Hambrook Dillon A, Tata Matthew S
The University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada.
The University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada.
Brain Lang. 2019 Mar;190:1-9. doi: 10.1016/j.bandl.2018.12.005. Epub 2019 Jan 4.
Attention is crucial to speech comprehension in real-world, noisy environments. Selective phase-tracking between low-frequency brain dynamics and the envelope of target speech is a proposed mechanism to reject competing distractors. Studies have supported this theory in the case of a single distractor, but have not considered how tracking is systematically affected by varying distractor set sizes. We recorded electroencephalography (EEG) during selective listening to both natural and vocoded speech as distractor set-size varied from two to six voices. Increasing set-size reduced performance and attenuated EEG tracking of target speech. Further, we found that intrusions of distractor speech into perception were not accompanied by sustained tracking of the distractor stream. Our results support the theory that tracking of speech dynamics is a mechanism for selective attention, and that the mechanism of distraction is not simple stimulus-driven capture of sustained entrainment of auditory mechanisms by the acoustics of distracting speech.
在现实世界的嘈杂环境中，注意力对于言语理解至关重要。低频脑动力学与目标语音包络之间的选择性相位跟踪是一种被提出的用于排除竞争性干扰物的机制。研究在单一干扰物的情况下支持了这一理论，但尚未考虑跟踪如何受到不同干扰物集合大小的系统性影响。我们在选择性聆听自然语音和经声码转换的语音时记录脑电图（EEG），此时干扰物集合大小从两个声音变化到六个声音。集合大小的增加降低了表现，并减弱了对目标语音的EEG跟踪。此外，我们发现干扰语音侵入感知时，并未伴随着对干扰流的持续跟踪。我们的结果支持了这样一种理论，即语音动力学的跟踪是选择性注意力的一种机制，并且干扰机制并非简单的由干扰语音的声学特征驱动的对听觉机制持续夹带的刺激捕获。
