DEVELOPMENT OF COGNITIVE FUNCTIONS: FRONTAL LOBE

这项拟议研究的目标有三：(1)对儿童进行测试 在测试(A)中，大脑损伤局限于额叶皮质， 与额叶皮质功能通过神经解剖学和 对幼猴和成年猴子的行为研究以及(B)我们所知道的 儿童的正常发育进程。这方面的重要方面 工作将是从所有相关的不同测试中寻找趋同的证据 前额叶皮质的同一分区，并试图解离 这些测试的性能来自与其他神经网络连接的测试的性能 电路。目标是开发非侵入性测试，能够检测 婴幼儿的额叶皮质损害。目前这样的损害 由于缺乏这样的检测，很多年都没有被发现。 (2)研究多巴胺水平与运动成绩的关系 这些任务，并开始调查假设 认知的出现基础上的根本性成熟变化 在婴儿期依赖额叶皮质的能力水平正在提高 额叶皮质中的多巴胺。为了做到这一点，接受早期治疗的北大儿童， 他们没有已知的结构性脑损伤，但容易受到 将测试多巴胺的水平。因为他们的一般认知 运转良好，如果发现赤字，它们很可能是有选择性的。 如果他们在额叶皮质功能测试中受到选择性损害，这 这将是人类第一次证明额叶存在认知缺陷 仅多巴胺耗尽所致的大脑皮层任务。因为L-多巴和多巴胺 前体酪氨酸，可以口服，有很好的机会 如果发现缺陷，治疗性干预将有可能 减轻任何损伤。 (3)更好地了解成功完成以下任务所需的能力 依赖于额叶皮质功能。假设将被考虑 建议记忆用于空间和/或时间，或用于关系信息 一般说来是可以从记忆中分离出来的，用于其他信息和依赖 影响额叶皮质功能。

The goals of the proposed research are three:(1) to test children with brain damage localized to frontal cortex on tests (a) which have been linked specifically to frontal cortex function through neuroanatomical and behavioral studies with infant and adult monkeys and (b) on which we know the normal developmental progression in children. Important aspects of this work will be to look for converging evidence from diverse tests all linked to the same subregion of frontal cortex, and to attempt to dissociate performance on these tests from performance on tests linked to other neural circuits. The goal is to develop non-invasive tests capable of detecting frontal cortex damage in infants and young children. Presently such damage often goes undetected for many years because of the lack of such tests. (2) to investigate the relationship of dopamine levels to performance on these tasks, and to begin to investigate the hypothesis that the fundamental maturational change which underlies the emergence of cognitive abilities dependent on frontal cortex during infancy is increasing levels of frontal cortex dopamine. To do this, children with early-treated PKU, who have no known structural brain damage but who are vulnerable to reduced levels of dopamine will be tested. Because their general cognitive functioning is good, if deficits are found they are likely to be selective. If they are selectively impaired on tests of frontal cortex function, this will be the first demonstration in humans of a cognitive deficit on frontal cortex tasks from dopamine depletion alone. Because L-dopa and the dopamine precursor, tyrosine, can be taken orally, there is an excellent chance that if deficits are found, therapeutic interventions will be possible to alleviate any impairments. (3) to better understand the abilities required for success on tasks that depend on frontal cortex function. Hypotheses will be considered that suggest that memory for space, and/or time, or for relational information in general is dissociable from memory for other information and dependent upon frontal cortex function.