NEURAL ORGANIZATION OF COGNITION

现代认知神经科学的核心原则之一是，认知的神经结构被组织成解剖学上分离的子系统（模块），执行不同的功能。假设潜在的神经分离是由基因决定的，这通常是合理的，但在某些情况下，这种假设不容易适应。此外，神经科学领域越来越多的证据表明，经验能够而且确实导致所谓的大脑组织的定量变化（例如，现有功能区域大小的变化）。因此，人们很自然地会问：经验是否会导致大脑模块组织的质变（比如以前没有定位的功能的神经分离），还是神经模块总是由基因固定的？先前的患者研究表明，经验依赖功能（如阅读和写作）的选择性损伤表明，经验可能确实能够产生神经分离，尽管对这些发现的解释可能存在争议。我们建议通过使用一种独立的方法（神经影像学）来补充病变研究，以发展与该问题相关的证据。在这个问题上取得进展可能对我们对神经组织的理解、对神经系统患者的解释以及最终对脑损伤患者的康复具有重要意义。我们建议使用的方法是功能磁共振成像（fMRI）。fMRI有许多特点，使其成为解决经验依赖的神经分离问题的理想选择：(1)它的空间分辨率（1-5mm3）足够精确，可以检测功能模块的解剖分离；(2)通常可以在个体中获得显著的结果，无需在受试者之间进行平均（这是一个临界点，因为所研究的潜在神经组织可能在个体之间有所不同）；(3)它可以用于神经系统完整的人类受试者。我们的计划是通过调查三个子问题来发展关于经验依赖的神经分离的聚合证据：(1)字母识别与数字识别是否分离？(2)关于数字的语义知识是否与关于其他类别的语义知识分离？(3)不同的语言在双语中是否被隔离？我们选择这些域名有四个原因。首先，在每种情况下，假定的分离功能都可能因脑损伤而选择性受损（这表明它可能是分离的）。其次，在每一种情况下，假设任何潜在的神经分离都是与生俱来的，都是有问题的。第三，功能可以相对较好地与控制任务相匹配（使得将积极结果归因于工件变得更加困难）。第四，这些功能可以很容易地使用功能磁共振成像（fMRI）来研究（例如，它们不需要大量的运动）。通过并行研究这三个领域，我们希望发展出收敛的证据，这将使我们能够得出与经验依赖的神经分离问题相关的更一般的结论。

One of the central tenets of modern cognitive neuroscience is that the neural architecture of cognition is organized into anatomically segregated subsystems (modules) that perform different functions. It is usually plausible to assume that the underlying neural segregation was genetically predetermined, but there are cases that this hypothesis cannot easily accommodate. Furthermore, a growing body of evidence in neuroscience has demonstrated that experience can and does lead to what might be called quantitative changes in brain organization (e.g., changes in the size of an existing functional region). It is therefore natural to ask: Can experience lead to qualitative changes in the brain's modular organization (such as the neural segregation of a function that was not previously localized) or are neural modules always hard-wired by genetics? Previous patient work demonstrating selective impairments in experience-dependent functions (e.g., reading and writing) suggests that experience may indeed be able to produce neural segregation, although the interpretation of those findings can be controversial. We propose to develop converging evidence relevant to the issue by using an independent methodology (neuroimaging) that complements lesion studies. Making progress on this issue could have important implications for our understanding of neural organization, for the interpretation of neurological patients, and ultimately for the rehabilitation of patients with brain damage. The method we propose to use is functional magnetic resonance imaging (fMRI). fMRI has a number of features that make it ideal for addressing the issue of experience-dependent neural segregation: (1) its spatial resolution (1-5mm3) is sufficiently fine to detect anatomic segregation of functional modules, (2) significant results can typically be obtained in individuals making it unnecessary to average across subjects (a critical point because the underlying neural organization under study may differ across individuals), and (3) it can be used with human subjects who are neurologically intact. Our plan is to develop converging evidence regarding experience- dependent neural segregation by investigating three sub- questions: (1) Is letter recognition segregated from digit recognition? (2) Is semantic knowledge about numbers segregated from semantic knowledge about other categories? (3) Are different languages segregated in bilinguals? We chose these domains for four reasons. First, in each case the putatively segregated function can be selectively impaired by brain damage (suggesting that it may be segregated). Second, in each case it is problematic to assume that any underlying neural segregation could be hard-wired. Third, the functions can be relatively well matched with control tasks (making it more difficult to attribute positive results to artifacts). And fourth, the functions can be readily studied using fMRI (e.g., they do not require extensive movement). By studying these three domains in parallel we hope to develop converging evidence that will allow us to draw more general conclusions relevant to the issue of experience-dependent neural segregation.