Centre for Neuropsychopharmacology, Division of Brain Sciences, Department of Medicine, Imperial College London London, UK ; Computational, Cognitive and Clinical Neuroscience Laboratory, Division of Brain Sciences, Department of Medicine, Imperial College London London, UK.
Computational, Cognitive and Clinical Neuroscience Laboratory, Division of Brain Sciences, Department of Medicine, Imperial College London London, UK.
Front Hum Neurosci. 2014 May 27;8:204. doi: 10.3389/fnhum.2014.00204. eCollection 2014.
Perturbing a system and observing the consequences is a classic scientific strategy for understanding a phenomenon. Psychedelic drugs perturb consciousness in a marked and novel way and thus are powerful tools for studying its mechanisms. In the present analysis, we measured changes in resting-state functional connectivity (RSFC) between a standard template of different independent components analysis (ICA)-derived resting state networks (RSNs) under the influence of two different psychoactive drugs, the stimulant/psychedelic hybrid, MDMA, and the classic psychedelic, psilocybin. Both were given in placebo-controlled designs and produced marked subjective effects, although reports of more profound changes in consciousness were given after psilocybin. Between-network RSFC was generally increased under psilocybin, implying that networks become less differentiated from each other in the psychedelic state. Decreased RSFC between visual and sensorimotor RSNs was also observed. MDMA had a notably less marked effect on between-network RSFC, implying that the extensive changes observed under psilocybin may be exclusive to classic psychedelic drugs and related to their especially profound effects on consciousness. The novel analytical approach applied here may be applied to other altered states of consciousness to improve our characterization of different conscious states and ultimately advance our understanding of the brain mechanisms underlying them.
扰乱系统并观察其后果是理解现象的经典科学策略。迷幻药物以显著而新颖的方式扰乱意识，因此是研究其机制的有力工具。在本分析中，我们在两种不同的精神活性药物（兴奋剂/迷幻剂混合物 MDMA 和经典迷幻剂裸盖菇素）的影响下，测量了基于不同独立成分分析 (ICA) 得出的静息状态网络 (RSN) 的标准模板之间的静息状态功能连接 (RSFC) 的变化。这两种药物都采用安慰剂对照设计，并产生了明显的主观效果，尽管报告称裸盖菇素引起的意识变化更为深刻。在裸盖菇素作用下，网络间的 RSFC 通常增加，这意味着在迷幻状态下，网络之间的差异变小。还观察到视觉和感觉运动 RSN 之间的 RSFC 减少。MDMA 对网络间 RSFC 的影响明显较小，这表明裸盖菇素下观察到的广泛变化可能是经典迷幻药物所特有的，并且与它们对意识的深远影响有关。这里应用的新颖分析方法可以应用于其他意识改变状态，以改善我们对不同意识状态的描述，并最终推进我们对大脑机制的理解。
