Generalized Perceptual Learning in the Absence of Sensory Adaptation
Generalized Perceptual Learning in the Absence of Sensory Adaptation
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DOI：
10.1016/j.cub.2012.07.059
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发表时间：
2012-10-09
期刊：
影响因子：
9.2
通讯作者：
Sagi, Dov
中科院分区：
文献类型：
--
作者：
Harris, Hila;Gliksberg, Michael;Sagi, Dov
重复执行视觉任务会导致对训练刺激的长期敏感性增加，这种现象称为感知学习。视觉学习的一个普遍属性是特异性：在训练期间获得的性能改善仅适用于训练的刺激特征，这些特征被认为是在感觉脑区域中编码的[1-3]。然而，最近的结果显示，随着训练期内试验次数的增加，性能下降[4，5]。这种选择性的敏感性降低被认为是由于感觉适应引起的[5，6]。在这里，我们使用标准的纹理辨别任务[7]表明，位置特异性是感觉适应的结果;也就是说，它是由于重复刺激导致的选择性降低敏感性的结果。观察者练习纹理任务，目标呈现在背景纹理内的一个固定位置。为了消除适应，我们添加了任务无关（“虚拟”）试验，其中纹理相对于目标方向定向为45，已知可以抵消适应[8]。结果表明，与标准范式的位置特异性，但完全泛化到一个新的位置时，适应被删除。我们认为，适应干扰不变的模式识别学习诱导网络依赖的变化，在当地的视觉表征。
Repeated performance of visual tasks leads to long-lasting increased sensitivity to the trained stimulus, a phenomenon termed perceptual learning. A ubiquitous property of visual learning is specificity: performance improvement obtained during training applies only for the trained stimulus features, which are thought to be encoded in sensory brain regions [1-3]. However, recent results show performance decrements with an increasing number of trials within a training session [4, 5]. This selective sensitivity reduction is thought to arise due to sensory adaptation [5, 6]. Here we show, using the standard texture discrimination task [7], that location specificity is a consequence of sensory adaptation; that is, it results from selective reduced sensitivity due to repeated stimulation. Observers practiced the texture task with the target presented at a fixed location within a background texture. To remove adaptation, we added task-irrelevant ("dummy") trials with the texture oriented 45 relative to the target's orientation, known to counteract adaptation [8]. The results indicate location specificity with the standard paradigm, but complete generalization to a new location when adaptation is removed. We suggest that adaptation interferes with invariant pattern-discrimination learning by inducing network-dependent changes in local visual representations.