Rao Nishant, Ostry David J
Yale Child Study Center, Yale School of Medicine, Yale University, New Haven, Connecticut, United States.
Department of Psychology, McGill University, Montreal, Quebec, Canada.
J Neurophysiol. 2025 Feb 1;133(2):479-489. doi: 10.1152/jn.00337.2024. Epub 2024 Dec 31.
Our knowledge of human sensorimotor learning and memory is predominantly based on the visuospatial workspace and limb movements. Humans also have a remarkable ability to produce and perceive speech sounds. We asked whether the human speech-auditory system could serve as a model to characterize the retention of sensorimotor memory in a workspace that is functionally independent of the visuospatial one. Using adaptation to altered auditory feedback, we investigated the durability of a newly acquired speech-acoustical memory (8- and 24-h delay), its sensitivity to the manner of acquisition (abrupt vs. gradual perturbation), and factors affecting memory retrieval. We observed extensive retention of learning (∼70%) but found no evidence for offline gains. The speech-acoustical memory was insensitive to the manner of its acquisition. To assess factors affecting memory retrieval, tests were first done in the absence of auditory feedback (with masking noise). Under these conditions, it appeared there was no memory for prior learning as if after an overnight delay, speakers had returned to their habitual speech production modes. However, when speech was reintroduced, resulting in speech error feedback, speakers returned immediately to their fully adapted state. This rapid switch shows that the two modes of speech production (adapted and habitual) can coexist in parallel in sensorimotor memory. The findings demonstrate extensive persistence of speech-acoustical memory and reveal context-specific memory retrieval processes in speech-motor learning. We conclude that the human speech-auditory system can be used to characterize sensorimotor memory in a workspace that is distinct from the visuospatial workspace. There is extensive retention of speech-motor learning. Two parallel modes exist in speech motor memory, one with access to everyday habitual speech and the other with access to newly learned speech-acoustical maps. The availability of speech error feedback triggers a switch between these two modes. Properties of sensorimotor memory in the human speech-auditory system are behaviorally similar to, but functionally independent of, their visuospatial counterparts.
我们对人类感觉运动学习和记忆的了解主要基于视觉空间工作区和肢体运动。人类在产生和感知语音方面也具有非凡的能力。我们探讨了人类语音听觉系统是否可以作为一个模型，用于表征在功能上独立于视觉空间工作区的工作空间中感觉运动记忆的保持情况。通过对改变后的听觉反馈进行适应，我们研究了新获得的语音声学记忆的持久性（8小时和24小时延迟）、其对获取方式（突然与逐渐扰动）的敏感性以及影响记忆检索的因素。我们观察到学习的广泛保持（约70%），但没有发现离线增益的证据。语音声学记忆对其获取方式不敏感。为了评估影响记忆检索的因素，首先在没有听觉反馈（有掩蔽噪声）的情况下进行测试。在这些条件下，似乎没有对先前学习的记忆，就好像经过一夜延迟后，说话者又回到了他们习惯的语音产生模式。然而，当重新引入语音，从而产生语音错误反馈时，说话者立即回到了他们完全适应的状态。这种快速切换表明，两种语音产生模式（适应的和习惯的）可以在感觉运动记忆中并行共存。这些发现证明了语音声学记忆的广泛持久性，并揭示了语音运动学习中特定于上下文的记忆检索过程。我们得出结论，人类语音听觉系统可用于表征与视觉空间工作区不同的工作空间中的感觉运动记忆。语音运动学习有广泛的保持。语音运动记忆中存在两种并行模式，一种可访问日常习惯语音，另一种可访问新学习的语音声学图谱。语音错误反馈的可用性触发了这两种模式之间的切换。人类语音听觉系统中感觉运动记忆的特性在行为上与其视觉空间对应物相似，但在功能上是独立的。
