Investigating output modality for a brain-computer interface for communication

描述（由申请人提供）：脑机接口（bci）越来越多地用于重度残疾患者的科学研究和治疗干预应用。这种设备的典型用途是通过记录头皮（脑电图）、脑表面（皮质电图）或大脑内部（皮质内微电极记录）的大脑活动，提供对计算机光标和/或离散项目的连续控制。作为治疗设备，脑机接口在恢复瘫痪和哑巴患者的沟通能力方面非常成功，最常见的是通过离散选择字母拼写。在一项研究中，BCI采用实时控制语音合成器进行通信。然而，这项研究依赖于侵入性神经记录，这对于广泛的语言治疗应用是不切实际的。拟议的项目通过研究BCI的性能来解决这一知识差距，该BCI被设计用于将非侵入性EEG感觉运动节律映射到低维语音表示中，特别是形成峰频率，用于控制具有瞬时听觉和视觉反馈的连续元音合成器。一个原型装置已经被开发出来，并被一个试验者用来控制二维形成峰频率元音合成器。该设备将用于人类受试者研究，用于评估BCI在元音生成任务中的表现，以解决两个主要研究课题：[1]反馈方式（听觉与视觉）对学习BCI控制的影响，[2]调查使用BCI设备的长期保持性能。本研究的目的是为了说明有意义的听觉反馈（即元音声音）作为语音脑机接口的适当反馈机制的可行性。这项技术最终将使严重沟通障碍的患者受益，特别是对那些侵入性脑机接口不可行的患者。本研究结果也将为未来使用低维语音合成器设计脑机接口（BCI）提供基础，以使用无创脑电图连续产生辅音和元音。长期的研究目标是提供连续的人工语音（包括元音和辅音）实时合成，以恢复沟通，这将是我们提高患者生活质量和使他们更好地参与社会互动能力的重大进步。

DESCRIPTION (provided by applicant): Brain-computer interfaces (BCIs) are increasingly being used in both scientific research and therapeutic intervention applications for severely disabled patients. Typical usage of such devices provides continuous control over computer cursors and/or selection of discrete items using brain activity recorded from the scalp (electroencephalography), on the brain surface (electrocorticography), or inside the brain (intracortical microelectrode recording). As therapeutic devices, BCIs have been very successful in restoring communication abilities to paralyzed and mute patients, most often by discrete-choice letter spelling. In one study, real-time control of a speech synthesizer was employed for communication by BCI. However, this study relied on invasive neurological recordings, which is impractical for widespread speech therapeutic application. The proposed project addresses this knowledge gap by investigating performance of a BCI designed to map non- invasive EEG sensorimotor rhythms into a low-dimensional speech representation, specifically formant frequencies, for control of a continuous vowel synthesizer with instantaneous auditory and visual feedback. A prototype device has been developed and used by a pilot subject to control a two dimensional formant frequency vowel synthesizer. This device will be used in a human subjects study for evaluation of BCI performance in vowel production tasks to address two major research topics: [1] the effect of feedback modality (auditory vs. visual) on learning BCI control and [2] investigating long-term retention of performance using the BCI device. The goal of this research study is to illustrate the feasibility of meaningful auditory feedback (i.e. vowel sounds) as an appropriate feedback mechanism for a speech BCI. This technology will ultimately benefit patients with severe communication impairment, especially for those whom invasive BCIs are not viable options. The results of this research will also provide a basis for future BCI designs using low- dimensional speech synthesizers for continuous production of both consonants and vowels using non-invasive EEG. The long-term research goal, of providing continuous artificial speech (both vowels and consonants) synthesis in real-time for restoration of communication, will be a significant advance in our ability to improve the patients' quality of life and allow them to better engage in social interactions. PUBLIC HEALTH RELEVANCE: The proposed research will improve our understanding of the feedback control mechanisms required for optimal communication using a brain-computer interface. The outcome of this research has the potential to improve the quality of life for mute, paralyzed patients, or others lacking the ability to speak and help inform development of improved brain-computer interface applications for communication.