Kucyi Aaron, Salomons Tim V, Davis Karen D
Division of Brain, Imaging and Behaviour-Systems Neuroscience, Krembil Research Institute, University Health Network, Toronto, ON, Canada.
Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
Pain. 2016 Sep;157(9):1895-1904. doi: 10.1097/j.pain.0000000000000592.
Repeated sensory exposures shape the brain's function and its responses to environmental stimuli. An important clinical and scientific question is how exposure to pain affects brain network activity and whether that activity is modifiable with training. We sought to determine whether repeated pain exposure would impact brain network activity and whether these effects can be reversed by cognitive behavioral therapy (CBT)-based training. Healthy subjects underwent 8 experimental sessions on separate days on which they received painful thermal stimuli. They were randomly assigned to groups receiving either CBT-based training (regulate group, n = 17) or a non-pain-focused treatment (control group, n = 13). Before and after these sessions, participants underwent functional magnetic resonance imaging (fMRI) during painful stimulation and at rest. The effect of repeated pain over time in the control group was a decrease in the neurotypical pain-evoked default mode network (DMN) deactivation. The regulate group did not show these DMN effects but rather had decreased deactivation of the right ventrolateral prefrontal cortex (R vlPFC) of the executive control network. In the regulate group, reduced pain-evoked DMN deactivation was associated with greater individual reduction in pain intensity and unpleasantness over time. Finally, the regulate group showed enhanced resting functional connectivity between areas of the DMN and executive control network over time, compared with the control group. Our study demonstrates that trainable cognitive states can alter the effect of repeated sensory exposure on the brain. The findings point to the potential utility of cognitive training to prevent changes in brain network connectivity that occur with repeated experience of pain.
反复的感觉刺激塑造了大脑的功能及其对环境刺激的反应。一个重要的临床和科学问题是,接触疼痛如何影响大脑网络活动,以及这种活动是否可以通过训练来改变。我们试图确定反复接触疼痛是否会影响大脑网络活动,以及这些影响是否可以通过基于认知行为疗法(CBT)的训练来逆转。健康受试者在不同的日子里接受了8次实验,期间他们接受了疼痛性热刺激。他们被随机分为接受基于CBT训练的组(调节组,n = 17)或非疼痛聚焦治疗组(对照组,n = 13)。在这些实验前后,参与者在疼痛刺激期间和休息时接受了功能磁共振成像(fMRI)。对照组中,随着时间的推移,反复疼痛的影响是神经典型的疼痛诱发默认模式网络(DMN)失活减少。调节组没有表现出这些DMN效应,而是执行控制网络的右侧腹外侧前额叶皮质(R vlPFC)失活减少。在调节组中,疼痛诱发的DMN失活减少与随着时间推移个体疼痛强度和不愉快程度的更大降低相关。最后,与对照组相比,调节组随着时间的推移在DMN和执行控制网络区域之间显示出增强的静息功能连接。我们的研究表明,可训练的认知状态可以改变反复感觉暴露对大脑的影响。这些发现指出了认知训练在预防因反复经历疼痛而发生的大脑网络连接变化方面的潜在效用。