Visual masking & schizophrenia

Abstract

Visual masking is a frequently used tool in schizophrenia research. Visual masking has a very high sensitivity and specificity and masking paradigms have been proven to be endophenotypes. Whereas masking is a powerful technique to study schizophrenia, the underlying mechanisms are discussed controversially. For example, for more than 25 years, masking deficits of schizophrenia patients were mainly attributed to a deficient magno-cellular system (M-system). Here, we show that there is very little evidence that masking deficits are magno-cellular deficits. We will discuss the magno-cellular and other approaches in detail and highlight their pros and cons.

Impaired conscious access and abnormal attentional amplification in schizophrenia

“…Schizophrenia is a serious psychiatric disorder that affects approximately ~1% of the population worldwide and causes positive symptoms, such as delusions and hallucinations, negative symptoms, including withdrawal from social interactions and daily life activities, cognitive impairments, and disorganization syndrome. Experimental studies of visual masking have reproducibly revealed an elevated threshold for the perception of masked visual stimuli in schizophrenia ( Butler et al 2003 ; Charles et al 2017 ; Dehaene et al 2003a ; Del Cul et al 2006 ; Green et al, 1999 , Green et al, 2011 ; Herzog et al 2004 ; Herzog and Brand 2015 ; Plomp et al 2013 ). For instance, in classical masking experiments in which the target-mask duration is manipulated, patients with schizophrenia typically need a longer delay between the two, compared to controls, to consciously perceive the target ( Charles et al 2017 ; Del Cul et al 2006 ).…”

Tobacco Use Decreases Visual Sensitivity in Schizophrenia

“…Thus, abnormalities in these pathways may cause direct losses of the perception of stimuli at specific spatial or temporal frequencies. Nonetheless, there is a suggestion that an overall deficit of visual pathways may be more likely ( Herzog and Brand, 2015 ).…”

“…Regardless of smoking status, SCZ patients present impairments in visual information processing, including motion perception, perceptual organization, spatial localization, temporal prediction, eye tracking, color perception, and visual contrast sensitivity ( Yee et al, 1987 ; Shuwairi et al, 2002 ; Butler et al, 2008 ; Levy et al, 2010 ; Herzog and Brand, 2015 ; Martin et al, 2017 ). The results of studies that investigated changes in visual sensitivity in SCZ have been controversial.…”

“…When dysfunction of these pathways occurs, there may be losses in signal amplification, as reported by Kéri et al (2000) , Butler et al (2005) , Chen (2011) , Schallmo et al (2015) , and others. This dual channel is further addressed in the section “Discussion.” However, other results suggest that overall dysfunction may be a more plausible approach than specific dysfunction of, for example, only the M-pathway ( Herzog et al, 2013 ; Herzog and Brand, 2015 ). For a broad discussion between the magno- and parvocellular pathways, see Skottun (2015) .…”

Electrophysiological correlates of visual backward masking in patients with bipolar disorder

“…Several candidate endophenotypes have been proposed for both schizophrenia and bipolar disorder (15,16). Endophenotypes based on visual processing are of particular relevance because of their excellent reproducibility, etiology-independence, and their contributions to higher cognitive impairments such as object recognition (17)(18)(19)(20). Visual backward masking (VBM) is such a candidate endophenotype for schizophrenia (21,22), especially the shine-through paradigm, which has a much higher sensitivity and specificity than most other perceptual and cognitive tasks (23).…”