Visuospatial encoding deficits and compensatory strategies in schizophrenia revealed by eye movement analysis during a working memory task

Abstract

encoding deficits and compensatory strategies in schizophrenia revealed by eye movement analysis during a working memory task.Objective: To investigate scanpath abnormalities during the encoding of static stimuli in schizophrenia and their interaction with visuospatial working memory (VSWM) dysfunction. Methods: Outpatients with schizophrenia and control subjects were asked to encode a static pattern for subsequent recognition after a short delay. We measured the number of correct and incorrect choices. We also assessed the number and the distribution of fixations, the scanning time in specific regions of interest (ROIs) and the head movements during the encoding of the stimuli. The distributions of fixations and scanning time in definite ROIs during the discrimination of the correct pattern from the foils were also measured. Results: Patients recognised fewer correct patterns than controls. Correct trials in patients were characterised by a specific exploration of the central part of the stimulus during its presentation, whereas this feature was absent in incorrect trials. However, the scanning time and the numbers of fixations and head movements during encoding were similar in both groups and unrelated to recognition accuracy. In both groups, correct trials were associated with a selective exploration of the correct pattern amongst the six possibilities during recognition. Furthermore, patients gave more attention to incorrect patterns with a leftmost element identical to that of the correct response and also those approximating its global structure. Conclusion: Patients showed a VSWM deficit independent of oculomotor dysfunctions and head movements during encoding. Patients' correct trials were related to specific scanning during encoding and discrimination phases. Analysis of these patterns suggests that patients try to compensate for reduced VSWM ability by using specific encoding strategies.

Comparison of Visuospatial and Verbal Abilities in First Psychotic Episode of Schizophrenia Spectrum Disorder: Impact on Global Functioning and Quality of Life

“…Visuospatial impairment can negatively affect various daily activities from the most common, such as watching TV or reading a book, to the most complex, including social interactions (visual recognition of social signals), and recognition of territorial boundaries (interpersonal space; Cummings and Mega, 2003 ). SZ subjects exhibit impaired performance in a wide range of VIS functions, from the most basic level of visual perception to more complex visuospatial processing and navigation abilities (e.g., Stuve et al, 1997 ; Doniger et al, 2001 ; Butler et al, 2005 ; Hanlon et al, 2006 ; Piskulic et al, 2007 ; Weniger and Irle, 2008 ; Cocchi et al, 2009 ; Folley et al, 2010 ; Landgraf et al, 2010 ; Fajnerová et al, 2014 ). This decline in VIS performance is already present in the first episode of schizophrenia and performance further deteriorates over time, predicting poor outcome (Stirling et al, 2003 ).…”

Imaging human brain networks to improve the clinical efficacy of non-invasive brain stimulation

“…Schizophrenia is a severe mental illness commonly associated with trait deficits in cognitive functions like working memory (Mathes et al, 2005;Cocchi et al, 2009aCocchi et al, , 2009bCocchi et al, , 2009cDeserno et al, 2012). Such deficits have been consistently associated with altered lateral prefrontal activity (Tan et al, 2005).…”

Vision, spatial cognition and intellectual disability

“…Disturbed eye movements are commonly observed in many psychiatric illnesses, such as schizophrenia (see Cocchi et al, 2009). Gaze direction is an important social signal and altered control might be linked to impairments in social or cognitive processes as well.…”