The purpose of this study is to assess thalamocortical (TC) connectivity during tonic pressure pain, to evaluate alpha activity during tonic pressure pain and to determine pressure pain ratings by using Electroencephalography (EEG), Functional Magnetic Resonance Imaging (fMRI), Transcranial Alternating Current Stimulation (tACS), sham and Transcranial random noise stimulation (tRNS)

Inclusion Criteria:

• Meet the MRI / EEG screening criteria
• Fluent in English

Exclusion Criteria:

• Current or history of major medical, neurological, or psychiatric illness based on self-report
• History of cardiac, respiratory, or nervous system disease that, in the investigator's judgment, precludes participation in the study because of a heightened potential for adverse outcome (for example: asthma or claustrophobia)
• History of head trauma
• Pregnant or lactating
• Presence of any contraindications to MRI scanning (for example: cardiac pacemaker, metal implants, claustrophobia, pregnancy, cannot lie still in fMRI scanner)
• Conditions making study participation difficult (e.g., paralysis, psychoses, or other severe psychological problems as per the judgment of a study investigator during Session 1)
• Active substance abuse disorders (based on subject self-report)