Remediation of Visual Processing Impairments in Schizophrenia: Where We Are and Where We Need to Be

Systematic review and meta-analysis of early visual processing, social cognition, and functional outcomes in schizophrenia spectrum disorders

Non-affective psychotic disorders are marked by cognitive and sensory processing abnormalities, including in early visual processing and social cognition. Understanding the relationships between these deficits and their impact on daily-life functional outcomes may help to improve outcomes in affected individuals. This systematic review and meta-analysis aimed to summarise the existing evidence on the relationships between early visual processing, social cognition, and functional outcomes, and to assess the evidence regarding the mediating role of social cognition in the association between early visual processing and functional outcomes in individuals with schizophrenia spectrum disorders. A comprehensive search across five databases identified 364 potentially eligible studies, with eight articles meeting all inclusion criteria. Meta-analytic techniques were employed to synthesise effect sizes and assess a meta-mediation model. Three random-effects meta-analyses revealed significant associations between all three domains of interest. Social cognition partially mediated the relationship between early visual processing and functional outcomes. The direct effect of early visual processing on functional outcomes remained significant, albeit with a reduced effect size. The findings suggest that interventions targeting both early visual processing and social cognition concurrently may improve functional outcomes more effectively than focusing on either domain alone.

Spatial frequency processing and its modulation by emotional content in severe alcohol use disorder

RATIONALE

Visuo-perceptive deficits in severe alcohol use disorder (SAUD) remain little understood, notably regarding the respective involvement of the two main human visual streams, i.e., magnocellular (MC) and parvocellular (PC) pathways, in these deficits. Besides, in healthy populations, low-level visual perception can adapt depending on the nature of visual cues, among which emotional features, but this MC and PC pathway adaptation to emotional content is unexplored in SAUD.

OBJECTIVES

To assess MC and PC functioning as well as their emotional modulations in SAUD.

METHODS

We used sensitivity indices (d') and repeated-measures analyses of variance to compare orientation judgments of Gabor patches sampled at various MC- and PC-related spatial frequencies in 35 individuals with SAUD and 38 matched healthy controls. We then explored how emotional content modulated performances by introducing neutral or fearful face cues immediately before the Gabor patches and added the type of cue in the analyses.

RESULTS

SAUD patients showed a general reduction in sensitivity across all spatial frequencies, indicating impoverished processing of both coarse and fine-scale visual content. However, we observed selective impairments depending on facial cues: individuals with SAUD processed intermediate spatial frequencies less efficiently than healthy controls following neutral faces, whereas group differences emerged for the highest spatial frequencies following fearful faces. Altogether, SAUD was associated with mixed MC and PC deficits that may vary according to emotional content, in line with a flexible but suboptimal use of low-level visual content. Such subtle alterations could have implications for everyday life's complex visual judgments.

Cognitive function mediates the relationship between visual contrast sensitivity and functional outcome in schizophrenia

BACKGROUND

Individuals with schizophrenia exhibit deficits in visual contrast processing, though less is known about how these deficits impact neurocognition and functional outcomes. This study investigated effects of contrast sensitivity (CS) on cognition and capacity for independent living in schizophrenia.

METHODS

Participants were 58 patients with schizophrenia (n = 49) and schizoaffective disorder (n = 9). Patients completed a psychophysical paradigm to obtain CS with stimuli consisting of grating patterns of low (0.5 and 1 cycles/degree) and high spatial frequencies (4, 7, 21 cycles/degree). Patients completed the MATRICS Consensus Cognitive Battery and Wechsler Adult Intelligence Scales, Third Edition to assess cognition, and the problem-solving factor of the Independent Living Scales to assess functional capacity. We computed bivariate correlation coefficients for all pairs of variables and tested mediation models with CS to low (CS-LSF) and high spatial frequencies (CS-HSF) as predictors, cognitive measures as mediators, and capacity for independent living as an outcome.

