A kinematic study of phonetic reduction in American Sign Language

描述（由申请人提供）：本研究旨在研究美国手语（ASL）中习惯性和自发的手语降低，这是在流利的手语中出现的语音降低形式。虽然一个符号在身体上的位置是一个音系参数，将其与其他符号区分开来，但在语音层面上，位置是非常可变的。例如，在引用形式中，在前额或太阳穴产生的特殊符号通常在流利的签名中降低到语音上不同的位置（例如，下巴）。当签名速度或协发音压力增加时，位于前额或太阳穴的其他标志也会自发地降低。本研究的目的是比较两种现象，即习惯性的和自发的符号降低，并分析其发生的频率，以及它们的物理程度和形状对语速和语音语境的影响。运动学数据将从本地ASL手语者收集，因为他们产生的标志，位于额头或太阳穴引用形式。通过控制手语的速度和语境，增加习惯性手语和自发手语的发生和程度。我们认为，语音降低的发生和程度都受到一个符号的发音结构的影响，这就是为什么一个符号可以被降低，但仍然可以被理解为同一个符号。特别是，根据已有记录的常规手势下降的具体案例，我们预测，具有简单路径运动到头部的手势将移动到头部的较低位置，而包含额外的符号内部运动的手势将与头部分离，并在身体前方的手势空间中产生。本研究在发音音韵学的框架下研究手语，目的是理解发音目标和手势在手势模态中的本质。

DESCRIPTION (provided by applicant): The proposed study seeks to examine conventionalized and spontaneous sign lowering in American Sign Language (ASL), which are forms of phonetic reduction that occur in fluent signing. Although a sign's location on the body is a phonological parameter that differentiates it from other signs, location can be extremely variable at a phonetic level. For instance, particular signs that are produced at the forehead or temple in citation form are conventionally lowered in fluent signing to phonologically-distinct locations (e.g., the jaw). Lowering also occurs spontaneously in other signs located at the forehead or temple, when there is increased signing speed or coarticulatory pressure. The goal of this study is to compare these two phenomena, conventionalized and spontaneous sign lowering, and analyze the frequency of their occurrence and their physical extent and shape as an effect of speed and phonetic context. Kinematic data will be collected from native ASL signers as they produce signs that are located at the forehead or temple in citation form. Signing speed and sign context will be manipulated in order to increase the occurrence and extent of both conventionalized and spontaneous sign lowering. We propose that both the occurrence and extent of phonetic lowering are influenced by a sign's articulatory structure, and this is what allows a sign to be lowered and yet remain intelligible as the same sign. In particular, based on the specific cases of conventionalized sign lowering that have been documented, we predict that signs with a simple path movement to the head will move to lower locations on the head, whereas signs that include an additional sign-internal movement will become dissociated from the head and be produced in the signing space in front of the body. This study examines signed language within the framework of articulatory phonology, with the aim of understanding the nature of articulatory targets and gestures in the sign modality. Project Narrative: This study is relevant to NIH's public health mission, because it contributes to the development of physiologically-based measures of sign production and perception, which in turn will help differentiate normal phonetic variation in sign production from variation due to language or motor disorders in Deaf signers. Further, it provides a unique context for analyzing targeted limb movements, which is relevant to the understanding of human motor disorders.