NEURAL COMPUTATIONS IN VISUAL CORTEX

我们计划研究初级视皮层的视觉信息加工过程， 猕猴在局部场电位水平和 单个单元。在最初的资助期间，我们制定了一套 技术来检查和模拟空间和时间的相互作用， 视觉皮层的高级细节和复杂程度。结果 通过这些技术获得的证据表明， 在提取VI的空间特征时， 特征、分割和时间编码。计划中的研究将 建立在这些调查结果，并将组织沿着两条线： 一类横向相互作用的功能作用，以及 视觉输入对时间相关性的影响 神经活动的结构。 横向相互作用的研究将确定它们如何依赖于 对比度，它们是否携带空间尺度上的信息，彩色 内容，或方向，无论他们选择性地调节只有一些 皮质形态加工的各个方面，以及它们是否在各层中有所不同。 这些问题的答案将有助于确定这些相互作用是否 对于特征提取、分割、“填充”和 其他进程。 视觉刺激如何调节正在进行的相关结构的研究 的神经活动将开始开始与使用锁相频谱 分析测试这个过程的动态模型。然后我们将检查 这一过程的空间范围， 关于视觉刺激的特定信息，及其层 organization.这些发现将有助于确定在何种程度上VI 将视觉信息转换为时间代码，以及这种时间代码如何 生成代码。 这项研究的一个中心主题是，非线性是非常重要的， 在空间和时间处理中的功能重要性。一 成功地研究复杂的非线性系统需要剪裁的 用实验的方法来解决感兴趣的生物学问题。因此，我们认为， 这项研究计划的一个明确部分是继续发展 探索非线性神经网络的新实验和分析技术 系统，以及理论和实验之间的紧密互动。 视觉信息处理被认为是一个模型的感觉 一般的信息处理。分析横向和横向的作用 的相互作用和正在进行的神经活动的时间模式 形状和颜色的处理使我们能够研究特征提取，交叉， 通道的相互作用，和神经编码的背景下，具体 可以提出假设并可以测试模型。

We plan to study visual information processing in primary visual cortex of the macaque monkey at the level of the local field potential and the single unit. In the initial funding period, we have developed a set of techniques to examine and model spatial and temporal interactions in the visual cortex at an advanced level of detail and sophistication. Results obtained with these techniques have provided evidence of the involvement of VI in the extraction of spatial features, the linking of these features, segmentation, and temporal coding. The planned research will build on these findings, and will be organized along two lines: the functional role of a class of lateral interactions, and the functional role of the influence of visual inputs on the temporal correlation structure of neural activity. The study of lateral interactions will determine how they depend on contrast, whether they carry information on spatial scale, chromatic content, or orientation, whether they selectively modulate only some aspects of cortical form processing, and whether they vary across laminae. Answers to these questions will help determine whether these interactions are important for feature extraction, segmentation, "filling-in", and other processes. The study of how visual stimuli modulate the ongoing correlation structure of neural activity will begin with the use of phase-locked spectral analysis to test dynamical models for this process. We will then examine the spatial extent of this process, the degree to which it carries specific information concerning the visual stimulus, and its laminar organization. These findings will help determine to what extent VI transforms visual information into a temporal code, and how such temporal codes are generated. A central theme in this research is that nonlinearities are of great functional importance in both spatial and temporal processing. A successful study of complex nonlinear systems requires tailoring of the experimental approach to the biological questions of interest. Therefore, an explicit part of this research program is the continued development of new experimental and analytic techniques to probe nonlinear neural systems, and a tight interaction between theory and experiment. Visual information processing is considered to be a model for sensory information processing in general. Analysis of the roles played by lateral interactions and temporal patterns of ongoing neural activity in the processing of form and color allow us to study feature extraction, cross- modality interactions, and neural coding in a context in which specific hypotheses may be proposed and models may be tested.