A listener's interpretation of a given speech sound can vary probabilistically from moment to moment. Previous experience (i.e., the contexts in which one has encountered an ambiguous sound) can further influence the interpretation of speech, a phenomenon known as perceptual learning for speech. This study used multivoxel pattern analysis to query how neural patterns reflect perceptual learning, leveraging archival fMRI data from a lexically guided perceptual learning study conducted by Myers and Mesite [Myers, E. B., & Mesite, L. M. Neural systems underlying perceptual adjustment to non-standard speech tokens. Journal of Memory and Language, 76, 80–93, 2014]. In that study, participants first heard ambiguous /s/–/∫/ blends in either /s/-biased lexical contexts (epi_ode) or /∫/-biased contexts (refre_ing); subsequently, they performed a phonetic categorization task on tokens from an /asi/–/a∫i/ continuum. In the current work, a classifier was trained to distinguish between phonetic categorization trials in which participants heard unambiguous productions of /s/ and those in which they heard unambiguous productions of /∫/. The classifier was able to generalize this training to ambiguous tokens from the middle of the continuum on the basis of individual participants' trial-by-trial perception. We take these findings as evidence that perceptual learning for speech involves neural recalibration, such that the pattern of activation approximates the perceived category. Exploratory analyses showed that left parietal regions (supramarginal and angular gyri) and right temporal regions (superior, middle, and transverse temporal gyri) were most informative for categorization. Overall, our results inform an understanding of how moment-to-moment variability in speech perception is encoded in the brain.

听者对给定语音声音的解释可能随时变化。先前的经验（即，遇到模糊声音的上下文）可以进一步影响语音的解释，这种现象被称为语音感知学习。本研究使用多体素模式分析来查询神经模式如何反映感知学习，利用来自 Myers 和 Mesite 进行的词汇引导感知学习研究的存档 fMRI 数据 [Myers, EB, & Mesite, LM 神经系统对非标准语音进行感知调整令牌。轴颈记忆和语言的，76，80-93，2014]。在该研究中，参与者首先听到模糊的 /s/–/∫/ 混合在 /s/-biased 词汇上下文中（epi_ ode ) 或 /∫/-biased 上下文 ( refre_ing); 随后，他们对 /asi/–/a∫i/ 连续体中的标记执行了语音分类任务。在当前的工作中，训练了一个分类器来区分参与者听到明确的 /s/ 产生式和那些他们听到明确的 /∫/ 产生式的语音分类试验。分类器能够根据个体参与者的逐次试验感知，将这种训练推广到连续统中间的模糊标记。我们将这些发现作为语音感知学习涉及神经重新校准的证据，因此激活模式接近感知类别。探索性分析显示左侧顶叶区域（缘上回和角回）和右侧颞叶区域（上、中、和横向颞回）对分类最有用。总体而言，我们的结果有助于理解语音感知的瞬间变化是如何在大脑中编码的。