Recent updates of eye movement abnormalities in patients with schizophrenia: A scoping review

Abstract

Aim Although eye‐tracking technology expands beyond capturing eye data just for the sole purpose of ensuring participants maintain their gaze at the presented fixation cross, gaze technology remains of less importance in clinical research. Recently, impairments in visual information encoding processes indexed by novel gaze metrics have been frequently reported in patients with schizophrenia. This work undertakes a scoping review of research on saccadic dysfunctions and exploratory eye movement deficits among patients with schizophrenia. It gathers promising pieces of evidence of eye movement abnormalities in attention‐demanding tasks on the schizophrenia spectrum that have mounted in recent years and their outcomes as potential biological markers. Methods The protocol was drafted based on PRISMA for scoping review guidelines. Electronic databases were systematically searched to identify articles published between 2010 and 2020 that examined visual processing in patients with schizophrenia and reported eye movement characteristics as potential biomarkers for this mental illness. Results The use of modern eye‐tracking instrumentation has been reported by numerous neuroscientific studies to successfully and non‐invasively improve the detection of visual information processing impairments among the screened population at risk of and identified with schizophrenia. Conclusions Eye‐tracking technology has the potential to contribute to the process of early intervention and more apparent separation of the diagnostic entities, being put together by the syndrome‐based approach to the diagnosis of schizophrenia. However, context‐processing paradigms should be conducted and reported in equally accessible publications to build comprehensive models.

Lower Hippocampal Volume in Patients with Schizophrenia and Bipolar Disorder: A Quantitative MRI Study

“…Because SZ and BD share the biological basis of psychoses [1][2][3][4][5][6][7][8][9][10][11][51][52][53][54][55][56][57] and they sometimes present similar pathologies, detection of anatomical and functional biomarkers that differentiate SZ and BD patients is crucial for the optimization of pharmacological and psychosocial treatments for each condition. The results of our ROC analyses suggest that the right hippocampal volume is a potential marker for differentiation between SZ and BD.…”

“…Patients with schizophrenia (SZ) and bipolar disorder (BD) share many biological features, including genetic architecture (e.g., [1,2]) and structural (e.g., [3]) and functional brain abnormalities (e.g., [4][5][6][7][8][9][10]). Clinically, it is an urgent issue to accurately diagnose and distinguish between the two diseases for providing appropriate treatment and improving patient outcome, as they sometimes present similar pathologies.…”

Contribution of Eye-Tracking to Study Cognitive Impairments Among Clinical Populations

“…The purpose is straightforward, to have real-time insights into specific responses in the brain and nervous system, resulting from the presentation of a stimulus ( Lim, 2018 ). Especially, eye-tracking technique provides a relatively low-cost and sensitive indicator for initial orienting, shift, and maintenance of attention ( Caseras et al, 2007 ; Kou et al, 2016 ; Wolf et al, 2021 ). Since eye-movements provide realistic evidence of where participants are likely to look at Bird et al (2012) ; Morii and Sakagami (2015) ; van der Laan et al (2015) ; Wolf et al (2018 , 2019) , this might be a valid reason why some research groups choose precisely the eye-tracking technique to study attentional biases among individuals with body dysmorphic disorder (BDD) ( Kou et al, 2016 ), which is characterized by repetitive behaviors and/or mental acts occurring in response to preoccupations with perceived defects or flaws in physical appearance ( American Psychiatric Association, 2013 ).…”

“…Hence, to address the investigation on how clinical populations approach real-life functioning tasks, new research questions require analysis of decision-making paradigms that may provide informative attentional scan-paths and explorative eye-movements, beyond the quantification of fixations and saccades ( Wolf et al, 2021 ). Furthermore, since decision-making paradigms fundamentally relate to the individual’s homeostatic processing, it seems straightforward to actively translate them into clinically performed experiments, supported with non-invasive eye-tracking devices.…”

“…Since eye-tracking instruments objectively reflect action selection, based on decision maker’s attention, information processing capabilities, and motivated cognition processes ( Deubel and Schneider, 1996 ; Ernst and Paulus, 2005 ; Simion and Shimojo, 2006 ; Glaholt and Reingold, 2009 ; Markkula, 2015 ; van der Laan et al, 2015 ; Gerbella et al, 2017 ; Onuma et al, 2017 ; Wolf et al, 2018 , 2019 ), it should not be overlooked that relatively cost-effective and non-invasive eye-tracking devices are becoming vital instruments exposing the mechanism of cognitive and perceptual disturbances among clinical populations ( Tseng et al, 2013 ; Türkan et al, 2016 ; Sawada et al, 2017 ; Morita et al, 2020 ; Wolf et al, 2021 ).…”