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Introduction The aim of this exploratory study was to assess the EEG correlates of head positions (which have never been studied in humans) in participants with different psychophysiological characteristics, as encoded by their hypnotizability scores. This choice is motivated by earlier studies suggesting different processing of vestibular/neck proprioceptive information in subjects with high (highs) and low (lows) hypnotizability scores maintaining their head rotated toward one side ( RH ). Methods We analyzed EEG signals recorded in 20 highs and 19 lows in basal conditions (head forward) and during RH using spectral analysis, which captures changes localized to specific recording sites, and topological data analysis ( TDA ), which instead describes large‐scale differences in processing and representing sensorimotor information. Results Spectral analysis revealed significant differences related to head position for alpha 1, beta 2, beta 3, and gamma bands, but not to hypnotizability. TDA instead revealed global hypnotizability‐related differences in the strengths of the correlations among recording sites during RH . Significant changes were observed in lows on the left parieto‐occipital side and in highs in right frontoparietal region. Significant differences between the two groups were found in the occipital region, where changes were larger in lows than in highs . Conclusions This study reports finding of the EEG correlates of changes in the head posture for the first time, indicating that hypnotizability is related to the head posture representation/processing on large‐scale networks and that spectral and topological data analyses provide complementary results.

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The functional equivalence between mental images and perception or motion has been proposed on the basis of neuroimaging evidence of large spatially overlapping activations between real and imagined sensori-motor conditions. However, similar local activation patterns do not imply the same mesoscopic integration of brain regions active during imagery and perception or action. Here we present the first EEG evidence of topological equivalence between functional network organization at intermediate and global scales during tasks. We show that the degree of functional equivalence varies in the population and is associated with different magnitudes in the restructuring of the functional connectivity between imagery and real tasks. In particular, changes observed during imagery with respect to basal conditions account for the cognitive effort experienced during imagery, and subjects characterized by stronger functional equivalence exhibit smaller topological deviations in the imagination tasks performed after real tasks, thus showing learning effects. Altogether, our findings point to different sensori-cognitive information processing in the subjects showing different functional equivalence. We anticipate our results to be a starting point for a novel dynamical description of functional equivalence, which will be relevant for socio-cognitive theories of embodiment and cognitive formulations of how different selves emerge from neurophysiological assets.