Waking EEG Spectral Power and Coherence Differences Between High and Low Hypnotizable Subjects

Abstract

EEG spectral power and coherence were analyzed under waking baseline condition in 19 high (HH) and 12 low (LH) hypnotizable subjects. In HH subjects, the theta1 and theta2 spectral power was higher than in LH. The major new finding of this study is that coherence between distributed brain regions was sharply elevated in HH subjects within the theta and alpha frequency bands. In contrast, spectral power and coherence of beta2 and gamma1 bands were higher in LH subjects as compared to HH subjects. However, the long distance coherence between frontal and posterior areas within beta-gamma frequency ranges was higher in HH subjects. It might be supposed that HH subjects are engaged in imaginal mental activity whereas LH ones are mainly engaged in linguistic activity. The neurophysiological basis of the obtained EEG differences is discussed.

Neurophysiology of hypnosis

“…Highly hypnotizable subjects demonstrate a reduction of gamma EEG density, in contrast to subjects with low hypnotizability [9,21,33]. However, other studies found opposite results, i.e.…”

“…Beta activity was found to discriminate between high and low hypnotizable subjects [9]. Highly hypnotizable subjects seem to be characterized by a lower beta range as compared to low hypnotizable subjects [33].…”

“…Regarding other EEG rhythms, several studies have shown that level of theta activity (associated with inhibition of responses) increased as a function of hypnotizability [46]. It appears that highly hypnotizable subjects generated substantially more theta power than did low subjects, with a larger difference in frontal locations [3,33,54]. In addition, hypnosis (in low and high subjects) seems to increase mean theta power, suggesting an intensification of attentional processes [54].…”

“…topological and temporal dimensions of the signal) have been reported as the best features for classification of subjects in low, medium or high hypnotizable [3]. By studying coherence of the EEG signal, Kirenskaya et al [33] showed that baseline EEG differed in coherence between subjects with high and low hypnotizability. Indeed, highly hypnotizable subjects were characterized by higher distributed brain regions coherence within delta, theta, and alpha bands.…”

Eficacia de la hipnosis en la modificación de variables psicológicas y fisiológicas en deportistas

“…Por otro lado, dentro del numeroso conjunto de teorías que tratan de explicar el funcionamiento de la hipnosis (Kirenskaya, Novotosky & Zvonikov, 2011;Landolt & Milling, 2011;Raz, Uriel & Shany, 2011), para desarrollar el procedimiento "hipnótico" en esta investigación se tomó como referencia el "enfoque alternativo", donde los "fenómenos" hipnóticos se explican como un proceso motivacionalmente inducido que tienen lugar por la adecuada manipulación de características psicológicas y psicosociales (Jara & Martínez, 1999;Pérez, 1999). En este sentido, el procedimiento desarrollado basado en este enfoque, podría favorecer a priori en los participantes mejores puntuaciones en las variables de tipo psicológico evaluadas.…”