Objectives

According to some studies, a putatively calming effect of EEG neurofeedback training could be useful as a therapeutic tool in psychiatric practice. With the aim of elucidating this possibility, we tested the efficacy of a single session of ↑sensorimotor (SMR)/↓theta neurofeedback training for mood improvement in 32 healthy men, taking into account trainability, independence and interpretability of the results.

Methods

A pre-post design, with the following dependent variables, was applied: (i) psychometric measures of mood with regards to anxiety, depression, and anger (Profile of Mood State, POMS, and State Trait Anxiety Inventory, STAI); (ii) biological measures (salivary levels of cortisol); (iii) neurophysiological measures (EEG frequency band power analysis). In accordance with general recommendations for research in neurofeedback, a control group receiving sham neurofeedback was included.

Results

Anxiety levels decreased after the real neurofeedback and increased after the sham neurofeedback (P < 0.01, size effect 0.9 for comparison between groups). Cortisol decreased after the experiment in both groups, though with significantly more pronounced effects in the desired direction after the real neurofeedback (P < 0.04; size effect 0.7). The group receiving real neurofeedback significantly enhanced their SMR band (P < 0.004; size effect 0.88), without changes in the theta band. The group receiving sham neurofeedback did not show any EEG changes.

Conclusions

The improvement observed in anxiety was greater in the experimental group than in the sham group, confirmed by both subjective (psychometric) measures and objective (biological) measures. This was demonstrated to be associated with the real neurofeedback, though a nonspecific (placebo) effect likely also contributed.

中文翻译：

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单次SMR神经反馈训练对焦虑和皮质醇水平的影响。

目标

根据一些研究，EEG神经反馈训练的预期镇静作用可能会在精神病学实践中用作治疗工具。为了阐明这种可能性，我们在考虑可训练性，独立性和结果可解释性的基础上，测试了一次单次↑感觉运动（SMR）/↓theta神经反馈训练对改善32名健康男性的情绪的效果。

方法

采用具有以下因变量的事前设计：（i）关于焦虑，抑郁和愤怒的情绪心理测量（情绪状态，POMS和状态特质焦虑量表，STAI）；（ii）生物学措施（皮质醇的唾液水平）；（iii）神经生理学措施（EEG频带功率分析）。根据有关神经反馈研究的一般建议，包括接受假神经反馈的对照组。

结果

真正的神经反馈后焦虑水平降低，而假神经反馈后焦虑水平升高（P  <0.01，组间比较的大小效应为0.9）。两组实验后皮质醇均降低，但在真正的神经反馈后，在所需方向上有明显更明显的作用（P  <0.04；大小效应为0.7）。接受真实神经反馈的组显着增强了他们的SMR谱带（P  <0.004；大小效应0.88），而theta谱带没有变化。接受假神经反馈的组未显示任何脑电图变化。

结论

实验组观察到的焦虑改善比假手术组更大，这已通过主观（心理测量）和客观（生物学）测量得到证实。事实证明，这与真正的神经反馈有关，尽管非特异性（安慰剂）作用也可能起作用。