Sustained attentional and disattentional abilities and arousability: Factor analysis and relationships to hypnotic susceptibility

The neurophysiologically separate dimensions of deeply focused, sustained attention and arousability are shown to be differentially related to hypnotic susceptibility. University undergraduates, 98 men and 112 women, were administered the Harvard Group Scale of Hypnotic Susceptibility; the Group Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C); and questionnaires that assessed attentional abilities (Differential Attentional Processes Inventory (DAPI), Tellegen Absorption Scale (TAS)), Extraversion (Eysenck Personality Questionnaire), strength of the nervous system (Strelau Temperament Scale (STS)), augmenting-reducing (Vando Reducer-Augmenter Scale (RAS)), and emotionality (Affect Intensity Measure (AIM)). Women were significantly higher on TAS, DAPI dual attention physical-cognitive scale, and AIM; men were significantly higher on TAS and STI Strength of Excitation Scale. Separate factor analyses for men and women separately yielded fairly similar four-factor solutions. The first major factor, defined by DAPI Moderately Focused Attention and Dual Attention scales, represented moderately sustained attention in a complex environment with limited interference from competing stimuli. The extremely involved and focused attention factor, defined by the TAS and DAPI Extremely Focused Attention Scale, had hypnotic susceptibility loaded more strongly for men than women. The arousability factor was defined by EPQ Extraversion, STI Mobility of Nervous System (MNS) scale, and RAS. The neo-Pavlovian nervous system processes factor was defined by the STI Strength of Excitation and Strength of Inhibition scales; the STI MNS scale also loaded on this factor for men. Only for women were introverts more hypnotizable than extraverts. Results support H. J. Crawford and J. H. Gruzelier's (1992) in E. Fromm and M. Nash (Eds.) Contemporary Perspectives in Hypnosis Research (pp. 227–266) New York: Guildford Press) neurophysiological model of hypnosis that proposes that highly hypnotizable persons have a more efficient fronto-limbic sustained attentional and disattentional system.