Inclusion Criteria:

• * Women of child bearing age cannot be pregnant or trying to become pregnant
• * Ability to tolerate small, enclosed spaces without anxiety
• * Ability and willingness to give informed consent to participate
• * No history of neurological disorder
• * Right handed
• * English speaking

Exclusion Criteria:

• * Are left-handed
• * Are younger than 18 or older than 50 years old
• * Women who are pregnant, suspect they are pregnant, or are attempting to become pregnant
• * Have metal anywhere in the head, excluding the mouth
• * Have a pacemaker, deep brain stimulator, vagus nerve stimulator or any other medically implanted device
• * Have cochlear hearing implants
• * Are taking GABAergic, NDMA-receptor antagonist, or other drug known to influence neural receptors
• * Have any of the below conditions that would put participants at increased risk of having a seizure: a personal or family history of seizure/epilepsy, taking prescription drugs that lower the threshold for seizures, recent history of excessive alcohol consumption, history of alcohol addiction/dependence, recent history of recreational drug use, history of drug addiction/dependence
• * Have been diagnosed with any of the following: a stroke, brain hemorrhage, brain tumor, encephalitis, multiple sclerosis, Parkinson's disease or Alzheimer's disease, depression in the past 6 months, attention deficit disorder, schizophrenia, manic depressive (bipolar) disorder, normal pressure hydrocephalus or increased intra-cranial pressure, diabetes requiring insulin treatment, any serious heart disorder or liver disease
• * Have had a migraine in the past month