Background
We have investigated which eye-movement tests alone and combined can best discriminate
schizophrenia cases from control subjects and their predictive validity.
Methods
A training set of 88 schizophrenia cases and 88 controls had a range of eye movements
recorded; the predictive validity of the tests was then examined on eye-movement data
from 34 9-month retest cases and controls, and from 36 novel schizophrenia cases and
52 control subjects. Eye movements were recorded during smooth pursuit, fixation stability,
and free-viewing tasks. Group differences on performance measures were examined by
univariate and multivariate analyses. Model fitting was used to compare regression,
boosted tree, and probabilistic neural network approaches.
Results
As a group, schizophrenia cases differed from control subjects on almost all eye-movement
tests, including horizontal and Lissajous pursuit, visual scanpath, and fixation stability;
fixation dispersal during free viewing was the best single discriminator. Effects
were stable over time, and independent of sex, medication, or cigarette smoking. A
boosted tree model achieved perfect separation of the 88 training cases from 88 control
subjects; its predictive validity on retest assessments and novel cases and control
subjects was 87.8%. However, when we examined the whole data set of 298 assessments,
a cross-validated probabilistic neural network model was superior and could discriminate
all cases from controls with near perfect accuracy at 98.3%.
Conclusions
Simple viewing patterns can detect eye-movement abnormalities that can discriminate
schizophrenia cases from control subjects with exceptional accuracy.
Key Words
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to Biological PsychiatryAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- An experimental study of the ocular reactions of the insane from photographic records.Brain. 1908; 31: 451-489
- Eye-tracking dysfunctions in schizophrenic patients and their relatives.Arch Gen Psychiatry. 1974; 31: 143-151
- Eye tracking dysfunction unrelated to clinical state and treatment with haloperidol.Biol Psychiatry. 1983; 18: 813-819
- Pursuit eye movement dysfunctions in schizophrenia.Arch Gen Psychiatry. 1984; 41: 136-139
- Auditory P300 and eye tracking dysfunction in schizophrenic pedigrees.Arch Gen Psychiatry. 1991; 48: 899-909
- Smooth-pursuit eye movement dysfunction and liability for schizophrenia: Implications for genetic modeling.J Abnorm Psychol. 1992; 101: 117-129
- Smooth pursuit ocular motor dysfunction in schizophrenia: Evidence for a major gene.Am J Psychiatry. 1992; 149: 1362-1368
- Smooth-pursuit eye tracking in first-episode psychotic patients and their relatives.J Abnorm Psychol. 1992; 101: 104-116
- Association of abnormal smooth pursuit eye movements with the deficit syndrome in schizophrenic patients.Am J Psychiatry. 1996; 153: 1158-1165
- A quantitative analysis of smooth pursuit eye tracking in monozygotic twins discordant for schizophrenia.Arch Gen Psychiatry. 1997; 54: 417-426
- Poor performance in smooth pursuit and antisaccadic eye-movement tasks in healthy siblings of patients with schizophrenia.Psychiatry Res. 2001; 101: 209-219
- Eye movement and neuropsychological studies in first-degree relatives of schizophrenic patients.Schizophr Res. 2002; 54: 105-110
- Smooth pursuit and antisaccade eye movements in siblings discordant for schizophrenia.J Psychiatr Res. 2004; 38: 177-184
- Familial aggregation of eye-tracking endophenotypes in families of schizophrenic patients.Arch Gen Psychiatry. 2006; 63: 259-264
- Increased saccadic rate during smooth pursuit eye movements in patients at ultra high risk for developing a psychosis.Brain Cogn. 2010; 73: 215-221
- Schizophrenia, eye movements, and biocultural heterogeneity.Hum Biol. 1990; 62: 337-352
- SPEM impairment in drug-naive schizophrenic patients: Evidence for a trait marker.Biol Psychiatry. 1992; 32: 891-902
- A concordance study of three electrophysiological measures in schizophrenia.Am J Psychiatry. 2005; 162: 466-474
- Schizophrenia spectrum disorders and eye tracking dysfunction in singleton and multiplex schizophrenia families.Schizophr Res. 2003; 60: 33-45
- Specificity of smooth pursuit eye movement and visual fixation abnormalities in schizophrenia.Schizophr Res. 1991; 5: 135-144
- Fixation stability in schizophrenia, bipolar, and control subjects.Psychiatry Res. 2000; 97: 119-128
- The relation between antisaccade errors, fixation stability and prosaccade errors in schizophrenia.Exp Brain Res. 2008; 186: 273-282
