用于alpha波调制的毫秒级实时解码神经反馈系统

EEG-based neural feedback is one of the most important neural modulation techniques for enhancement of perceptual and cognitive functions and for rehabilitation of mental impairments. The effect of existing neural feedback techniques heavily depends on the user's autonomous control and the degree of their training, so that their real-time capability, precision, and applicability are limited. Neuroscientific evidence has shown that the amplitude and the phase of the alpha wave can modulate specific perception function, while the visual and auditory stimulus can also modulate the amplitude and phase of the alpha wave. Therefore, if we can deliver a visual or auditory stimulus at a specific alpha wave phase angle based on real-time estimation of the dynamic evolution of the alpha wave, then the amplitude and phase of alpha wave can more precisely modulated to achieve the goal of precise regulation of human brain perception function. In this project, we propose to design a millisecond-precision real-time decoded neural feedback system with precise and adaptive alpha wave modulation. Specifically, we will firstly study the alpha dynamics using neural mass model and develop a suitable strategy for modulation of the amplitude and phase of alpha wave. Secondly, we will build a hardware and software platform for real-time alpha wave decoding and feedback. Finally, we will carry out new experiments, where visual or auditory stimuli will be delivered at specific alpha wave phase angle (i.e., phase-locked stimulation), to validate the performance of the proposed system. The novel real-time decoded neural feedback technique will provide a more accurate and effective means for enhancement of cognitive performance and treatment of mental disorders.

基于脑电的神经反馈是实现感知功能增强与精神疾病康复的重要神经调控技术之一。现有神经反馈技术的效果依赖于受试者的自主调控能力以及训练程度，其实时性、精准性和适用性都有所欠缺。研究已发现alpha波的幅值相位会调制特定感知功能，并且视听觉刺激也会对alpha波形成调制。因此如能实时估计alpha波相位并据此在alpha波特定相位施加视听觉刺激，可实现对alpha波的准确调制以达到精准调控感知能力的目标。据此，本课题拟设计一款可精确自适应调制alpha波的毫秒级实时解码神经反馈系统。具体地，本课题拟通过神经集群模型研究alpha波动力学行为并提出对应调幅调相控制策略，同时搭建软硬件平台实现alpha波的毫秒级实时解码反馈，最后在实验中通过锁相刺激（在alpha波特定相位呈现刺激）对alpha波进行调制以验证系统效果。该新型实时解码神经反馈技术将为改善认知功能与治疗精神障碍提供更快速有效的手段。

研究背景：神经调控技术利用植入性或非植入性刺激手段来改变中枢神经、外周神经或自主神经系统活性，已达到改善患病人群的症状，提高生命质量的目的。目前，主要的神经调控技术包括基于非侵入式的经颅电/磁/超声刺激的脑刺激技术以及基于植入式电极的深度脑刺激技术。这两类技术都需要借助特殊的装置和设备对大脑进行直接的刺激，甚至是开颅手术，在实际的使用中会收到较大限制。为此，本课题发展了一套基于自然感觉通路施加刺激对脑电的节律信号进行调控的方法以突破传统神经调控技术的局限。..研究内容：首先根据神经动力学原理提出锁相反馈刺激的脑电节律调控策略；其次，设计实验、搭建软硬件平台验证了基于锁相反馈刺激的调控策略的有效性；最后，对不同脑区，不同节律、不同刺激模态的调控效果进行探索。..重要结果：本项目的最重要的研究成果在于实现了脑电信号中视觉区alpha节律的基于锁相反馈刺激的调控方式，其中包括：首先，在调控技术上发展出了一套实时解码反馈调控系统；其次，在调控策略上基于神经动力学机制提出了锁相反馈刺激的调控策略；第三，调控效果上实现了alpha波的幅值频率联合调制。..科学意义：本项目着重发展一套基于锁相反馈刺激的脑电节律调控手段。首先，该调控手段有别于传统的神经调控手段，可以通过自然感觉通路对脑电的节律信号进行调控，简便易行，且相关神经机制相对明确。其次，所涉及的锁相反馈刺激技术深度依赖对脑电相关神经动力学的机制，相关研究有利于我们对脑电信号中alpha的生成以及演化机制的深入理解。第三，本项目实现了alpha节律幅值频率的调节，相关技术有助于深入理解脑电节律alpha波成分与行为认知的关系。