Shim Hwan, Gibbs Leah, Rush Karsyn, Ham Jusung, Kim Subong, Kim Sungyoung, Choi Inyong
Department of Electrical and Computer Engineering Technology, Rochester Institute of Technology, Rochester, NY 14623, USA.
Department of Communication Sciences and Disorders, University of Iowa, Iowa City, IA 52242, USA.
Appl Sci (Basel). 2023 Jul;13(14). doi: 10.3390/app13148499. Epub 2023 Jul 23.
Selective attention can be a useful tactic for speech-in-noise (SiN) interpretation as it strengthens cortical responses to attended sensory inputs while suppressing others. This cortical process is referred to as attentional modulation. Our earlier study showed that a neurofeedback training paradigm was effective for improving the attentional modulation of cortical auditory evoked responses. However, it was unclear how such neurofeedback training improved attentional modulation. This paper attempts to unveil what neural mechanisms underlie strengthened auditory selective attention during the neurofeedback training paradigm. Our EEG time-frequency analysis found that, when spatial auditory attention was focused, a fronto-parietal brain network was activated. Additionally, the neurofeedback training increased beta oscillation, which may imply top-down processing was used to anticipate the sound to be attended selectively with prior information. When the subjects were attending to the sound from the right, they exhibited more alpha oscillation in the right parietal cortex during the final session compared to the first, indicating improved spatial inhibitory processing to suppress sounds from the left. After the four-week training period, the temporal cortex exhibited improved attentional modulation of beta oscillation. This suggests strengthened neural activity to predict the target. Moreover, there was an improvement in the strength of attentional modulation on cortical evoked responses to sounds. The Placebo Group, who experienced similar attention training with the exception that feedback was based simply on behavioral accuracy, did not experience these training effects. These findings demonstrate how neurofeedback training effectively improves the neural mechanisms underlying auditory selective attention.
选择性注意对于噪声环境下言语（SiN）的解读而言可能是一种有用的策略，因为它能增强皮层对所关注的感觉输入的反应，同时抑制其他输入。这种皮层过程被称为注意力调制。我们早期的研究表明，一种神经反馈训练范式对于改善皮层听觉诱发反应的注意力调制是有效的。然而，尚不清楚这种神经反馈训练是如何改善注意力调制的。本文试图揭示在神经反馈训练范式期间，增强听觉选择性注意背后的神经机制是什么。我们的脑电图时频分析发现，当空间听觉注意力集中时，一个额顶叶脑网络被激活。此外，神经反馈训练增加了β振荡，这可能意味着自上而下的加工被用于利用先前信息预测即将被选择性关注的声音。当受试者关注来自右侧的声音时，与第一次相比，他们在最后一次实验中右侧顶叶皮层表现出更多的α振荡，这表明空间抑制加工得到改善，以抑制来自左侧的声音。在为期四周的训练期后，颞叶皮层对β振荡的注意力调制有所改善。这表明预测目标的神经活动增强。此外，对声音的皮层诱发反应的注意力调制强度也有所改善。安慰剂组接受了类似的注意力训练，只是反馈仅基于行为准确性，并未体验到这些训练效果。这些发现证明了神经反馈训练如何有效地改善听觉选择性注意背后的神经机制。
