Department of Biomedical, Industrial & Human Factors Engineering, Wright State University, Dayton, OH, USA.
Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indiana University, IN, USA.
Neuroimage. 2019 Jul 15;195:475-489. doi: 10.1016/j.neuroimage.2019.03.078. Epub 2019 Apr 5.
In this work, we investigated the use of real-time functional magnetic resonance imaging (fMRI) with neurofeedback training (NFT) to teach volitional down-regulation of the auditory cortex (AC) using directed attention strategies as there is a growing interest in the application of fMRI-NFT to treat neurologic disorders. Healthy participants were separated into two groups: the experimental group received real feedback regarding activity in the AC; the control group was supplied sham feedback yoked from a random participant in the experimental group and matched for fMRI-NFT experience. Each participant underwent five fMRI-NFT sessions. Each session contained 2 neurofeedback runs where participants completed alternating blocks of "rest" and "lower" conditions while viewing a continuously-updated bar representing AC activation and listening to continuous noise. Average AC deactivation was extracted from each closed-loop neuromodulation run and used to quantify the control over AC (AC control), which was found to significantly increase across training in the experimental group. Additionally, behavioral testing was completed outside of the MRI on sessions 1 and 5 consisting of a subjective questionnaire to assess attentional control and two quantitative tests of attention. No significant changes in behavior were observed; however, there was a significant correlation between changes in AC control and attentional control. Also, in a neural assessment before and after fMRI-NFT, AC activity in response to continuous noise stimulation was found to significantly decrease across training while changes in AC resting perfusion were found to be significantly greater in the experimental group. These results may be useful in formulating effective therapies outside of the MRI, specifically for chronic tinnitus which is often characterized by hyperactivity of the primary auditory cortex and altered attentional processes. Furthermore, the modulation of attention may be useful in developing therapies for other disorders such as chronic pain.
在这项工作中，我们研究了使用实时功能磁共振成像 (fMRI) 与神经反馈训练 (NFT)，通过定向注意力策略来教授听觉皮层 (AC) 的自主调节，因为人们对将 fMRI-NFT 应用于治疗神经系统疾病越来越感兴趣。健康参与者被分为两组：实验组接受关于 AC 活动的真实反馈；对照组提供与实验组中随机参与者相匹配的假反馈，并与 fMRI-NFT 经验相匹配。每位参与者都接受了五次 fMRI-NFT 训练。每次训练包含 2 次神经反馈运行，参与者在观看代表 AC 激活的连续更新条并聆听连续噪声时，完成“休息”和“降低”状态的交替块。从每个闭环神经调节运行中提取平均 AC 去激活值，用于量化对 AC 的控制 (AC 控制)，实验组在训练过程中发现该控制显著增加。此外，在 MRI 之外的第 1 次和第 5 次训练中完成了行为测试，包括评估注意力控制的主观问卷和两项注意力定量测试。没有观察到行为的显著变化；然而，AC 控制的变化与注意力控制之间存在显著相关性。此外，在 fMRI-NFT 前后的神经评估中，发现 AC 对连续噪声刺激的反应活动在训练过程中显著降低，而实验组的 AC 静息灌注变化显著增加。这些结果可能有助于制定 MRI 之外的有效治疗方法，特别是对于慢性耳鸣，其特征通常是初级听觉皮层的过度活跃和注意力过程的改变。此外，注意力的调节可能有助于开发治疗其他疾病的方法，如慢性疼痛。
