Atypical scanpaths in schizophrenia: Evidence of a trait- or state-dependent phenomenon?

Atypical scanpaths in schizophrenia: Evidence of a trait- or state-dependent phenomenon?

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J Psychiatry Neurosci 2011;36(3):150-64

Sara A. Beedie, PhD; David M. St. Clair, MD, PhD; Philip J. Benson, PhD

Beedie, Benson — School of Psychology, College of Life Sciences and Medicine, University of Aberdeen, King’s College; St. Clair — School of Medicine and Dentistry, Division of Applied Medicine, University of Aberdeen, Clinical Research Centre, Royal Cornhill Hospital, Aberdeen, Scotland

Abstract

The development of trait markers of schizophrenia would represent an important advance in understanding the genetic architecture of the disease. To date, no candidate markers have satisfied all of the trait marker criteria, and many are not specific to the schizophrenia spectrum. Abnormalities in visual scanpaths are frequently reported in patients with schizophrenia and are emerging as a novel candidate for a schizophrenia biomarker. Here we review the suitability of scanpath measures as a target for trait marker research in schizophrenia. Papers reporting scanpath patterns in patients with schizophrenia were identified by PubMed and Google Scholar searches and by scanning reference lists in relevant articles. Search terms included “schizophrenia,” “psychosis,” “scanpath,” “scan path,” “fixation,” “saccade” and “eye movement.” Scanpath abnormalities afford impressive sensitivity and specificity and appear largely independent of psychotropic medications. Scanpaths may demonstrate some fluctuation with symptomatology and may be useful in illuminating illness state or subtypes. However, there is evidence that viewing behaviours remain atypical regardless of symptom remission and may be present in unaffected relatives of individuals with schizophrenia. This research is in its early stages, and further investigation regarding patterns of inheritance is required. Our findings support scanpath measures as a favourable topic for further investigation as a trait marker.


Submitted Nov. 27, 2009; Revised June 14, Aug. 20, 2010; Accepted Sept. 1, 2010.

Acknowledgments: This review is partly based on a doctoral dissertation completed by Dr. Beedie under the supervision of Dr. Benson and Professor St. Clair. During the preparation of this manuscript, salary support for Dr. Beedie was provided by the Chief Scientist Office (CZB-4-734, awarded to Dr. Benson) and previously by the European Commission (SGENE, awarded to Professor St. Clair).

Competing interests: As above.

Contributors: Drs. Beedie and Benson acquired the data and wrote the article. All authors designed the review, analyzed the data, reviewed the article and approved its publication.

DOI: 10.1503/jpn.090169

Correspondence to: Dr. S.A. Beedie, School of Psychology, College of Life Sciences and Medicine, University of Aberdeen, William Guild Bldg., King’s College, Aberdeen, Scotland, AB24 3FX; s.beedie@abdn.ac.uk