Does hypnotic assessment predict the functional equivalence between motor imagery and action?

Motor imagery is influenced by individual and contextual factors. We investigated whether the psychophysiological trait of hypnotisability modulates its subjective experience and cortical correlates similarly to what was previously shown for head postures mental images. EEG was acquired in 18 high (highs) and 15 low (lows) hypnotizable subjects (Stanford Hypnotic Susceptibility Scale, A). The experimental conditions were: baseline, a complex arm/hand movement, visual (1st person) and kinesthetic imagery of the movement. After each imagery condition, participants scored the vividness and easeness of their performance and their ability to mantain the requested modality of imagery. Subjective reports, chronometric visual/kinesthetic indices, absolute beta and fronto-central midline alpha powers were analyzed. Findings confirmed earlier reports of better kinestetic imagery ability in highs than in lows and better visual than kinesthetic imagery in lows, as well as smaller restructuring of the cortical activity in highs than in lows, during all tasks. Also, they show that hypnotisability accounts for most of the correlations between brain regions for both alpha and beta changes. Thus, imagined and actual movements were less demanding processes in highs at subjective and cortical levels. Finally, hypnotic assessment assists to plan personalized mental training for neuro-rehabilitation and sports and predict their efficacy.