Functional circuits of the visual cortex

在大脑中处理视觉信息的区域，细胞通过改变它们的电活动模式来对视觉刺激的呈现做出反应。在分析的第一级，初级视觉皮层（V1），单个细胞只有当特定方向的线段或边界出现在它们的检测范围内时才会活跃，这包括视觉场景的一小部分。与V1区相比，其他视觉皮质区（层外皮层）的细胞执行更复杂的检测任务，V1区需要整合来自视觉场景更大部分的信息。这些更复杂的特性的一个例子是远程轮廓整合现象，在这种现象中，我们的视觉系统将具有相似方向的单个线段分组，以便将它们视为同一轮廓的一部分。这种特性反映在背内侧视觉区（DM）细胞的电反应上。定向特异性和远程轮廓整合等特性是如何产生的？为了开始解决这个问题，我们将研究已识别细胞的生理特性、它们的信息收集区域（树突）的空间分布以及它们从大脑其他部分接收信息的解剖途径之间的相关性。这是一项基础科学研究，旨在确定大脑的解剖结构在多大程度上有助于确定单个细胞和大脑区域的功能。它的主要好处将是增加我们对大脑中所有感觉处理的机制的理解。所获得的知识也可能导致应用研究领域的发展，包括医学和认知科学（例如，了解大脑如何在生命早期学习解释视觉信息，以及视觉处理如何随着年龄的增长而退化）。

In the areas of the brain where visual information is processed, cells respond to the presentation of visual stimuli by changing their pattern of electrical activity. At the first level of analysis, the primary visual cortex (V1), individual cells become active only if line segments or borders of a particular orientation are present in their field of detection, which encompasses a small part of the visual scene. Cells in other visual cortical areas (the extrastriate cortex) perform more complex detection tasks in comparison with those in V1, which demand integration of information coming from much larger portions of the visual scene. One example of these more complex properties is the phenomenon of long-range contour integration, where our visual system groups individual line segments having similar orientations, so that they are perceived as part of the same contour. This property is reflected in the electrical responses of cells in the dorsomedial visual area (DM). How are properties such as orientation specificity and long-range contour integration created? To begin addressing this question, we will investigate correlations between the physiological properties of identified cells, the spatial distribution of their information collecting regions (dendrites), and the anatomical pathways by which they receive information from other parts of the brain. This is a basic science study aimed at determining the extent to which the anatomical structure of the brain helps define the function of individual cells and brain areas. Its primary benefit will be to increase our understanding of the mechanisms underlying all sensory processing in the brain. The knowledge obtained may also lead to developments in areas of applied research including medicine and cognitive science (for example, understanding how the brain learns to interpret visual information in early life, and how visual processing degrades with ageing).