Department of Physiology, University of Siena, Italy.
Neurosci Lett. 2010 Feb 5;470(1):13-8. doi: 10.1016/j.neulet.2009.12.044. Epub 2009 Dec 23.
Hypnotizability is a cognitive multidimensional trait that involves peculiar imagery characteristics. Subjects with high- (Highs) and low (Lows)-susceptibilities to hypnosis have shown different levels of skill at visual and somesthetic-guided imageries performed during upright stance. The aim of this experiment is to study the modulation of the EEG alpha and theta band amplitude during guided visual and somesthetic imageries in Highs and Lows, as these rhythms are responsive to the cognitive activities involved in mental imagery. Our results show that, at variance with standing subjects, subjects in both groups in a semi-reclined position report higher vividness and lower effort for visual than for somesthetic imagery. EEG patterns however are different between the two groups. Highs exhibit a more widespread alpha desynchronization and slightly different EEG patterns during visual and somesthetic imageries, while Lows show segregated alpha- and theta-desynchronization, without any difference between the tasks. Our results indicate that different, hypnotizability-related cognitive strategies, that are revealed by differences in EEG modulation, are responsible for the similar subjective experience associated with visual and somesthetic imageries in Highs and Lows. In addition, in both groups higher order mental representation of different sensory modalities might be subserved by a unique integrated neural network.
催眠易感性是一种认知多维特质，涉及特殊的意象特征。高（Highs）和低（Lows）催眠易感性的受试者在直立姿势下进行视觉和体感引导想象时表现出不同水平的技能。本实验的目的是研究在高（Highs）和低（Lows）催眠易感性受试者中，引导视觉和体感想象时 EEG 阿尔法和 theta 波段振幅的调制，因为这些节律对涉及心理意象的认知活动有反应。我们的结果表明，与站立受试者不同，两组受试者在半躺位置时报告视觉想象比体感想象的生动度更高，努力程度更低。然而，两组之间的脑电图模式不同。高（Highs）组在视觉和体感想象时表现出更广泛的阿尔法去同步化和略有不同的脑电图模式，而低（Lows）组表现出分离的阿尔法和 theta 去同步化，任务之间没有差异。我们的结果表明，不同的催眠易感性相关认知策略，通过 EEG 调制的差异来揭示，是导致高（Highs）和低（Lows）催眠易感性受试者在视觉和体感想象中产生相似主观体验的原因。此外，在两组中，不同感觉模态的更高阶心理表象可能由一个独特的整合神经网络来支持。
