This study is intended to investigate neurophysiological mechanisms of hypnosis using transcranial magnetic stimulation (TMS) and assessment of motor cortex excitability in healthy volunteers under hypnosis.

Inclusion Criteria: .

1. Healthy volunteers aged 20 to 45 years.
2. Hypnotisability above 14 as measured by the Tellegan absorption scale.

Exclusion Criteria:

1. Psychiatric diagnosis in axis I or axis II;
2. Documented history of head injury or seizure disorder;
3. Evidence of a disorder which could affect peripheral and central conduction such as multiple sclerosis, motor neuron disease, carpal tunnel syndrome, cervical spondylosis, diabetic neuropathy.
4. Any other contraindication to TMS as specified in the safety guidelines for rTMS (Wassermann, 1998) such as cardiac pacemakers or metallic deep brain electrodes.
5. Chronic pharmacological treatment.