title: Hypnotizability-related EEG alpha and theta activities during visual and somesthetic imageries.
abstract: 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.
authors.affiliation: Department of Physiology, University of Siena, Italy.
authors.forename: Francesca I
authors.initials: FI
authors.lastname: Cavallaro
authors.forename: Immacolata
authors.initials: I
authors.lastname: Cacace
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Del Testa
authors.forename: Paolo
authors.initials: P
authors.lastname: Andre
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Carli
authors.forename: Vilfredo
authors.initials: V
authors.lastname: De Pascalis
authors.forename: Raffaele
authors.initials: R
authors.lastname: Rocchi
authors.forename: Enrica L
authors.initials: EL
authors.lastname: Santarcangelo
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D006990:Hypnosis; D007092:Imagination / Q000502:physiology*; D007407:Interviews as Topic; D008297:Male; D008606:Mental Processes / Q000502:physiology; D011581:Psychological Tests; D013826:Theta Rhythm; D055698:Touch Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult