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作为认知神经科学家的学术生涯，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作为主要的调查工具。培训的目的是获得这些方法的专门知识，特别是将它们结合起来。该领域的专家将指导候选人如何使用这些方法以及与视觉感知和选择性注意力有关的问题。将提供用于采集和分析EEC、MEG和fMRI数据的设施。本研究的目标是发展一种新的视网膜光密度约束的源估计方法，并使用这种新方法来估计多个视觉区域激活的时间过程。用fMRI测量的视网膜定位图和从高分辨率MRI图像构建的表面镶嵌将用于创建用MEG和EEG测量的视觉诱发反应的皮质发生器的逼真的、高度详细的模型。源估计将受到MEG和EEG对多个等偏心率视野位置处的刺激的响应的约束。随着刺激位置的变化，在给定的视觉区域中的等效电流偶极子以fMRI视网膜病变数据预测的方式在皮层表面移动。作为该方法的验证，刺激对比度和空间频率将变化。源估计的调制将与对相同刺激的事件相关fMRI响应的调制进行比较。最后，这种方法将被用来测量调制的时间分布在个别皮层区域的选择性空间注意。此外，早期视觉区域的活动将与注意力控制网络中的活动进行比较，注意力控制网络包括后顶叶皮层、额叶眼区和背外侧前额叶皮层。预计开发的方法将是相当大的使用在未来的研究中的视觉感知和注意力控制在正常的科目，并可能提供一个有价值的，非侵入性的方法的诊断和翻译研究的注意力控制障碍，如注意力缺陷障碍，自闭症谱系障碍，精神分裂症。该职业发展奖将提供多模态脑成像方法的必要培训，以及开发和测试想法的机会，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.