Role of the striatum in incidental learning of sound categories
Role of the striatum in incidental learning of sound categories
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DOI：
10.1073/pnas.1811992116
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发表时间：
2019-03-05
影响因子：
11.1
通讯作者：
Holt, Lori L.
中科院分区：
文献类型：
--
作者：
Lim, Sung-Joo;Fiez, Julie A.;Holt, Lori L.
人类生来就是“通用听众”，对任何特定语言没有偏见。然而，在生命的第一年，婴儿的感知是通过学习母语语音类别而形成的。声学上不同的声音——例如不同说话者发出的同一个词——在功能上被视为等同。在自然环境中，这些类别通常是偶然出现的，没有明显的分类或明确的反馈。然而，类别学习的神经基础几乎完全使用带有关于分类决策的明确反馈的公开分类任务来研究。在这里，我们检查了先前参与类别学习的纹状体是否有助于偶然获得声音类别。在功能磁共振成像扫描仪中，参与者玩了一个视频游戏，其中声音类别范例与游戏动作和事件一致，允许声音类别顺便支持成功的游戏。实验组听到从连贯的类别空间中提取的非语音样本，而对照组则听到从结构化程度较低的空间中提取的声学上相似的声音。尽管各组在游戏中表现相似，但实验组声音类别学习的泛化和后纹状体的激活明显高于对照组。此外，实验组显示出与所有类别的概括相关的大脑行为关系，而在对照组中，这些关系仅限于具有结构化声音分布的类别。总之，这些结果表明，纹状体通过与左颞上沟的相互作用，有助于偶然获得从自然学习环境中出现的声音类别表征。
Humans are born as "universal listeners" without a bias toward any particular language. However, over the first year of life, infants' perception is shaped by learning native speech categories. Acoustically different sounds-such as the same word produced by different speakers-come to be treated as functionally equivalent. In natural environments, these categories often emerge incidentally without overt categorization or explicit feedback. However, the neural substrates of category learning have been investigated almost exclusively using overt categorization tasks with explicit feedback about categorization decisions. Here, we examined whether the striatum, previously implicated in category learning, contributes to incidental acquisition of sound categories. In the fMRI scanner, participants played a videogame in which sound category exemplars aligned with game actions and events, allowing sound categories to incidentally support successful game play. An experimental group heard nonspeech sound exemplars drawn from coherent category spaces, whereas a control group heard acoustically similar sounds drawn from a less structured space. Although the groups exhibited similar in-game performance, generalization of sound category learning and activation of the posterior striatum were significantly greater in the experimental than control group. Moreover, the experimental group showed brain-behavior relationships related to the generalization of all categories, while in the control group these relationships were restricted to the categories with structured sound distributions. Together, these results demonstrate that the striatum, through its interactions with the left superior temporal sulcus, contributes to incidental acquisition of sound category representations emerging from naturalistic learning environments.