Introduction

The speaker introduces the topic of recent flash ERG data collected in people with schizophrenia and explains why studying vision in schizophrenia is important.

• Schizophrenia is a severe psychotic disorder that affects about 1% of the population worldwide.

• Visual problems are common in patients with schizophrenia, including distortions in vision, changes in depth perception, and problems with facial emotion interpretation and reading.

• These visual problems can be found even in children and young adults at high risk for developing the disorder.

• Studying vision in schizophrenia can help us better understand the pathophysiology of the disorder and its relationship to visual function.

Recent Data on Flash ERG Abnormalities

The speaker discusses recent data collected at Rutgers on flash ERG abnormalities in people with schizophrenia.

• Flash ERG is a technique used to measure electrical activity in the retina in response to flashes of light.

• Recent data from Rutgers has shown that people with schizophrenia have abnormal flash ERG responses compared to healthy controls.

• These abnormalities are related to specific symptoms of schizophrenia, such as hallucinations and delusions, suggesting a link between visual processing impairments and the pathophysiology of the disorder.

Why Study Vision?

The speaker explains why studying vision is important when studying schizophrenia.

• Visual problems are common in patients with schizophrenia, but have been studied less than auditory problems.

• However, distortions in vision are reported by about 60% of patients before they receive medication for their symptoms.

• Laboratory studies have shown impairments across various levels of visual processing, including low-level changes like contrast sensitivity and mid-level changes like perceptual organization.

• Visual problems are also related to other aspects of functioning, such as poor visual memory and difficulty interpreting facial emotion or processing faces in general.

Common Visual Problems in Schizophrenia

The speaker discusses common visual problems reported by patients with schizophrenia.

• Patients with schizophrenia commonly report distortions in vision, such as changes in brightness or depth perception.

• These changes can be scary and lead to difficulty walking or navigating the environment.

• Laboratory studies have shown impairments across various levels of visual processing, including low-level changes like contrast sensitivity and mid-level changes like perceptual organization.

• Visual problems are also related to other aspects of functioning, such as poor visual memory and difficulty interpreting facial emotion or processing faces in general.

Relationship Between Visual Problems and Other Aspects of Functioning

The speaker discusses the relationship between visual problems and other aspects of functioning in patients with schizophrenia.

• Patients with visual problems tend to perform more poorly in the real world, respond more poorly to treatment, and have difficulty interpreting facial emotion or processing faces in general.

• These problems are not just related to medication use; they can also be found in children and young adults at high risk for developing the disorder.

• Ocular abnormalities like strabismus and poor visual acuity at a young age can predict the development of schizophrenia later on.

The Role of the Retina in Schizophrenia

In this section, the speaker discusses the role of the retina in schizophrenia and how studying it can provide insights into the disorder.

Early Visual Processing

• There are debates between two different camps on whether changes in visual processing occur in the visual cortex or prefrontal cortex.

• Recent studies suggest that some issues may actually be as early as the retina or thalamus.

• Studying the retina has advantages such as being non-invasive, quick, and using similar neurotransmitters as those found in the brain.

Retinal Ganglion Cells

• Retinal ganglion cells synapse in the brain and provide early input into magnocellular pathways which have been implicated as deficient in schizophrenia.

• OCT studies show retinal nerve fiber layer thinning and retinal venule widening in schizophrenia.

• The widest retinal venules were found to be associated with more psychotic symptoms as children who later developed schizophrenia.

ERG Abnormalities

• Several studies indicate ERG abnormalities (both A and B wave amplitude and latency) in schizophrenia.

• Flash ERG has been studied extensively with over 100 patients involved but there are no published studies yet of pattern ERG in schizophrenia.

• Data from flash ERG tests on 25 patients with schizophrenia showed significant reduction in A wave amplitude across three light adaptive tests.

Photopic ERG Wave

• Photopic ERG wave consists of A and B waves.

• Quentin Davis designed a minimal battery for testing that had broad coverage of conditions shown to differentiate people with schizophrenia from healthy control subjects or those with bipolar disorder who often take similar medications.

• Significant reduction was found in A wave amplitude during a relatively intense stimulus test at 1 Hertz presentation rate, and also during a different test with a red flash against blue background at a weaker stimulus but faster presentation rate.

ERG Data in Schizophrenia

In this section, the speaker discusses the results of electroretinogram (ERG) tests conducted on individuals with schizophrenia.

Reduced Amplitude in Schizophrenia

• Two conditions showed significant differences between controls and schizophrenia groups.

• The schizophrenia group had weaker responses to higher intensity stimuli compared to controls.

Relationship with Visual Function

• No relationship was found between ERG variables and visual function tests except for a reduced A-wave amplitude related to lower peak contrast sensitivity.

