title: Exploratory eye movement dysfunction as a discriminator for schizophrenia : a large sample study using a newly developed digital computerized system.
abstract: In our previous studies, we identified that exploratory eye movement (EEM) dysfunction appears to be specific to schizophrenia. The availability of a biological marker specific to schizophrenia would be useful for clinical diagnosis of schizophrenia. Consequently, we performed the discriminant analysis between schizophrenics and non-schizophrenics on a large sample using the EEM test data and examined an application of the EEM for clinical diagnosis of schizophrenia. EEM performances were recorded in 251 schizophrenics and 389 non-schizophrenics (111 patients with mood disorders, 28 patients with neurotic disorders and 250 normal controls). The patients were recruited from eight university hospitals and three affiliated hospitals. For this study with a large sample, we developed a new digital computerized version of the EEM test, which automatically handled large amounts of data. We measured four parameters: number of eye fixations (NEF), total eye scanning length (TESL), mean eye scanning length (MESL) and responsive search score (RSS). These parameters of schizophrenics differed significantly from those of the other three groups. The stepwise regression analysis selected the TESL and the RSS as the valid parameters for discriminating between schizophrenics and non-schizophrenics. In the discriminant analysis using the RSS and TESL as prediction parameters, 184 of the 251 clinically diagnosed schizophrenics were discriminated as having schizophrenia (sensitivity 73.3%); and 308 of the 389 clinically diagnosed non-schizophrenic subjects were discriminated as non-schizophrenics (specificity 79.2%). Based on our findings we believe that the EEM measures may be useful for the clinical diagnosis of schizophrenia.
authors.affiliation: Dept. of Neuropsychiatry, Nihon University School of Medicine, 30-1 Oyaguchi-Kamicho, Itabashi-ku, Tokyo 173-8610, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Suzuki
authors.forename: Sakae
authors.initials: S
authors.lastname: Takahashi
authors.forename: Eisuke
authors.initials: E
authors.lastname: Matsushima
authors.forename: Masahiko
authors.initials: M
authors.lastname: Tsunoda
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kurachi
authors.forename: Takashi
authors.initials: T
authors.lastname: Okada
authors.forename: Takuji
authors.initials: T
authors.lastname: Hayashi
authors.forename: Yohei
authors.initials: Y
authors.lastname: Ishii
authors.forename: Kiichiro
authors.initials: K
authors.lastname: Morita
authors.forename: Hisao
authors.initials: H
authors.lastname: Maeda
authors.forename: Seiji
authors.initials: S
authors.lastname: Katayama
authors.forename: Ryuzou
authors.initials: R
authors.lastname: Kawahara
authors.forename: Tatsui
authors.initials: T
authors.lastname: Otsuka
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hirayasu
authors.forename: Mizuho
authors.initials: M
authors.lastname: Sekine
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Okubo
authors.forename: Mai
authors.initials: M
authors.lastname: Motoshita
authors.forename: Katsuya
authors.initials: K
authors.lastname: Ohta
authors.forename: Makoto
authors.initials: M
authors.lastname: Uchiyama
authors.forename: Takuya
authors.initials: T
authors.lastname: Kojima
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005106:Exploratory Behavior; D053483:Eye Movement Measurements / Q000295:instrumentation; D005133:Eye Movements; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D009497:Neurotic Disorders / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance; D012044:Regression Analysis; D012559:Schizophrenia / Q000175:diagnosis* / Q000503:physiopathology*; D055815:Young Adult