- Eye movement deficits in schizophrenia: Investigation of a genetically homogenous Icelandic sample.Eur Arch Psychiatry Clin Neurosci. 2008; 258: 373-383
- Visual fixation and smooth pursuit eye movement abnormalities in patients with schizophrenia and their relatives.J Neuropsychiatry Clin Neurosci. 1995; 7: 197-206
- Fixation stability among schizophrenia patients.Neuropsychobiology. 1998; 38: 57-62
- Eye movements during the Rorschach test in schizophrenia.Psychiatry Clin Neurosci. 2002; 56: 409-418
- Visual processing of social context during mental state perception in schizophrenia.J Psychiatry Neurosci. 2008; 33: 34-42
- Visual scan paths are abnormal in deluded schizophrenics.Neuropsychologia. 1997; 35: 99-105
- Eye movements reflect impaired face processing in patients with schizophrenia.Biol Psychiatry. 1999; 46: 963-969
- Visual scanpaths to positive and negative facial emotions in an outpatient schizophrenia sample.Schizophr Res. 2002; 55: 159-170
- Eye movements in acute, chronic, and remitted schizophrenics.Biol Psychiatry. 1990; 27: 975-989
- Stability of exploratory eye movements as a marker of schizophrenia—a WHO multi-center study.Schizophr Res. 2001; 52: 203-213
- Global visual scanning abnormalities in schizophrenia and bipolar disorder.Schizophr Res. 2006; 87: 212-222
- Visual scan paths in first-episode schizophrenia and cannabis-induced psychosis.J Psychiatry Neurosci. 2007; 32: 267-274
- Eye movement studies on schizophrenics and their parents.Eur Neuropsychopharmacol. 1996; 6 (64–64)
- Visual scanpath dysfunction in first-degree relatives of schizophrenia probands: Evidence for a vulnerability marker?.Schizophr Res. 2004; 67: 11-21
- Impairment of exploratory eye movement in schizophrenia patients and their siblings.Psychiatry Clin Neurosci. 2008; 62: 487-493
- Diagnostic classification of schizophrenia by neural network analysis of blood-based gene expression signatures.Schizophr Res. 2010; 119: 210-218
- Structured Clinical Interview for DSM-IV Axis I Disorders—Patient Edition (SCID I/P, Version 2.0). New York State Psychiatric Institute, Biometrics Research Department, New York1997
- A polydiagnostic application of operational criteria in studies of psychotic illness: Development and reliability of the OPCRIT system.Arch Gen Psychiatry. 1991; 48: 764-770
- Selection bias in gene extraction on the basis of microarray gene-expression data.Proc Natl Acad Sci U S A. 2002; 99: 6562-6566
- Eye-tracking dysfunction in the affective psychoses and schizophrenia.Psychol Med. 1992; 22: 573-580
- An Introduction to the Bootstrap. Chapman and Hall/CRC, Boca Raton, FL1993
- Rank transformations as a bridge between parametric and nonparametric statistics.Am Statistician. 1981; 35: 124-129
- Statistical Power Analysis for the Behavioral Sciences. 2nd ed. Lawrence Erlbaum Associates, Mahwah, NJ1988
- Calculation of confidence intervals for noncentrality parameters.J Roy Stat Soc B. 1975; 37: 406-412
- Statistical Methods for Meta-Analysis. Academic Press, Orlando, FL1985
- Statistics for Psychologists. Holt, Rinehart and Winston, New York1963
- Design and Analysis: A Researcher's Handbook. Prentice Hall, Englewood Cliffs, NJ1991
- Estimating the dimension of a model.Ann Statist. 1978; 6: 461-464
- Classification and Regression Trees.Wadsworth & Brooks/Cole Advanced Books & Software, Monterey, CA1984
- Greedy function approximation: A gradient boosting machine.Ann Statistics. 2001; 29: 1189-1232
- Stochastic gradient boosting.Comput Stat Data Anal. 2002; 38: 367-378
Caruana R, Niculescu-Mizil A (2006): An empirical comparison of supervised learning algorithms. Proceedings of the 23rd International Conference on Machine Learning; Carnegie Mellon University, Pittsburgh, Pennsylvania; 25–29 Jun. 148:161–168.
- Probabilistic neural networks and the polynomial Adaline as complementary techniques for classification.IEEE Trans Neural Netw. 1990; 1: 111-121
- Enhancements to probabilistic neural networks.Neural Netw. 1992; 1: 761-768
- Prediction error estimation: A comparison of resampling methods.Bioinformatics. 2005; 21: 3301-3307
- Computerized analysis of eye movements as a function of age.Arch Gerontol Geriatr. 1996; 22: 261
Article Info
Publication History
Published online: May 24, 2012
Accepted:
April 3,
2012
Received in revised form:
April 2,
2012
Received:
August 27,
2011
Identification
Copyright
© 2012 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.