Correlation with Symptoms

• Negative or deficit symptoms correlated significantly with ERG amplitudes associated with weaker stimuli.

• Reacting less to light stimulus is related to people who show more negative symptoms.

Mismatch Negativity Data in Schizophrenia

In this section, the speaker discusses how the results of mismatch negativity data are similar to those of ERG tests in individuals with schizophrenia.

Weaker Response to Deviation

• People with schizophrenia show a much weaker response to deviation from regular patterns.

• As deviation becomes larger, the difference between schizophrenia and healthy participants gets larger as well.

Interpretation of Results

• The ability to represent differences in stimulus intensity is smaller in individuals with schizophrenia.

• This may lead to a decreased ability to appreciate the significance of stimuli.

Negative Symptoms in Schizophrenia

In this section, the speaker discusses negative symptoms in schizophrenia and their correlation with ERG amplitudes.

Definition of Negative Symptoms

• Negative symptoms signify an absence of something that should be there, such as flat facial effect or lack of pleasure.

• They are a significant cause of disability in individuals with schizophrenia.

Correlation with ERG Amplitudes

• ERG amplitudes associated with weaker stimuli correlated significantly with negative or deficit symptoms.

• This was observed on three variables.

ERG Changes in Schizophrenia

In this section, the speaker discusses the findings of a study on ERG changes in schizophrenia and their potential implications for understanding the disorder.

Findings of the Study

• The study found group differences in photoreceptor and bipolar cells in patients with schizophrenia.

• ERG data can be collected using a portable device called RetEval that does not require pupillary dilation or corneal contact electrodes, making it more tolerable for patients with severe psychiatric symptoms.

• ERG data may be useful as potential predictors of treatment response or impending relapse in patients with schizophrenia.

• ERG changes appear to be related to problems in low-level vision in schizophrenia, which could help explain reduced M pathway activity.

Implications of the Findings

• The findings suggest common neural mechanisms between retinal responses and development of symptoms at the behavioral level.

• The study has implications for understanding what is going on in schizophrenia and could lead to large grants being obtained by many people.

Understanding Schizophrenia

In this section, the speakers discuss the unique aspects of schizophrenia and how it differs from other neurological disorders. They also talk about the challenges in identifying biomarkers for schizophrenia.

Unique Aspects of Schizophrenia

• The reduction in response gain across increasing intensity has not been shown to occur in neurological disorders.

• There is no biomarker for schizophrenia, and it may be a heterogeneous category with potentially a hundred different conditions.

• Researchers are trying to identify things that are reliably associated with schizophrenia to understand its physiology better and predict treatment response and relapse.

Differentiating Psychiatric Diagnoses

• Researchers are trying to identify markers that can differentiate between psychiatric diagnoses such as bipolar disorder, major depression, and schizophrenia.

• The challenge is determining whether symptoms related to psychosis or diagnosis since only a few people with bipolar disorder have psychotic symptoms at the time of testing.

Dopamine Hypothesis

• Excess midbrain dopamine in the ventral tegmental and substantial Niagra occurs during early onset of schizophrenia.

• Midbrain dopamine levels decrease as illness becomes chronic.

• Elevated dopamine in the midbrain alone is not enough to cause schizophrenia; it's a combination of genetic predisposition, environmental stressors, chronic social defeat, inability to escape stress, and possibly drug use.

Medication Effects on Synaptic Activity

• There is limited data on how medication suppresses synaptic activity between neurons.

Medication and Psychiatric Acute Care Units

The effect of medication on psychiatric acute care units is discussed, with a study from Hungary in 2008 showing that medication can improve symptoms but does not account for the main difference between patients.

Medication and Psychiatric Acute Care Units

• A study from Hungary in 2008 showed that medication can improve symptoms but does not account for the main difference between patients.

• Psychiatrists are hesitant to refer patients for studies involving dark-adapted testing due to concerns about patient well-being.

• Studies have been done using light-adaptive testing instead of dark-adaptive testing for acutely psychotic patients.

• It is important to be cautious when conducting research with acutely psychotic patients, as their reactions may be unpredictable.

Longitudinal Studies and ERG Testing

The potential applications of ERG testing in longitudinal studies are discussed, including predicting impending relapse earlier than symptom onset. However, while ERG testing has shown good separation between patients and controls, it may not be reliable enough to diagnose schizophrenia alone.

Longitudinal Studies and ERG Testing

• Longitudinal studies using ERG testing could potentially predict impending relapse earlier than symptom onset.

• While ERG testing has shown good separation between patients and controls, it may not be reliable enough to diagnose schizophrenia alone.

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Be Sure

In this section, the speaker says "be sure" and receives applause from the audience.

• The speaker says "be sure".

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