Relationship between exploratory eye movements and brain morphology in schizophrenia spectrum patients

Abstract

The exploratory eye movements of schizophrenia patients and their relatives have been shown to differ from those of patients without schizophrenia and healthy controls. However the mechanism of exploratory eye movement disturbances in schizophrenia patients remains elusive. We investigated the relationship between the exploratory eye movements and brain morphology in 39 schizophrenia spectrum patients. Voxel-based morphometric analysis on three-dimensional magnetic resonance imaging was conducted by means of statistical parametric mapping 99. The decrease in the responsive search score, which is the total number of sections on which the eyes fixed in response to questioning in a comparison task, was significantly correlated with the decreased gray matter in the right frontal eye field (rFEF) including the right supplementary eye field (rSEF), right parietal eye field (rPEF), and right inferior frontal region. These results suggest that disturbance in exploratory eye movement in schizophrenia spectrum patients may be related to neural network dysfunction in FEF, SEF and PEF, which are the eye movement related areas, and in the inferior frontal region that may be related to information organization.

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

“…In 2 studies, the scanpaths of individuals with schizophrenia receiving neuroleptics did not differ from those of never-medicated patients (cross sectional design, 48 longitudinal design 41,48 ). Other researchers have found no influence of medication type (typical v. atypical neuroleptics 51,62 ) or duration 74 on scanpath variables. Evidence that antipsychotic medications may reduce abnormalities in viewing behaviour also suggests that restricted scanning is not a consequence of neuroleptic treatment.…”

“…patterns in individuals with schizophrenia and an unaffected control viewer. A central role of frontal lobe pathologies in abnormal scanning is supported by neuroimaging findings, 73,74 similarities between scanpaths of patients with schizophrenia and individuals with frontal lobe lesions, 54,75,76 correlations with neuropsychological performance 56 and an association with negative symptoms, which in turn are linked with prefrontal dysfunction. 77 Scanpath abnormalities may represent an epiphenomenon of a more basic dysfunction in oculomotor control that is assessed by more established putative trait markers in individuals with schizophrenia.…”

“…38,42,45,46,51,53,54,56,58,59,73,74,90 Although many of these reports are based on post hoc analyses, the findings are supported by comparisons of neurolepticnaïve patients with patients receiving regular neuroleptic treatment in both cross-sectional and longitudinal study designs. In 2 studies, the scanpaths of individuals with schizophrenia receiving neuroleptics did not differ from those of never-medicated patients (cross sectional design, 48 longitudinal design 41,48 ).…”

Neuroanatomical Circuitry Associated with Exploratory Eye Movement in Schizophrenia: A Voxel-Based Morphometric Study

“…It has been suggested that in schizophrenic patients with cortical atrophy [28], modulation processing may not be suitable because it could have widespread effects on voxel signal intensities and may result in less consistent spatial localization of gray matter volume differences from sample to sample [29], [30]. Besides, the analysis of unmodulated data in schizophrenia is fertile [29], [31] and has been successfully conducted to explore the relationship between EEM and brain morphology in schizophrenia [20]. Thus we only used unmodulated data for GMD analysis in the present study.…”

“…However, studies on exploring the underlying neuropathological mechanism of the EEM dysfunction in schizophrenia were relatively sparse. A pioneer study exploring the relationship between the EEM and brain morphology has presented that RSS was significantly related to gray matter density (GMD) in the right frontal eye field (rFEF) and right inferior frontal region in schizophrenia-spectrum patients [20]. The study increased the understanding of EEM abnormalities.…”