The functional connectivity of the human visual system during development

我的研究计划的目标是了解人类视觉系统在发育过程中的功能组织和架构，并确定导致其长期和异质发展的机制。长期以来，视觉发育的研究一直被两个假说所指导：视觉发育在婴儿期完成，不同的视觉功能以相同的速度成熟。这就解释了为什么对婴儿期以后的视觉发展的研究仍然很少。我们实验室最近的一系列研究对这两个假设提出了严重的质疑。我们发现，一些视觉功能在儿童后期或青春期早期并不成熟，而且并不是所有的视觉功能都以同样的速度成熟。为了更好地理解这种旷日持久的成熟的机制，我们建议首次调查发育中的视觉系统功能连接和功能网络的变化。功能连接是指通过局部和远端皮质回路将空间上分离的大脑区域连接起来，以促进功能整合的连接和网络结构。大多数视觉功能的成熟依赖于特定视觉区域内部和区域之间的功能连接的发展，然而这一点还有待研究。我们将记录特定标记任务的视觉诱发电位，这些标记任务在视觉通路的不同区域诱导神经元激活。这将使我们能够研究1)区域间连通性、2)区域内连通性和3)功能网络结构的发展。这项研究对我们理解人脑发育很重要，因为它将提供关于视觉系统组织的关键见解，并使我们能够提出人类视觉系统中功能连接的工作模型。研究方案的几个方面是创新的。我们将提供第一个系统的和受控的研究视觉功能的连通性在发育过程中，从早期儿童到成年。这将使我们能够识别功能连接的神经生理学特征，并了解导致视觉感知不同方面的视觉结构之间的基本相互作用。我们的结果将为不同的视觉处理层如何整合和过滤信息，以及负责视觉感知发展的机制提供洞察力。这将引起神经科学、计算机科学、人工智能、生物学、工程学和医学等领域的研究人员的极大兴趣。这也有助于图像处理技术发展的工业进步。最后，我们的研究将使加拿大研究人员成为发展神经科学领域的国际领导者。

The objective of my research program is to understand the functional organization and architecture of the human visual system during development and identify the mechanisms responsible for its prolonged and heterogeneous development. Research on visual development has long been guided by two hypotheses: visual development is complete during infancy and different visual functions mature at the same rate. This explains why there are still few studies of visual development beyond infancy. A series of recent studies from our laboratory cast serious doubt about these two hypotheses. We found that several visual functions do not attain maturity before late childhood or early adolescence and that not all visual functions mature at the same rate. To better understand the mechanisms of this protracted maturation, we propose to investigate for the first time the changes in the functional connectivity and functional networks of the developing visual system. Functional connectivity represents the connections and network structure that link spatially separated brain regions through local and distal cortical circuits to facilitate functional integration. The maturation of most visual functions depends on the development of functional connectivity within and between specialized visual areas, however this has yet to be studied. We will record visual evoked potentials to specific marker tasks that elicit neuronal activation in different regions of the visual pathway. This will permit us to study the development of 1) inter-regional connectivity, 2) intra-regional connectivity, and 3) functional network structures. This research is important for our understanding of human brain development because it will provide key insight about the organisation of the visual system and permit us to propose a working model of functional connectivity in the human visual system. Several aspects of the research programme are innovative. We will provide the first systematic and controlled investigation of functional connectivity of visual function during of development, from early childhood to adulthood. This will allow us to identify the neurophysiological characteristics of functional connectivity and understand the fundamental interactions among the visual structures that give rise to different aspects of visual perception. Our results will provide insight about how the different tiers of visual processing integrate and filter information, as well as the mechanisms responsible for the development of visual perception. This will be of great interest for researchers in the fields of neuroscience, computer science, artificial intelligence, biology, engineering and medicine. This could also contribute to industrial advances in the development of image processing technologies. Lastly, our research will enable Canadian researchers to be international leaders in the field of developmental neurosciences.