络的活动进行比较。预计该方法将在未来对正常人的视觉感知和注意力控制的研究中有相当大的应用，并可能为注意力控制障碍（如注意缺陷障碍、自闭症谱系障碍和精神分裂症）的诊断和转化研究提供有价值的、非侵入性的方法。这个职业发展奖项将提供必要的多模态脑成像方法培训，以及发展和测试想法的机会，为未来的研究创造策略和基础。

DESCRIPTION (provided by applicant): The candidate's long-term goal is to pursue an academic career as a cognitive neuroscientist with a focus on executive control of cognitive processes such as attention, working memory, and decision making, using EEC, MEG, and fMRI as the primary investigative tools. The purpose of the training is to gain expertise in these methods and in particular their integration. The candidate will be instructed by experts in the field on the use of these methods and on issues related to visual perception and selective attention. Facilities for the acquisition and analysis of EEC , MEG, and fMRI data will be available. The goal of the research plan is to develop a new retinotopy-constrained source estimation method and use this new method to estimate the time courses of activation in multiple visual areas. Retinotopic maps measured with fMRI and surface tesselations constructed from high resolution MRI images will be used to create realistic, highly detailed models of the cortical generators of visual evoked responses measured with MEG and EEG. Source estimates will be constrained by MEG and EEG responses to stimuli at multiple iso-eccentricity visual field locations. As the stimulus location changes, the equivalent current dipole in a given visual area moves across the cortical surface in a way predicted by fMRI retinotopy data. As a validation of this method, stimulus contrast and spatial frequency will be varied. The modulation of source estimates will be compared to the modulation of event-related fMRI responses to the same stimuli. Finally, this method will be used to measure the temporal profile of modulation in individual cortical areas by selective spatial attention. Furthermore, activity in early visual areas will be compared to activity in the attentional control network comprising posterior parietal cortex, frontal eye fields, and dorsolateral prefrontal cortex. It is anticipated that methods developed will be of considerable use in the future study of visual perception and attentional control in normal subjects and may provide a valuable, non-invasive method for the diagnosis and translational study of disorders of attentional control such as attention-deficit disorder, autism spectrum disorders, and schizophrenia. This career development award will provide necessary training in multi-modal brain imaging methods as well as an opportunity to develop and test ideas, creating strategies and foundations for future study.