Changes in electromyographically recorded human monosynaptic reflex in relation to hypnotic susceptibility and...

Area of Science:

• Neuroscience
• Psychophysiology

Background:

• Motoneuron excitability is crucial for motor control.
• Hypnotic susceptibility varies among individuals.
• Understanding hypnosis's physiological effects requires objective measures.

Purpose of the Study:

• To investigate the impact of hypnotic susceptibility and hypnosis on motoneuron excitability.
• To differentiate the effects of hypnotic induction from inherent personality traits.

Main Methods:

• Selected human subjects based on hypnotic susceptibility.
• Measured Hoffmann (H) reflex amplitude in the soleus muscle.
• Compared three groups: highly susceptible subjects under hypnosis, highly susceptible subjects under control, and non-susceptible subjects under control.

Main Results:

• A significant decrease in H reflex amplitude was observed in highly susceptible subjects during hypnosis (Group I) and in highly susceptible subjects under control conditions (Group II).
• No significant change in H reflex amplitude was found in non-susceptible subjects (Group III).
• The observed decrements in H reflex amplitude did not significantly differ between Group I and Group II.

Conclusions:

• Hypnotic susceptibility, rather than hypnotic induction alone, is associated with reduced motoneuron excitability.
• Personality traits inherent to highly susceptible individuals may influence physiological responses during hypnosis.
• Further research is needed to elucidate the precise mechanisms linking hypnotic susceptibility to neurophysiological changes.