权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Neural correlates of spatiotemporal form intergation

时空形式整合的神经关联

基本信息

批准号：
9461642
负责人：
Gennady Erlikhman
金额：
$ 0.16万
依托单位：
UNIVERSITY OF NEVADA RENO
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-08-03 至 2018-08-02
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9461642
关键词：
Address Affect Area Autistic Disorder Brain Categories Cells Communication Complex Data Disease Dorsal Electroencephalography Environment Feedback Form Perception Functional Magnetic Resonance Imaging Functional disorder Goals Human Income Lateral Length Maintenance Modeling Motion Neurons Occipital lobe Paper Parietal Lobe Pathway interactions Perception Play Population Population Research Positioning Attribute Process Published Comment Research Retina Role Schizophrenia Shapes Signal Pathway Signal Transduction Source Stimulus Stream Techniques Testing Time Visual Visual Cortex Visual Fields Visual system structure area V1 design experimental study extrastriate visual cortex fusiform face area interest intraparietal sulcus neural correlate object perception prevent public health relevance receptive field relating to nervous system source localization spatiotemporal visual information visual motor visual processing

项目摘要

DESCRIPTION (provided by applicant): The neural correlates of object perception have been traditionally identified in ventral cortical regions that form a visual processing hierarchy, with deeper regions containing cells with larger receptive fields that are thought to underlie abstract (viewpoint-, position-, and scale-invariant) object representations. These forms of representational invariance are important for the categorization and identification of static objects. However, most objects in our natural environment are not fully visible due to occlusion and are not static as they or as we move. Rather than representational invariance, the visual system requires precise representations about object fragment position, velocity, and orientation in order to integrate many fragments across space and time into perceptual wholes or spatiotemporal objects. We have conducted two preliminary studies that suggest that dorsal regions (V3A, V3B, and the intraparietal sulcus) may be involved in the representation of dynamic forms. This opens the question of whether shape information in dorsal and ventral areas is similar or redundant or whether there is communication and a relaying of information between them that ultimately leads to both invariant representations in ventral areas and specific representations in dorsal areas. To identify the signaling pathway (Aim 1), subjects will perform a shape identification task with objects that are gradually revealed over time (spatiotemporal objects) or with objects whose shape information is available all at once while EEG data is recorded. In order to relate the signaling time-course to cortical areas, structural and functional MRI data will be collected in order to enhance source-localization accuracy and to define ROIs in source-localized space. Using MVPA, we will decode shape identity in each ROI as a function of time. If spatiotemporal object representations are first constructed in dorsal areas and then passed down to ventral ones, shape decoding will be possible earlier after stimulus onset in dorsal areas than in ventral. Static object identity may only be decodable in ventral regions. To confirm the causal role of dorsal areas in spatiotemporal object representation (Aim 2), we will conduct two experiments in which we apply transcranial direct current stimulation (tDCS) to posterior parietal cortex (dorsal visual areas) to disrupt dynamic form integration. If dorsal areas are necessary for integration of shape information over time, tDCS should decrease the time over which such forms can be integrated, but should have no effect on the perception of static shapes.

描述（由申请人提供）：传统上，在形成视觉处理层次的腹侧皮层区域中识别出物体感知的神经相关性，其中较深的区域包含具有较大感受野的细胞，这些感受野被认为是抽象（视点、位置和尺度不变）物体表征的基础。这些形式的表征不变性对于静态对象的分类和识别非常重要。然而，我们自然环境中的大多数物体由于遮挡而不能完全可见，并且在它们或我们移动时不是静态的。视觉系统需要的不是表征不变性，而是关于物体碎片位置、速度和方向的精确表征，以便将跨越空间和时间的许多碎片整合成感知整体或时空物体。我们已经进行了两个初步的研究表明，背侧区域（V3A，V3B，和顶内沟）可能参与动态形式的表征。这就提出了一个问题，即背侧和腹侧区域的形状信息是否相似或冗余，或者它们之间是否存在通信和信息中继，最终导致腹侧区域的不变表示和背侧区域的特定表示。为了识别信号通路（目标1），受试者将使用随时间逐渐显示的对象（时空对象）或使用其形状信息在记录EEG数据时立即可用的对象执行形状识别任务。为了将信号时间过程与皮质区域相关联，将收集结构和功能MRI数据，以提高源定位准确性并定义源定位空间中的ROI。使用MVPA，我们将解码每个ROI中的形状标识作为时间的函数。如果时空对象表征首先在背因此，背侧区的形状解码比腹侧区更早。静态对象身份可能仅在腹侧区域中可解码。为了证实背侧区域在时空对象表征（目标2）中的因果作用，我们将进行两个实验，其中我们将经颅直流电刺激（tDCS）应用于后顶叶皮层（背侧视觉区），以破坏动态形式整合。如果背侧区域对于形状信息的整合是必要的，那么tDCS应该减少这种形式可以整合的时间，但对静态形状的感知没有影响。