Egner Tobias, Jamieson Graham, Gruzelier John
Functional MRI Research Center, Columbia University, Neurological Institute Box 108, 710 West 168th Street, New York, NY 10032, USA.
Neuroimage. 2005 Oct 1;27(4):969-78. doi: 10.1016/j.neuroimage.2005.05.002.
Hypnosis can profoundly alter sensory awareness and cognitive processing. While the cognitive and behavioral phenomena associated with hypnosis have long been thought to relate to attentional processes, the neural mechanisms underlying susceptibility to hypnotic induction and the hypnotic condition are poorly understood. Here, we tested the proposal that highly hypnotizable individuals are particularly adept at focusing attention at baseline, but that their attentional control is compromised following hypnosis due to a decoupling between conflict monitoring and cognitive control processes of the frontal lobe. Employing event-related fMRI and EEG coherence measures, we compared conflict-related neural activity in the anterior cingulate cortex (ACC) and control-related activity in the lateral frontal cortex (LFC) during Stroop task performance between participants of low and high hypnotic susceptibility, at baseline and after hypnotic induction. The fMRI data revealed that conflict-related ACC activity interacted with hypnosis and hypnotic susceptibility, in that highly susceptible participants displayed increased conflict-related neural activity in the hypnosis condition compared to baseline, as well as with respect to subjects with low susceptibility. Cognitive-control-related LFC activity, on the other hand, did not differ between groups and conditions. These data were complemented by a decrease in functional connectivity (EEG gamma band coherence) between frontal midline and left lateral scalp sites in highly susceptible subjects after hypnosis. These results suggest that individual differences in hypnotic susceptibility are linked with the efficiency of the frontal attention system, and that the hypnotized condition is characterized by a functional dissociation of conflict monitoring and cognitive control processes.
催眠能深刻改变感觉意识和认知加工。虽然长期以来人们一直认为与催眠相关的认知和行为现象与注意过程有关，但对催眠诱导易感性和催眠状态背后的神经机制却知之甚少。在此，我们检验了这样一种观点：高度易被催眠的个体在基线状态下特别擅长集中注意力，但由于额叶的冲突监测和认知控制过程之间的解耦，他们在催眠后注意力控制会受到损害。我们采用事件相关功能磁共振成像（fMRI）和脑电图（EEG）相干性测量方法，比较了低催眠易感性和高催眠易感性参与者在基线状态和催眠诱导后进行Stroop任务时，前扣带回皮质（ACC）中与冲突相关的神经活动以及外侧额叶皮质（LFC）中与控制相关的活动。功能磁共振成像数据显示，与冲突相关的前扣带回皮质活动与催眠及催眠易感性相互作用，即与基线状态相比，以及与低易感性受试者相比，高易感性参与者在催眠状态下表现出与冲突相关的神经活动增加。另一方面，与认知控制相关的外侧额叶皮质活动在不同组和不同条件之间没有差异。高易感性受试者在催眠后，额中线和左侧头皮部位之间的功能连接（脑电图γ波段相干性）降低补充了这些数据。这些结果表明，催眠易感性的个体差异与额叶注意系统的效率有关，并且催眠状态的特征是冲突监测和认知控制过程的功能分离。
