Multisensory Form Processing in Extrastriate Visual Cortex

人类的功能性神经成像研究已经证实，许多视觉皮质区域在触觉任务中被招募。需要更多的方法来描述这种视觉皮层活动在非视觉感知过程中的作用和潜在的神经机制。在国家科学基金会的资助下，这项研究体现了两位博士之间的合作。Krishnankutty Sathian， John Foxe和Charles Schroeder带来了不同的技术来处理外层视觉皮层的多感觉形式处理问题。人类的功能磁共振成像（fMRI）正在与人类的事件相关电位（ERP）研究和猕猴的神经生理学研究相结合，使用三种方法共同的实验设计。功能磁共振成像的高空间分辨率和ERP研究的高时间分辨率是相辅相成的，可以说明神经活动的时间特征，以及精确的定位。猴子研究需要结合场电位和动作电位分析，可以直接与人类（ERP/fMRI）数据进行比较，并研究ERP和fMRI效应的细胞基础。特异性目的1研究触觉形式辨别对视觉皮层活动的招募，特异性目的2研究触觉形式感知过程中视觉和触觉之间的多感官相互作用。将三种互补的实验方法结合起来，使用一组共同的任务来处理一组共同的问题，这是独一无二的，并且有望提供比任何单独的方法更完整的相关神经过程的图像。这种三方面的方法可以获得关于多感觉相互作用的特定大脑机制的趋同证据，这些机制越来越被认为是无处不在的，对感觉处理以及认知的其他方面至关重要。在其更广泛的影响中，该项目体现了在一系列问题上采用多种实验方法的价值。预计该项目最终将导致改善辅助技术，以提供给任何类型的感官剥夺的个人。通过在三位主要研究人员之间建立长期合作，学生和博士后学员将能够获得多种实验方法的专业知识，与多个导师互动，进一步在新兴的多感官科学领域进行明确的培训，这是一个很少有正式培训机会的领域。

Functional neuroimaging studies in humans have established that many visual cortical areas are recruited during tactile tasks. Additional methodological approaches are necessary to characterize the role of such visual cortical activity during non-visual perception and the underlying neural mechanisms. With National Science Foundation funding, this research embodies a collaboration among Drs. Krishnankutty Sathian, John Foxe, and Charles Schroeder that brings different techniques to bear on the issue of multisensory form processing in extrastriate visual cortex. Functional magnetic resonance imaging (fMRI) in humans is being combined with event-related potential (ERP) studies in humans and neurophysiologic studies in macaque monkeys, using experimental designs common to the three methods. The high spatial resolution of fMRI and the high temporal resolution of ERP studies are mutually complementary and allow specification of the temporal profile of neural activity, as well as precise localization. Monkey studies entail a combination of field potential and action potential analyses that allow both direct comparison to human (ERP/fMRI) data and investigation of the cellular bases of ERP and fMRI effects. Specific Aim I investigates the recruitment of visual cortical activity by tactile form discriminations and Specific Aim II explores multisensory interactions between vision and touch, during tactile form perception. The combination of three complementary experimental approaches being brought to bear on a common set of questions, using a common set of tasks, is unique and promises to provide a much more complete picture of the relevant neural processes than any of the approaches in isolation. This tripartite approach allows the acquisition of convergent evidence on the specific brain mechanisms of multisensory interactions, which are increasingly recognized to be ubiquitous and essential for sensory processing as well as other aspects of cognition. Among its broader impacts, this project exemplifies the value of bringing multiple experimental approaches to bear on a set of issues. The project is anticipated to lead eventually to improvement in assistive technology available to individuals with sensory deprivation of any kind. By establishing a long-term collaboration between the three principal investigators, students and post-doctoral trainees will be able to acquire expertise in more than one of the experimental approaches, interact with more than one mentor, and further, train explicitly in the emerging field of multisensory science, a field with few formal training opportunities.