Windows to the soul: vision science as a tool for studying biological mechanisms of information processing deficits in schizophrenia

Abstract

Cognitive and information processing deficits are core features and important sources of disability in schizophrenia. Our understanding of the neural substrates of these deficits remains incomplete, in large part because the complexity of impairments in schizophrenia makes the identification of specific deficits very challenging. Vision science presents unique opportunities in this regard: many years of basic research have led to detailed characterization of relationships between structure and function in the early visual system and have produced sophisticated methods to quantify visual perception and characterize its neural substrates. We present a selective review of research that illustrates the opportunities for discovery provided by visual studies in schizophrenia. We highlight work that has been particularly effective in applying vision science methods to identify specific neural abnormalities underlying information processing deficits in schizophrenia. In addition, we describe studies that have utilized psychophysical experimental designs that mitigate generalized deficit confounds, thereby revealing specific visual impairments in schizophrenia. These studies contribute to accumulating evidence that early visual cortex is a useful experimental system for the study of local cortical circuit abnormalities in schizophrenia. The high degree of similarity across neocortical areas of neuronal subtypes and their patterns of connectivity suggests that insights obtained from the study of early visual cortex may be applicable to other brain regions. We conclude with a discussion of future studies that combine vision science and neuroimaging methods. These studies have the potential to address pressing questions in schizophrenia, including the dissociation of local circuit deficits vs. impairments in feedback modulation by cognitive processes such as spatial attention and working memory, and the relative contributions of glutamatergic and GABAergic deficits.

Reduced contextual effects on visual contrast perception in schizophrenia and bipolar affective disorder

“…Our results align with a growing literature showing impaired visual context processing in SZ (Butler et al , 2008, Notredame et al , 2014, Phillips and Silverstein, 2013, Yoon et al , 2013). Some of these deficits may be specific to peripheral vision, such as abnormal temporal processing (Chen et al , 2014) and spatial crowding (Kraehenmann et al , 2012, but see Robol et al , 2013).…”

“…It has been suggested that studying these impairments may provide insight into the neural underpinnings of this disorder; by precisely characterizing visual deficits in SZ, one may be able to attribute them to specific neural mechanisms (Butler et al , 2008, Notredame et al , 2014, Phillips and Silverstein, 2013, Yoon et al , 2013). A number of recent studies have shown weaker surround suppression among SZ patients compared with healthy controls (HC; Dakin et al , 2005, Robol et al , 2013, Schallmo et al , 2013, Seymour et al , 2013, Tadin et al , 2006, Tibber et al , 2013, Yang et al , 2013a, b, Yoon et al , 2009), but see (Barch et al , 2012, Chen et al , 2008).…”

On the functions, mechanisms, and malfunctions of intracortical contextual modulation

“…In contrast to these findings is evidence that suppression of motion information in schizophrenia may in some cases be increased compared to healthy controls (Chen, Norton and Ongur, 2008). Overall, however, there is ample evidence that surround suppression is often impaired in schizophrenia (Yoon et al, 2013).…”

The Role of Hyperspectral Imaging: A Literature Review

“…It is also called feature subset selection. Mosaic based images [25] which are merged into a particular hyperspectral image, is used for the data analysis and classification algorithms.…”