Department of Psychology, Northern Michigan University, Marquette, MI, USA.
Department of Psychology, Northern Michigan University, Marquette, MI, USA.
Med Hypotheses. 2017 Nov;109:6-16. doi: 10.1016/j.mehy.2017.09.002. Epub 2017 Sep 6.
Increased attentional bias to threat has been identified as a causal mechanism in the development of anxiety. As such, attention bias modification (ABM) was conceived as a treatment option where anxiety is alleviated through a computerized cognitive training regimen that reduces an individual's attentional bias to threat. Although ABM appears to be a promising treatment option for anxiety, the mechanism of action by which the treatment is effective is unknown. We hypothesize that effective ABM treatment is associated with neuroplasticity-related structural changes in an extended amygdala - prefrontal cortex network that can be detected with standard T-weighted magnetic resonance imaging (MRI). Literature regarding [1] effects of brain damage on attention bias, [2] functional neuroimaging of attention bias, [3] structural neuroimaging of attention bias, and [4] functional neuroimaging of ABM training all support the role of this network as the underlying mechanism of attention bias behavior and neuroplasticity-related changes in attentional bias. Additionally, we provide proof of principle pilot data that ABM training reduces MRI measures of gray matter volume in the basal forebrain/extended amygdala and medial prefrontal cortex. Greater reduction in gray matter volume corresponds to greater reduction in attentional bias. In addition, level of pre-training bias appears to be a strong indicator of treatment outcome. In short, we provide converging evidence for the hypothesis that the mechanism underlying effective ABM training is reduced gray matter volume in an extended amygdala network. MRI-based measures of neuroplasticity in this network could be an important target outcome for the treatment of anxiety with ABM.
注意力对威胁的偏向增加已被确定为焦虑发展的一种因果机制。因此，注意偏向修正（ABM）被设想为一种治疗选择，通过计算机认知训练方案减轻焦虑，该方案可减少个体对威胁的注意力偏向。尽管 ABM 似乎是一种有前途的焦虑治疗选择，但尚不清楚该治疗有效的作用机制。我们假设有效的 ABM 治疗与扩展杏仁核 - 前额叶皮层网络的神经可塑性相关的结构变化有关，可以通过标准 T 加权磁共振成像（MRI）检测到。关于[1]大脑损伤对注意力偏向的影响，[2]注意力偏向的功能神经影像学，[3]注意力偏向的结构神经影像学以及[4]ABM 训练的功能神经影像学的文献都支持该网络作为注意力偏向行为和注意力偏向的神经可塑性相关变化的潜在机制的作用。此外，我们提供了原理性的初步数据，证明 ABM 训练可减少基底前脑/扩展杏仁核和内侧前额叶皮层的 MRI 测量的灰质体积。灰质体积的减少与注意力偏向的减少成正比。此外，训练前的偏向程度似乎是治疗结果的一个重要指标。简而言之，我们为以下假设提供了确凿的证据：有效的 ABM 训练的机制是扩展的杏仁核网络中的灰质体积减少。该网络中神经可塑性的基于 MRI 的测量可能是 ABM 治疗焦虑的重要目标结果。
