title: Pitch and Duration Mismatch Negativity and Premorbid Intellect in the First Hospitalized Schizophrenia Spectrum.
abstract: Mismatch negativity (MMN) is a robustly abnormal brainwave in chronically ill schizophrenia that has generated interest as a disease presence biomarker. Reports of MMN reduction in first-episode schizophrenia have been equivocal, raising uncertainty about its reduction at first psychotic break. Here we tested 29 schizophrenia-spectrum participants under 1 year from their first hospitalization for psychosis and 40 age-, gender-, parental socioeconomic status-, and Wechsler Adult Intelligence Scales III Information-matched healthy controls on both pitch and duration MMN. Participants performed a visual checkerboard tracking task while standard (1kHz, 50ms, 80%), pitch-deviant (1.2kHz, 50ms, 10%) and duration-deviant (1kHz, 100ms, 10%) tones were presented over headphones (75 dB) and EEG was recorded. Independent component analysis was used to remove eye movements and visual stimulus processing activity. Groups did not differ in pitch MMN or duration MMN amplitudes. Smaller pitch and duration MMN amplitudes were associated with lower estimates of premorbid intellect in all participants and independently with greater positive symptoms in first hospitalized schizophrenia. Overall MMN reduction was not present in these relatively high functioning individuals at the first episode of schizophrenia, and therefore is not a good disease presence biomarker for this sample. Future research is warranted to determine the degree of MMN reduction at the first episode of psychosis across a greater range of cognitive impairment, the utility of MMN as an indicator of risk or diagnosis, and its role for understanding pathophysiological mechanisms in emerging psychosis.
authors.affiliation: Clinical Neurophysiology Research Laboratory, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA,  USA.
authors.forename: Dean F
authors.initials: DF
authors.lastname: Salisbury
authors.affiliation: Clinical Neurophysiology Research Laboratory, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA,  USA.|University of Texas Health Science Center at Houston, Houston, TX, USA.
authors.forename: Nicola R
authors.initials: NR
authors.lastname: Polizzotto
authors.affiliation: Department of Psychology, University of Massachusetts, Boston, MA,  USA.
authors.forename: Paul G
authors.initials: PG
authors.lastname: Nestor
authors.affiliation: Clinical Neurophysiology Research Laboratory, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA,  USA.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Haigh
authors.affiliation: Clinical Neurophysiology Research Laboratory, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA,  USA.
authors.forename: Justine
authors.initials: J
authors.lastname: Koehler
authors.affiliation: Department of Psychiatry, Harvard Medical School, VA Boston Healthcare System, Brockton Division, Brockton, MA,  USA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: McCarley
mesh_terms: D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D007360:Intelligence / Q000502:physiology*; D008297:Male; D010898:Pitch Perception / Q000502:physiology; D011618:Psychotic Disorders / Q000503:physiopathology*; D012559:Schizophrenia / Q000503:physiopathology*; D055815:Young Adult
keywords: IQ matching; biomarker; first episode; psychosis; sensory memory