Twenty-one CHR patients (13 male, 8 female) were ascertained from the Center of Prevention & Evaluation (COPE) at New York State Psychiatric Institute at Columbia University, a clinical research program that evaluates and treats adolescents and young adults (ages 12–30) who are considered at heightened clinical risk for psychosis on the basis of attenuated psychotic symptoms and/or genetic risk in the context of functional decline. Patients are followed for up to four years to determine transition to psychotic disorder, typically schizophrenia. Patients were compared in cross-section to 20 healthy volunteers (13 male, 7 female), who were ascertained from the same source population in the New York metropolitan area using flyers, brochures, and the internet. All participants received US$10/hr plus an extra US$10 travel compensation for each research appointment. Although the initial sample consisted of 24 patients and 21 controls, the data of 3 patients and 1 control had to be excluded due to technical issues during the olfactory EEG recordings. Demographic and clinical characteristics of the final sample are summarized in Table 1. Participants, who had no history of neurological
