The current protocol followed an odor detection task (Kayser et al., 2013) as part of a larger ERP study, with a substantial overlap of both samples (i.e., 20 CHR patients and 19 healthy participants provided valid data in both paradigms). After excluding the data of 1 patient and 1 control due to technical issues during the EEG recordings, the current sample included 22 CHR patients (15 male, 7 female) who were recruited from the Center of Prevention & Evaluation (COPE) at New York State Psychiatric Institute (NYSPI) at Columbia University. As a clinical research program, COPE evaluates and treats individuals aged between 12 and 30 years 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, and follows the individuals for up to four years to determine transition to psychotic disorder, typically schizophrenia. As a control group, 20 healthy volunteers (13 male, 7 female) were recruited from the same source population in the New York metropolitan area. All participants received US$10/h plus an extra US$10 travel compensation for each research appointment.
