Sensorimotor transformations in phonological working memory

 描述（由申请人提供）：拟议的研究将调查语音短期记忆期间言语的听觉和发音神经表征之间的感觉运动转换。这种转换，这也是必不可少的语音反馈控制错误纠正，语音发展，和简单的重复，被认为是发生在区Spt（Sylvian-parietal-temporal）占主导地位的后颞平面，但详细的神经机制尚未完全阐明和最近的双半球感觉运动整合的索赔。在这项研究中，高密度直接皮层记录，或皮层电图（ECoG），将获得从大脑侧裂周围额叶，顶叶，颞叶清醒，行为的人。这些受试者正在接受手术治疗难治性癫痫，植入电极定位癫痫灶。本研究采用多种行为学和计算学的方法，对语音短时记忆中的感觉运动转换进行定位，并确定这些转换的机制。在重复任务期间，受试者将在听觉上呈现可变负载的单词和伪单词（范围从1到9个音节），或频谱匹配的非语音声音。在可变长度的延迟期（范围2至15秒）后，受试者将被提示公开重复刺激。时间锁定的ECoG信号的谱时分析将识别涉及的皮层区域和激活的层级序列。功能连接和定向传递函数分析将探索皮层区域之间的相互作用，并检验“语音回路”是语音信息短期维持的基础这一假设。行为参数（表现）、实验参数（刺激负荷、延迟持续时间、单词与伪单词与非语音）和神经参数（激活强度、皮层网络连接性、信息流方向性）之间的神经行为相关性将识别出参与语音信息维持的那些皮层区域。通过分析具有高时间分辨率的神经状态空间轨迹，我们将测试语音感觉运动转换的假设机制。在语音回路的背景下阐明感觉运动整合的神经机制将增加我们对大脑如何以及在何处执行这一重要转换的知识。这将有助于更好地了解疾病 例如传导性失语症和发育性口吃，它们被认为是感觉运动整合障碍。此外，理解这种转变可能会导致更好的基于语音的脑机接口的开发。

 DESCRIPTION (provided by applicant): The proposed study will investigate the sensorimotor transformation between auditory and articulatory neural representations of speech during phonological short-term memory. This transformation, which is also essential in speech feedback control for error correction, speech development, and simple repetition, is thought to occur in area Spt (Sylvian-parietal-temporal) of the dominant posterior planum temporale, however the detailed neural mechanisms have not been fully elucidated and a recent claim for bi-hemispheric sensorimotor integration as been made. In this study, high-density direct cortical recordings, or electrocorticography (ECoG), will be obtained from the peri-Sylvian frontal, parietal, and temporal lobes in awake, behaving humans. These subjects are undergoing surgical treatment for medically refractory epilepsy with electrodes implanted for seizure foci localization. By employing multiple behavioral and computational approaches, this study will 1) localize sensorimotor transformations in phonological short-term memory and 2) determine the mechanism of these phonological sensorimotor transformations. During a repetition task, subjects will be acoustically presented with words and pseudo-words of variable load (ranging from 1 to 9 syllables), or spectrally matched non-speech sounds. After a delay period of variable length (range 2 to 15 seconds), subjects will be cued to overtly repeat the stimulus. Spectrotemporal analysis of lime-locked ECoG signals will identify cortical areas involved and tier sequence of activation. Functional connectivity and directed transfer function analysis will explore interactions between cortical areas and test the hypothesis that a `phonological loop' underlies short- term maintenance of phonologic information. Neurobehavioral correlations between behavioral parameters (performance), experimental parameters (stimulus load, delay duration, word versus pseudo-word versus non- speech), and neural parameters (activation strength, cortical network connectivity, information flow directionality) will identify those cortial areas involved in maintenance of phonologic information. By analyzing neural state-space trajectories with high temporal resolution we will test a hypothesized mechanism for phonological sensorimotor transformation. Elucidating the neural mechanisms of sensorimotor integration in the context of the phonological loop will add to our knowledge of how and where the brain performs this vital transformation. This will lead to a better understanding of disorders such as conductive aphasia and developmental stuttering, which are thought to be disorders of sensorimotor integration. Additionally, understanding this transformation may lead to development of better speech-based brain-computer interfaces.