RESULTS

Cognition mediated the relationship between CS and independent living with CS-LSF a stronger predictor than CS-HSF. Mediation effects were strongest for perceptual organization and memory-related domains. In an expanded moderated mediation model, CS-HSF was found to be a significant predictor of independent living through perceptual organization as a mediator and CS-LSF as a moderator of this relationship.

CONCLUSION

CS relates to functional capacity in schizophrenia through neurocognition. These relationships may inform novel visual remediation interventions.

Early Visual Processing Is Associated With Social Cognitive Performance in Recent-Onset Schizophrenia

BACKGROUND

Early-stage visual processing deficits are evident in chronic schizophrenia. Consistent with a cascade model of information processing, whereby early perceptual processes have downstream effects on higher-order cognition, impaired visual processing is associated with deficits in social cognition in this clinical population. However, the nature of this relationship in the early phase of illness is unknown. Here, we present data from a study of early visual processing and social cognitive performance in recent-onset schizophrenia (ROSz).

METHOD

Thirty-two people with ROSz and 20 healthy controls (HC) completed a visual backward masking task using stimuli of real world objects (Object Masking) to assess early-stage (i.e., 0-125 ms post-stimulus onset) visual processing. Subjects also completed two tasks of social cognition, one assessing relatively low-level processes of emotion identification (Emotion Biological Motion, EmoBio), and another assessing more complex, higher-order theory of mind abilities (The Awareness of Social Inference Test, TASIT). Group differences were tested with repeated measures ANOVAs and t-tests. Bivariate correlations and linear regressions tested the strength of associations between early-stage visual processing and social cognitive performance in ROSz.

RESULTS

For Object Masking, the mask interfered with object identification over a longer interval for ROSz than for HC [F (3.19, 159.35) = 8.51, p < 0.001]. ROSz were less accurate on the EmoBio task [t (50) = -3.36, p = 0.001] and on the TASIT compared to HC [F (1, 50) = 38.37, p < 0.001]. For the TASIT ROSz were disproportionately impaired on items assessing sarcasm detection [F (1, 50) = 4.30, p = 0.04]. In ROSz, better Object Masking performance was associated with better social cognitive performance [r EmoBio = 0.45, p < 0.01; r TASIT = 0.41, p < 0.02]. Regression analyses did not provide significant support for low-level social cognition mediating the relationship between visual processing and high-level social cognition.

CONCLUSION

Early-stage visual processing, low-level social cognition, and high-level social cognition were all significantly impaired in ROSz. Early-stage visual processing was associated with performance on the social cognitive tasks in ROSz, consistent with a cascade model of information processing. However, significant cascading effects within social cognition were not supported. These data suggest that interventions directed at early visual processing may yield downstream effects on social cognitive processes.

Localization of Early-Stage Visual Processing Deficits at Schizophrenia Spectrum Illness Onset Using Magnetoencephalography

Impairments in early-stage visual processing are observed in chronic psychosis. However, their presence, localization within the brain, and contribution to cognitive symptoms remain less well established early in disease course. The present study utilized magnetoencephalography (MEG) to examine sensory responses within primary visual cortex (V1). MEG was recorded from 38 individuals diagnosed with a schizophrenia spectrum illness at first psychotic episode (FESz) and 38 matched healthy controls (HC) during visual search tasks. The inverse solution for cortical activity contributing to the M100 visual evoked field was derived. Task performance and V1 activation were compared between groups. FESz exhibited a reduced V1 response relative to HC. This group deficit, however, was selective for the left hemisphere (LH). A similar interaction was observed for response time with FESz exhibiting slower responses to right visual field targets, a difference not observed among HC. Among FESz, larger LH V1 activity was associated with larger hallucination subscale scores on the Scale for the Assessment of Positive Symptoms. Early-stage visual processing deficits localized to V1 are present at disease onset in the schizophrenia spectrum. This impairment appears to be restricted to the LH, consistent with previous reports detailing a predominantly LH disease process in early psychosis, and activity within this region was associated with an increased experience of hallucinations. These findings detail the cortical responses contributing to visual processing impairments and their relationship with symptoms at disease onset, advancing our understanding of their developmental trajectory over the course of psychotic illness.