Summary: Schizophrenics have a difficult time distinguishing between light strength and shapes and textures due to impaired compare belief. This deficit does stem from disruptions in cholinergic neurotransmission, a key neurological system in the illness.
Contrast sensitivity tests may be a non-invasive marker for psychosis diagnosis and monitoring, according to researchers. The study also makes a point about the possible effects of effortful lapses and medications, stressing the need for further investigation to identify these causes and confirm the findings.
Important Information:
- Impaired Contrast Perception: Schizophrenia patients challenge to find light depth differences, impacting physical tasks like encounter recognition and navigation.
- Serotonin Connection: Lower glutamate levels does explain a decrease in brain processing contrast-related neural activity.
- Contrast sensitivity tests may aid in the diagnosis of patients with severe hormone dysfunction for focused treatments.
Origin: University of Barcelona
Schizophrenia is a serious mental condition that affects around 1 % of the country’s population. Researchers at the University of Barcelona have discovered a difference between dementia and other people’s perceptions.
These individuals have an impaired ability to distinguish between adjacent areas in terms of lighting power, which aids in the identification of designs, textures, and details in the environment.
These findings may aid in the identification of gaps in the neuronal and mathematical mechanisms of schizophrenia. Additionally, this visual shift might be used as a possible non-invasive marker for the treatment or checking of this disorder.
The authors emphasize the need for further research to verify this relationship and to establish the contribution of various factors, such as medications, to this visual disturbance.
The article, published in the journal , Schizophrenia Bulletin, is signed by researchers Daniel Linares and Cristina de la Malla, together with master’s student Aster Joostens, from the Vision and Control of Action Group of the , Faculty of Psychology , and the UB Institute of Neurosciences ( UBneuro ).
A key sign of physical function
There are changes in how people think and act, such as losing touch with reality, delusions, or delusions, but there are also changes in how they perceive physical stimuli, such as color or distinction perception deficits.
Understanding these anomalies may help us understand how data handling issues contribute to the symptomatic symptoms of schizophrenia.
The research group, a member of the Department of Cognition, Development, and Educational Psychology, states that” compare view is one of the most important abilities of eyesight, as it makes it possible for us to understand the environment and the objects in it, which can impair daily tasks like moving through space, recognizing faces, or reading.”
The levels of serotonin, a neurotransmitter believe to play a significant role in the disease’s pathogenesis, may be related to these altered neurological mechanisms.  ,
” A decreased level of this hormone can result in decreased neural activity in the comparison control regions of the brain. Thus, a decrease in contrast sensitivity, although not of great scale, may represent an actual damage in the glutamatergic method of affected people”, note the experts.
Contrast sensitivity tests may be a useful tool for identifying people with schizophrenia who exhibit more severe function in this hormone pathway. These people, for instance, might make good prospects for clinical trials to evaluate medications that specifically target glutamatergic signaling, they claim.
These people may have trouble identifying variations in light intensity between opposite areas, which may make it impossible for them to accurately perceive their surroundings and objects, according to a review of more than 600 studies.
Unravelling the effects of medical treatment and treatment
The findings of the study indicate that people with schizophrenia have a significant impairment in contrast perception, but that this impairment may also be caused by other factors.
According to the authors, “in the study, we have identified a relationship with the amount of antipsychotic medication administered,” suggesting that the impairment may be at least partially due to the effects of the medication.
Additionally, it would be important to know in more detail what the role of attention is since none of the studies examined have examined whether patients may perform the test with less concentration despite the fact that these individuals are known to be more prone to attentional lapses.
A deficit in a perceptual or cognitive task may result from a particular impairment in the processes that the task is intended to assess, but it may also reflect a more generalized cognitive impairment, such as attention lapses, which can be estimated by the proportion of errors in simple tests, they say.
The fact that the studies did not consider this aspect “opens up the possibility that these lapses contribute to the deficit that has been observed,” they add.
Therefore, the researchers emphasize the need for further studies with experimental designs that allow the uncoupling of perceptual attention deficits and that include populations with psychotic symptoms, with little or no medication, in order to determine whether the impairment is directly caused by the illness and as a biomarker of psychosis.
” In this line, we are currently measuring contrast sensitivity in patients with anti-NMDAR encephalitis, a disease in which there is also psychotic symptomatology, using a paradigm that includes control tests to monitor their attention”, they conclude.
About this news about visual neuroscience and schizophrenia
Author: Rosa Martínez
Source: University of Barcelona
Contact: Rosa Martínez – University of Barcelona
Image: The image is credited to Neuroscience News
Original Research: Open access.
” A systematic review and meta-analysis on contrast sensitivity in schizophrenia” by Daniel Linares et al. Schizophrenia Bulletin
Abstract
A systematic review and meta-analysis on contrast sensitivity in schizophrenia
Background and Hypothesis
Understanding mental disorders’ perceptual changes can aid in the identification of neural and computational anomalies. In schizophrenia, perceptual alterations have been reported for many visual features, including a deficit in contrast sensitivity, a key measure of visual function. The evidence supporting this deficit, however, has not been comprehensively synthesized.
Study Design
We conducted a thorough analysis and meta-analysis of studies comparing contrast sensitivity in healthy controls and people with schizophrenia. Our search identified 46 studies, of which 43 focused on chronic patients.
Study Results
We found that patients with chronic schizophrenia have reduced contrast sensitivity ( g = 0.74, 95 % CI, 0.55 to 0.93,  , P = 8.2 × 10−10 ). However, we found evidence that the deficit could be driven by medication.
Additionally, none of the studies made attentional lapse estimates, which raises the question of whether a potentially higher rate of lapses in patients accounts for the observed deficit.
Additionally, only two studies thoroughly assessed visual acuity, which makes it difficult to comprehend how spatial frequency affects the observed deficit.
Conclusions
While we found a significant contrast sensitivity deficit in chronic schizophrenia patients, the impact of attentional lapses and medication on this impairment is still undetermined. We make a number of suggestions for upcoming research to help us understand the underlying mechanisms causing this deficit.
