Department of Psychiatry, Psychotherapy and Psychosomatics, Faculty of Medicine, RWTH Aachen, Aachen, Germany.
Jara-Brain, Aachen, Germany.
Hum Brain Mapp. 2024 Dec 1;45(17):e70077. doi: 10.1002/hbm.70077.
One of the fundamental questions in real-time functional magnetic resonance imaging neurofeedback (rt-fMRI NF) investigations is the definition of a suitable neural target for training. Previously, we applied a meta-analytical approach to define a network-level target for connectivity-based rt-fMRI NF in substance use disorders. The analysis yielded consistent connectivity alterations between the insula and anterior cingulate cortex (ACC) as well as the dorsal striatum and the ACC. In the current investigation, we addressed the feasibility of regulating this network and its functional relevance using connectivity-based neurofeedback. In a double-blind, sham-controlled design, 60 nicotine users were randomly assigned to the experimental or sham control group for one NF training session. The preregistered primary outcome was defined as improved inhibitory control performance after regulation of the target network compared to sham control. Secondary outcomes were (1) neurofeedback-specific changes in functional connectivity of the target network; (2) changes in smoking behavior and impulsivity measures; and (3) changes in resting-state connectivity profiles. Our results indicated no differences in behavioral measures after receiving feedback from the target network compared to the sham feedback. Target network connectivity was increased during regulation blocks compared to rest blocks, however, the experimental and sham groups could regulate to a similar degree. Accordingly, the observed activation patterns may be related to the mental strategies used during regulation attempts irrespective of the group assignment. We discuss several crucial factors regarding the efficacy of a single-session connectivity-based neurofeedback for the target network. This includes high fluctuation in the connectivity values of the target network that may impact controllability of the signal. To our knowledge, this investigation is the first randomized, double-blind controlled real-time fMRI study in nicotine users. This raises the question of whether previously observed effects in nicotine users are specific to the neurofeedback signal or reflect more general self-regulation attempts.
实时功能磁共振成像神经反馈 (rt-fMRI NF) 研究中的一个基本问题是为训练定义合适的神经靶点。此前，我们应用元分析方法定义了基于连接的 rt-fMRI NF 在物质使用障碍中的网络水平靶点。该分析得出了岛叶和前扣带皮层 (ACC) 之间以及背侧纹状体和 ACC 之间一致的连接改变。在当前的研究中，我们使用基于连接的神经反馈来解决调节该网络及其功能相关性的可行性问题。在一项双盲、假对照设计中，60 名尼古丁使用者被随机分配到实验组或假对照组进行一次 NF 训练。预先注册的主要结果定义为与假对照相比，调节目标网络后抑制控制表现的改善。次要结果是：(1) 目标网络的功能连接的神经反馈特异性变化；(2) 吸烟行为和冲动性测量的变化；和 (3) 静息状态连接模式的变化。我们的结果表明，与假反馈相比，从目标网络接收到反馈后，行为测量没有差异。与休息块相比，在调节块期间目标网络的连接性增加，但实验组和假组可以以相似的程度进行调节。因此，观察到的激活模式可能与调节尝试期间使用的心理策略有关，而与组分配无关。我们讨论了关于单次基于连接的神经反馈对目标网络的功效的几个关键因素。这包括目标网络连接值的高波动，这可能会影响信号的可控性。据我们所知，这是首次在尼古丁使用者中进行的随机、双盲对照实时 fMRI 研究。这提出了一个问题，即在尼古丁使用者中观察到的先前效果是否特定于神经反馈信号，还是反映了更普遍的自我调节尝试。
