Signal but not noise changes with perceptual learning
Signal but not noise changes with perceptual learning
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DOI：
10.1038/46027
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发表时间：
1999-11-11
期刊：
影响因子：
64.8
通讯作者：
Sekuler, AB
中科院分区：
文献类型：
--
作者：
Gold, J;Bennett, PJ;Sekuler, AB
知觉辨别力随着练习而提高。这种“感知学习”通常是特定于训练过程中出现的刺激（1-5）：表明练习可能会改变皮层感觉神经元的反应特征（6，7）。虽然我们对学习如何改变大脑皮层回路已经有了很多了解，但这些变化与行为的关系仍不清楚。不同的理论认为，实践通过增强信号（1，9，10）或减少内部噪声（11，12）或两者兼而有之（13）来提高辨别力。在这里，为了区分这些替代品，我们制作了一组信号强度可以变化的面部和纹理，我们训练观察者识别嵌入噪声中的这些模式。在几天的几个会话中，性能提高了400%。将人类的表现与一个理想的观察者的表现进行比较，结果表明，学习提高了观察者对任务相关信息进行编码的效率。观察者反应的一致性，通过双通技术测量，其中相同的刺激在每个实验会话中显示两次（14，15），在训练期间没有改变，表明学习对内部噪音没有影响。这些结果表明，知觉学习可以增强信号强度，并为学习理论提供了重要的限制。
Perceptual discrimination improves with practice. This 'perceptual learning' is often specific to the stimuli presented during training(1-5): indicating that practice may alter the response characteristics of cortical sensory neurons(6,7). Although much is known about how learning modifies cortical circuits(8), it remains unclear how these changes relate to behaviour. Different theories assume that practice improves discrimination by enhancing the signal(1,9,10) diminishing internal noise(11,12) or both(13). Here, to distinguish among these alternatives, we fashioned sets of faces and textures whose signal strength could be varied, and we trained observers to identify these patterns embedded in noise. Performance increased by up to 400% across several sessions over several days. Comparisons of human performance to that of an ideal discriminator showed that learning increased the efficiency with which observers encoded task-relevant information. Observer response consistency, measured by a double-pass technique in which identical stimuli are shown twice in each experimental session(14,15), did not change during training, showing that learning had no effect on internal noise. These results indicate that perceptual learning may enhance signal strength, and provide important constraints for theories of learning.