Perceptual learning serves as a mechanism for listeners to adapt to novel phonetic information. Distributional tracking theories posit that this adaptation occurs as a result of listeners accumulating talker-specific distributional information about the phonetic category in question (Kleinschmidt & Jaeger, Psychological Review, 122, 148–203, 2015). What is not known is how listeners build these talker-specific distributions—that is, if they aggregate all information received over a certain time period, or if they rely more heavily upon the most recent information received and down-weight older, consolidated information. In the present experiment, listeners were exposed to four interleaved blocks of a lexical decision task and a phonetic categorization task in which the lexical decision blocks were designed to bias perception in opposite directions of a “s”–“sh” contrast. Listeners returned several days later and completed the identical task again. In each individual session, listener’s perception of a “s”–“sh” contrast was biased by the information in the immediately preceding lexical decision block (though only when participants heard the “sh”-biasing block first, which was likely driven by stimulus characteristics). There was evidence that listeners accrued information about the talker over time since the bias effect diminished in the second session. In general, results suggest that listeners initially maintain some flexibility with their talker-specific phonetic representations, but over the course of several exposures begin to consolidate these representations.

感知学习是听众适应新语音信息的一种机制。分布跟踪理论认为，这种适应是由于听众积累了有关语音类别的特定于说话者的分布信息的结果（Kleinschmidt & Jaeger, Psychology Review , 122 , 148–203, 2015）。目前尚不清楚的是，听众如何构建这些特定于说话者的分布，也就是说，他们是否汇总在特定时间段内收到的所有信息，或者他们是否更依赖于收到的最新信息并降低较旧的综合信息的权重。在本实验中，听众接触到词汇决策任务和语音分类任务的四个交错块，其中词汇决策块被设计成在“s”-“sh”对比的相反方向上偏向感知。几天后，听众返回并再次完成相同的任务。在每个单独的会话中，听众对“s”-“sh”对比的感知受到前一个词汇决策块中信息的偏差（尽管只有当参与者首先听到“sh”偏差块时，这可能是由刺激驱动的特征）。有证据表明，由于偏见效应在第二次会议中减弱，随着时间的推移，听众逐渐积累了有关演讲者的信息。总的来说，结果表明，听众最初对特定于说话者的语音表示保持一定的灵活性，但在几次暴露的过程中开始巩固这些表示。