Ohl F W, Scheich H, Freeman W J
Leibniz-Institut für Neurobiologie, Brenneckstrasse 6, D-39118 Magdeburg, Germany.
Nature. 2001 Aug 16;412(6848):733-6. doi: 10.1038/35089076.
Humans are able to classify novel items correctly by category; some other animals have also been shown to do this. During category learning, humans group perceptual stimuli by abstracting qualities from similarity relationships of their physical properties. Forming categories is fundamental to cognition and can be independent of a 'memory store' of information about the items or a prototype. The neurophysiological mechanisms underlying the formation of categories are unknown. Using an animal model of category learning, in which frequency-modulated tones are distinguished into the categories of 'rising' and 'falling' modulation, we demonstrate here that the sorting of stimuli into these categories emerges as a sudden change in an animal's learning strategy. Electro-corticographical recording from the auditory cortex shows that the transition is accompanied by a change in the dynamics of cortical stimulus representation. We suggest that this dynamic change represents a mechanism underlying the recognition of the abstract quality (or qualities) that defines the categories.
人类能够正确地按类别对新事物进行分类；其他一些动物也已被证明有此能力。在类别学习过程中，人类通过从其物理属性的相似关系中提取特征来对感知刺激进行分组。形成类别是认知的基础，并且可以独立于关于这些事物的信息的“记忆库”或原型。类别形成背后的神经生理机制尚不清楚。我们使用一种类别学习的动物模型，其中调频音调被区分为“上升”和“下降”调制类别，在此证明，将刺激分类到这些类别中表现为动物学习策略的突然变化。来自听觉皮层的皮层电图记录表明，这种转变伴随着皮层刺激表征动态的变化。我们认为，这种动态变化代表了识别定义类别的抽象特征的一种机制。
