Inclusion Criteria:  Aged 18 years old or older Healthy Volunteers Capable of understanding instructions Abstain from tobacco and caffeine 2 hours before data collection Abstain from short-acting analgesics 6 hours before data collection  Exclusion Criteria:  A painful condition or chronic pain Neurological disorders Shoulder pathology Skin diseases Capsaicin allergy Raynaud's syndrome Epilepsy Intracranial metallic foreign bodies, hearing aids and cochlear implants