SENSORY-MOTOR CORTEX ACTIVITY MODULATION BY HYPNOTIC SUSCEPTTBILITY AND HYPNOSIS DURING FINGER MOVEMENT

摘要

Studies on modulations of motor control induced by hypnosis or linked to hypnotic susceptibility have been focused, till now, on reflex activity. In fact, besides the observation of decrements in spontaneous blinking in awake hypnotizable subjects performing a visual task (Field et al. 1996), spinal reflexes have been mostly investigated. In particular, a complex supraspinal modulation oi the late component of the noxious reflex during hypnotic suggestion of analgesia (Danziger et al. 1998; Kiernan et al. 1995; Zachariae et al. 1998) and a less intense nystagmus after both rotatory and caloric stimulation during suggestions of decreased rotatory sensations (Aschan et al. 1962) have been described. In hypnotizable individuals (Highs), the decrease of the soleus monosynaptic (H) reflex amplitude (Hoffmann 1922), observed during a long-lasting simple relaxation and a neutral hypnosis (hypnosis without any specific suggestion except relaxation) can be attributed to a higher habituability of Highs with respect to non hypnotizable subjects (Lows) (Santarcangelo et al. 1989). A different relationship among H amplitude, previous reflexes amplitudes and interstimulus intervals has also been detected in Highs and Lows with a time series analysis of H reflexes elicited through random stimulation (Busse et al. 1993). In addition, in Highs, during hypnosis and long-lasting simple relaxation, the post-synaptic component of the cervical motoneiirones excitability, concerning the distal flexor muscles of upper limbs and evaluated through F waves (Eccles 1995) lowered only on the right side (Santarcangelo et al. 2003).