Learning of New Sound Categories Shapes Neural Response Patterns in Human Auditory Cortex
Learning of New Sound Categories Shapes Neural Response Patterns in Human Auditory Cortex
复制标题
DOI：
10.1523/jneurosci.0584-12.2012
复制
发表时间：
2012-09-19
影响因子：
5.3
通讯作者：
Formisano, Elia
中科院分区：
文献类型：
--
作者：
Ley, Anke;Vroomen, Jean;Formisano, Elia
新的声音类别的形成是日常目标导向行为的基础。分类需要根据上下文和任务的要求从连续的物理特征中抽象出离散的类。动物的电生理学已经表明，学习对新的声音进行分类会改变它们在早期听觉皮层水平上的时空神经表征。然而，功能磁共振成像（fMRI）的研究，到目前为止还没有得到深入了解的影响类别学习的声音表征在人类听觉皮层。这可能是由于使用过度学习的语音类类别和功能磁共振成像减法范例，导致灵敏度不足，以区分学习引起的，新的声音类别的反应。在这里，我们使用功能磁共振成像模式分析，研究人类听觉皮层反应模式的变化引起的类别学习。我们创造了复杂的新的声音类别和分析分布式激活模式在被动听一个声音连续体之前和之后的类别学习。我们表明，只有经过训练，声音类别才能从早期听觉区域成功解码，并且学习引起的模式变化是特定于类别独特的声音特征（即，pitch）。值得注意的是，声音连续体的功能磁共振成像反应模式之间的相似性反映了行为类别识别功能的S形。我们的研究结果表明，新的声音类别的感知表征出现在人类听觉处理层次的早期水平的神经变化。
The formation of new sound categories is fundamental to everyday goal-directed behavior. Categorization requires the abstraction of discrete classes from continuous physical features as required by context and task. Electrophysiology in animals has shown that learning to categorize novel sounds alters their spatiotemporal neural representation at the level of early auditory cortex. However, functional magnetic resonance imaging (fMRI) studies so far did not yield insight into the effects of category learning on sound representations in human auditory cortex. This may be due to the use of overlearned speech-like categories and fMRI subtraction paradigms, leading to insufficient sensitivity to distinguish the responses to learning-induced, novel sound categories. Here, we used fMRI pattern analysis to investigate changes in human auditory cortical response patterns induced by category learning. We created complex novel sound categories and analyzed distributed activation patterns during passive listening to a sound continuum before and after category learning. We show that only after training, sound categories could be successfully decoded from early auditory areas and that learning-induced pattern changes were specific to the category-distinctive sound feature (i.e., pitch). Notably, the similarity between fMRI response patterns for the sound continuum mirrored the sigmoid shape of the behavioral category identification function. Our results indicate that perceptual representations of novel sound categories emerge from neural changes at early levels of the human auditory processing hierarchy.