Intelligent Systems Research Centre, Ulster University, Derry, UK.
Institute for Research in Social Sciences, Ulster University, Jordanstown, UK.
Neurosci Biobehav Rev. 2022 Sep;140:104783. doi: 10.1016/j.neubiorev.2022.104783. Epub 2022 Jul 27.
Decoding speech and speech-related processes directly from the human brain has intensified in studies over recent years as such a decoder has the potential to positively impact people with limited communication capacity due to disease or injury. Additionally, it can present entirely new forms of human-computer interaction and human-machine communication in general and facilitate better neuroscientific understanding of speech processes. Here, we synthesize the literature on neural speech decoding pertaining to how speech decoding experiments have been conducted, coalescing around a necessity for thoughtful experimental design aimed at specific research goals, and robust procedures for evaluating speech decoding paradigms. We examine the use of different modalities for presenting stimuli to participants, methods for construction of paradigms including timings and speech rhythms, and possible linguistic considerations. In addition, novel methods for eliciting naturalistic speech and validating imagined speech task performance in experimental settings are presented based on recent research. We also describe the multitude of terms used to instruct participants on how to produce imagined speech during experiments and propose methods for investigating the effect of these terms on imagined speech decoding. We demonstrate that the range of experimental procedures used in neural speech decoding studies can have unintended consequences which can impact upon the efficacy of the knowledge obtained. The review delineates the strengths and weaknesses of present approaches and poses methodological advances which we anticipate will enhance experimental design, and progress toward the optimal design of movement independent direct speech brain-computer interfaces.
近年来，直接从人类大脑中解码言语和与言语相关的过程在研究中得到了加强，因为这样的解码器有可能对因疾病或受伤而沟通能力有限的人产生积极影响。此外，它可以为一般的人机交互和人机通信带来全新的形式，并促进对言语过程的更好的神经科学理解。在这里，我们综合了有关神经言语解码的文献，重点介绍了如何进行言语解码实验，围绕着针对特定研究目标的深思熟虑的实验设计和用于评估言语解码范式的稳健程序的必要性。我们研究了使用不同的模态向参与者呈现刺激的方法、包括时间安排和言语节奏的范式构建方法，以及可能的语言考虑因素。此外，根据最近的研究，提出了在实验环境中引出自然语言和验证想象中的言语任务表现的新方法。我们还描述了在实验期间指导参与者如何产生想象中的言语的多种术语，并提出了研究这些术语对想象中的言语解码的影响的方法。我们证明，神经言语解码研究中使用的实验程序范围可能会产生意外的后果，从而影响所获得知识的有效性。该综述阐述了当前方法的优缺点，并提出了我们预期将增强实验设计和朝着最优的运动独立直接言语脑机接口设计前进的方法上的进展。
