Sensorimotor adaptation as a window to speech movement planning

说话通常被认为是一个由两部分组成的过程。首先，语言规划系统将想法、概念和/或单词转换为一系列较小的单位，如音节或语音。这些基本的语言单位然后被认为是由一个单独的运动规划系统“读出”成发音动作。然而，这种分开的计划过程不能解释现实世界中的言语产生，因为它可以学习依赖于语言环境的言语运动的变化。例如，如果你从加利福尼亚州搬到威斯康星州，你可能会学到一种新的口音：你可能会不知不觉地开始说“Bag”，用的是“say”中的元音，而不是“sat”中的元音。如果这个发音在所有单词中都发生了相同的变化(“Snag”、“Dragon”、“agma”)，这将表明你学习了一个较小的单位(“ag”)的变化。然而，你可能会改变说“Bag”的方式，同时保留原来的“bagpiong”发音，这意味着学习要依赖于单词的上下文。本研究的目的是了解语言语境何时影响学习以及何时不影响学习，并利用这些结果来确定不同语境下言语运动规划的广度。更准确地描述言语运动规划对于了解我们通常是如何说话的，以及这个过程是如何在神经障碍中分解的至关重要的，这些神经障碍损害了我们规划言语运动的方式，例如失语症和言语失用症。调查人员参与了《青年思维前沿》杂志，该杂志旨在通过让下一代科学家(8-15岁的儿童)参与同行审查过程来吸引他们。他们将在一年一度的威斯康星州科学节上举办现场演示，并将为麦迪逊地区的孩子们提供动手科学体验，作为暑期和课后计划的一部分。为了研究语音运动是如何计划的，研究人员将使用一项导致发音无意识变化的语音学习任务。参与者将对着麦克风说话，同时听到他们的声音随着特定频率的变化而回放，使一个元音听起来像另一个元音(例如，Bed可以被改变成像“Bad”一样的发音)。随着时间的推移，这会导致参与者在不知不觉中改变他们的元音发音方向。重要的是，参与者可以同时学习根据一个元音出现的单词以不同的方式改变它的发音(例如，即使它们有相同的元音发音，发音也不同)。这表明，词的语境可以区分这个元音的发音规划。研究人员将测试其他语言环境，这些环境可能会让参与者学习“相同”语音的不同发音，如词义、短语结构、音调或语调，以及说话时的手势(例如，指点)。如果这种学习是可能的，它表明这些背景是说话运动计划的一部分，共同形成了一个可以支撑学习的凝聚力单元。这项工作将确定言语运动规划如何整合语言表达和其他交流动作，如音调和手势。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Speaking is normally thought of as a two-part process. First, a language planning system transforms ideas, concepts, and/or words into a series of smaller units, such as syllables or speech sounds. These basic linguistic units are then thought to be “read out” into articulatory movements by a separate motor planning system. However, this divided planning process cannot explain speech production in the real world, because it is possible to learn changes to speech movements that are dependent on language context. For example, if you move from California to Wisconsin, you may learn a new accent: you may unconsciously start saying “bag” with the vowel sound in “say” instead of the vowel sound in “sat”. If the same change occurred in all words with this sound (“snag”, “dragon”, “agriculture”), it would suggest you learned a change to the smaller unit (“ag”). However, you might change the way you say “bag” while keeping your old pronunciation of “bagpipe”, suggesting learning that is dependent on word context. The purpose of this research is to understand when linguistic context influences learning and when it does not and to use those results to determine the span of speech motor planning in different contexts. A more accurate characterization of speech motor planning is critical for understanding how we typically speak and how this process breaks down in neurological disorders that impair the way we plan speech movements, such as aphasia and apraxia of speech. The investigators are involved with Frontiers for Young Minds, a journal that aims to engage the next generation of scientists (kids ages 8-15) by involving them in the peer review process. They will host live demonstrations at the yearly Wisconsin Science Festival, and will provide hands-on science experiences as a part of summer and afterschool programming for Madison-area kids. To investigate how speech movements are planned, the investigators will use a speech learning task that causes an unconscious change to pronunciation. Participants will talk into a microphone while hearing playback of their voice with certain frequencies shifted, making one vowel sound like another (for example, “bed” could be shifted to sound like “bad”). Over time, this causes participants to unknowingly shift their vowel pronunciation in the opposite direction. Importantly, participants can simultaneously learn to shift a single vowel sound in different ways based on the word in which it appears (for example, pronouncing “bed” and “head” differently, even though they share the same vowel sound). This shows that the word context can differentiate planning of this vowel sound. The investigators will test other linguistic contexts that might allow participants to learn different pronunciations for the “same” speech sound, contexts such as word meaning, phrase structure, pitch or intonation, and gesturing while speaking (for example, pointing). If this learning is possible, it suggests that these contexts are part of the movement plans for speaking, together forming a cohesive unit that can scaffold learning. The work will establish how speech motor planning integrates linguistic representation and other communicative movements such as pitch and gesture.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.