Center for BrainHealth, School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA.
Center for BrainHealth, School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA.
Neuroimage. 2018 Oct 1;179:176-186. doi: 10.1016/j.neuroimage.2018.06.031. Epub 2018 Jun 9.
Studies have shown altered task-based brain functioning as a result of cannabis use. To date, however, whether similar alterations in baseline resting state and functional organization of neural activity are observable in cannabis users remains unknown. We characterized global resting state cortical activations and functional connectivity via electroencephalography (EEG) in cannabis users and related these activations to measures of cannabis use. Resting state EEG in the eyes closed condition was collected from age- and sex-matched cannabis users (N = 17; 6 females; mean age = 30.9 ± 7.4 years) and non-using controls (N = 21; 9 females; mean age = 33.1 ± 11.6 years). Power spectral density and spectral coherence were computed to determine differences in cortical activations and connectivity between the two groups in the delta (1-4Hz), theta (4-7 Hz), alpha (8-12 Hz), beta (13-30 Hz), and gamma (31-50 Hz) frequency bands. Cannabis users exhibited decreased delta and increased theta, beta, and gamma power compared to controls, suggesting increased cortical activation in resting state and a disinhibition of inhibitory functions that may interrupt cognitive processes. Cannabis users also exhibited increased interhemispheric and intrahemispheric coherence relative to controls, reduced mean network degree, and increased clustering coefficient in specific regions and frequencies. This increased cortical activity may indicate a loss of neural refinement and efficiency that may indicate a "noisy" brain. Lastly, measures related to cannabis use were correlated with spectral power and functional connectivity measures, indicating that specific electrophysiological signals are associated with cannabis use. These results suggest that there are differences in cortical activity and connectivity between cannabis users and non-using controls in the resting state that may be related to putative cognitive impairments and can inform effectiveness of intervention programs.
研究表明，大麻使用会改变基于任务的大脑功能。然而，迄今为止，大麻使用者是否存在静息状态下基线和神经活动功能组织的类似改变尚不清楚。我们通过脑电图（EEG）描述了大麻使用者的全局静息状态皮质激活和功能连接，并将这些激活与大麻使用的测量结果相关联。从年龄和性别匹配的大麻使用者（N=17；女性 6 名；平均年龄 30.9±7.4 岁）和非使用者对照（N=21；女性 9 名；平均年龄 33.1±11.6 岁）中采集闭眼状态下的静息状态 EEG。计算功率谱密度和频谱相干性，以确定两组在 delta（1-4Hz）、theta（4-7Hz）、alpha（8-12Hz）、beta（13-30Hz）和 gamma（31-50Hz）频段之间皮质激活和连接的差异。与对照组相比，大麻使用者的 delta 降低，theta、beta 和 gamma 功率增加，表明静息状态下皮质激活增加，抑制功能抑制中断，可能会干扰认知过程。与对照组相比，大麻使用者还表现出大脑两半球间和大脑半球内的相干性增加，特定区域和频率的平均网络度数降低，聚类系数增加。这种皮质活动的增加可能表明神经细化和效率的丧失，这可能表明大脑“嘈杂”。最后，与大麻使用相关的测量值与频谱功率和功能连接测量值相关，表明特定的电生理信号与大麻使用相关。这些结果表明，大麻使用者和非使用者对照在静息状态下的皮质活动和连接存在差异，这些差异可能与潜在的认知障碍有关，并为干预计划的有效性提供信息。
