Enhancing Human Cortical Plasticity: Visual Psychophysics and fMRI

在美国国家科学基金会（National Science Foundation）的支持下，波德拉克博士将对一种增强大脑可塑性和提高成年人学习速度的新方法进行为期一年的研究。人们早就知道，大脑在生命早期发生了广泛的变化，这些变化取决于儿童环境中的特定经历。然而，最近的研究发现，随着经历的变化，大脑在整个成年期都会继续发生变化。这种改变的能力被称为可塑性，被认为是许多学习形式的基础。波德拉克博士的项目将探索一种基于实验动物研究结果的方法，实验动物研究表明，通过增加神经递质乙酰胆碱的水平，大脑皮层的可塑性可以大大增强。被称为胆碱酯酶抑制剂的新药最近被开发出来并获得了fda的批准，这种药物可以安全有效地增加人体内的乙酰胆碱水平。波德拉克博士将使用的具体药物是氢溴酸加兰他明（商品名雷米尼）。药物对皮质可塑性的影响将通过视觉行为测试和功能性磁共振成像来评估，磁共振成像是一种非侵入性的方法，用于测量一个人在执行认知或感知任务时发生的大脑活动。行为测量将是受试者学会更准确地完成一项简单的视觉感知学习任务的速度：学会辨别光栅的方向。要测试的假设是，在药物影响下学习视觉任务的速度要比在安慰剂作用下学习的速度快。功能性磁共振成像将用于评估药物对皮质可塑性的影响，通过比较训练前与训练后大脑激活的变化，分别是由服用药物学习视觉任务和服用安慰剂学习视觉任务引起的。如果这种增强可塑性的新方法能够成功，它将提供关于成人大脑可塑性本质的重要而新颖的知识，并可能导致广泛的潜在临床和实际应用。了解成年人大脑的可塑性是如何工作的至关重要，因为最近的研究表明，可塑性可以用来治疗神经系统问题，如中风或重复性劳损导致的运动障碍，以及阅读和语言障碍。

With National Science Foundation support, Dr. Poldrack will conduct a year long investigation of a new approach to enhancing brain plasticity and increasing the speed of learning in adult humans. It has long been known that the brain changes extensively early in life, and that these changes are dependent upon particular experiences in the child's environment. However, more recent research has discovered that the brain continues to change throughout adulthood in response to experience. This ability to change is called plasticity, and is thought to underlie many forms of learning. Dr. Poldrack's project will explore an approach based upon results from studies of experimental animals, which have shown that plasticity in the cerebral cortex can be greatly enhanced by increasing the levels of the neurotransmitter acetylcholine. New drugs, known as cholinesterase inhibitors, that safely and effectively increase acetylcholine levels in humans have recently been developed and FDA-approved. The specific drug that Dr. Poldrack will use is galanthamine hydrobromide (tradename Reminyl). The effect of the drug on cortical plasticity will be assessed using both visual behavioral testing and functional magnetic resonance imaging, which is a non-invasive method for measuring the brain activity that occurs as a person performs a cognitive or perceptual task. The behavioral measure will be the rate at which the subjects learn to more accurately perform a simple visual perceptual learning task: learning to discriminate the orientation of a grating. The hypothesis to be tested is that learning of the visual task that takes place under the influence of the drug will proceed more quickly than learning that is paired with a placebo. Functional magnetic resonance imaging will be used to assess the effect of the drug on cortical plasticity, by comparing the pre-training versus post-training brain activation changes that are caused by learning the visual task while on the drug against those caused by learning the task on placebo. If this new method of enhancing plasticity should turn out to be successful, it will provide fundamentally important and novel knowledge about the nature of plasticity in the adult human brain, and could also lead to a wide range of potential clinical and practical applications. Understanding how brain plasticity works in adult humans is of critical importance, because recent research suggests that plasticity can be capitalized upon in order to remediate neurological problems, such as movement disorders resulting from stroke or from repetitive strain injury, and reading and language disorders.