Hypnotizability-related integration of perception and action.

Hypnotizability is a cognitive trait able to modulate many behavioural/physiological processes and associated with peculiar functional characteristics of the frontal executive system. This review summarizes experimental results on hypnotizability-related differences in sensorimotor integration at a reflex and an integrated level (postural control) and suggests possible interpretations based on morpho-functional considerations. In particular, hypnotizability-related differences in spinal motoneurones excitability are described, and the role of attention and imagery in maintaining a stable upright stance when sensory information is reduced or altered and when attention is absorbed in cognitive tasks is discussed as a function of hypnotic susceptibility. The projections from prefrontal cortex to spinal motoneurones and the balance between the activation of the right and left cortical hemisphere are considered responsible for the hypnotizability-related modulation of reflex responses, while the differences in postural control between subjects with high (highs) and low (lows) hypnotic susceptibility are considered a possible consequence of the activity of the locus coeruleus, which is also involved in attention, and of the cerebellum, which might be responsible for different internal models of postural control. We suggest a highly pervasive role of hypnotic susceptibility in human behaviour through the modulation of the integration of perception and action, which could be relevant for neurorehabilitative treatments and for the adaptation to special environments.