Pregnancy

Neurological conditions/illness (including epilepsy/convulsion/seizure)

Vascular, traumatic, tumoral, infectious, or metabolic lesion of the brain

Previous or current implants in their body that may be triggered or heated by an electrical current (e.g., cardiac pacemaker, intracranial shunts, artificial cochlea, medication infusion device)

Any metal implanted in their head (e.g., surgical clips, staples, shrapnel)

Frequent or intense headaches

Ringing in the ears or hearing problems

Previous brain trauma or neurosurgical intervention to the brain or spinal cord

Serious medical complications (e.g., advanced pulmonary, cardiac, liver or kidney disease)

Currently taking neuropsychotropic drugs (e.g., antiepileptics, neuroleptics, benzodiazepines, antidepressants) or drugs with an effect on neuroplasticity (dopamine, fluoxetine or D-amphetamine, sodium or calcium channel blockers, NMDA receptor antagonists)