Inclusion Criteria:  meet diagnostic criteria for schizophrenia, schizoaffective disorder, or psychotic bipolar disorder as verified by the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV TR) and consensus clinical diagnosis; had no changes to relevant anti-psychotic medications for a period of 1 month prior to participation; had a sufficient level of English to allow participation.  Exclusion Criteria:  pregnant or breastfeeding women; Intelligence quotient <60 any major medical or neurologic diagnosis of substance abuse positive urine drug screen history of moderate-to-severe visual impairment secondary to glaucoma, cataract or macular degeneration serious medical illness or instability requiring hospitalization within the next year relevant skin allergies; metallic or electronic implants (e.g. pacemakers, brain stimulators).