Learning and Adaptation in Primary Visual Cortex

描述(申请人提供)：这项建议的目标是调查学习和适应可以改变初级视觉皮质神经元的定向调节的机制。研究表明，学会辨别条形取向的微小变化可以锐化其择优取向在条形取向附近的细胞的取向调谐曲线，而适应取向栅会加宽调谐曲线，并使其择优取向接近适应取向的细胞的调谐曲线峰位移动。了解这些现象将有助于我们对神经元处理的理解，这将在21世纪的临床和基础神经科学中发挥关键作用。具体目标1的目标是确定修改皮质内连接是否对于模拟学习和适应是必要的和充分的，在网络中，来自外侧膝状体的前馈输入被尖锐地调整为定向，并将通过建立过去的建模工作来实现。具体目标2的目的是从实验上测试这一预测，即清醒、非麻醉的受试者的适应会导致生理变化，而生理变化是学习过程中所见变化的短暂版本。

DESCRIPTION (provided by applicant): The goal of this proposal is to investigate the mechanism by which learning and adaptation can alter the orientation tuning of neurons in primary visual cortex. Learning to discriminate small changes in the orientation of a bar has been shown to sharpen the orientation tuning curves of cells whose preferred orientation is near the bar's orientation, while adapting to an oriented grating has been shown to broaden the tuning curves and shift the tuning curve peaks of cells whose preferred orientation is near the adapted orientation. Understanding these phenomena will contribute to our understanding of neuronal processing, which will play a critical role in both clinical and basic neuroscience in the twenty-first century. The goal of Specific Aim 1 is to determine whether modifying intracortical connections is necessary and sufficient for simulating learning and adaptation in a network where the feed-forward input from the lateral geniculate nucleus is sharply tuned for orientation, and will be accomplished by building on past modeling efforts. The goal of Specific Aim 2 is to experimentally test the prediction that adaptation in alert, non-anesthetized subjects causes physiological changes that are a transient version of the changes seen in learning.