Publications by authors named "Evelyn B N Friedel"

Background: Electroretinograms (ERG) are usually recorded with non-invasive corneal electrodes, requiring direct contact with the ocular surface. However, corneal electrode application is not tolerated by some individuals. The advent of handheld ERG devices has facilitated the use of skin electrodes for ERG measurements.

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Article Synopsis
  • Previous electroretinogram studies show that people with major depressive disorder (MDD) have reduced retinal contrast gain, affecting their visual perception.
  • The study compares contrast suppression in 21 MDD patients and 23 healthy controls (HC) using various stimuli and finds that MDD patients demonstrate less contrast suppression, especially with high stimulus contrast.
  • These findings suggest that altered dopamine function and changes in retinal processing may contribute to the visual perception issues observed in individuals with MDD.
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Article Synopsis
  • - The study investigates how depression affects visual processing using the electroretinogram (ERG), focusing on patients with major depressive disorder (MDD) and comparing them to healthy controls (HC).
  • - Results showed that MDD patients had lower contrast sensitivity and reduced pattern ERG (PERG) ratios, indicating alterations in visual processing linked to depression.
  • - The use of a handheld ERG device revealed diminished a-wave amplitudes in MDD patients, highlighting its potential as a practical tool for depression research and suggesting the PERG may serve as an objective marker for the condition.
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Purpose: The steady-state pattern electroretinogram (ssPERG) is used to assess retinal ganglion cell function in a variety of research contexts and diagnostic applications. In certain groups of patients or study participants, stable central fixation of the stimulus is not guaranteed. The present study aimed at assessing the effects of misfixation on the ssPERG response to checkerboard reversal stimuli.

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Since the retina shares its embryological origin with the central nervous system, optical coherence tomography (OCT), an imaging technique frequently employed in ophthalmology to analyze the macula and intraretinal layer thicknesses and volumes, has recently become increasingly important in psychiatric research. We examined 34 autistic and 31 neurotypical adults (NT) using OCT. Autistic adults had reduced overall macular and outer nuclear layer (ONL) thickness and volume compared to NT.

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The electroretinogram (ERG) allows the investigation of retinal signaling pathways and has increasingly been applied in individuals with mental disorders in search for potential biomarkers of neurodevelopmental disorders. Preceding ERG examinations in individuals with autism spectrum disorders (ASD) showed inconsistent results, which might be due to the small number of participants, heterogeneity of the ASD population, differences in age ranges, and stimulation methods. The aim of this study was to investigate functional retinal responses in adults with ASD by means of the light-adapted (photopic) ERG.

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Ophthalmological methods have increasingly raised the interest of neuropsychiatric specialists. While the integrity of the retinal cell functions can be evaluated with the electroretinogram (ERG), optical coherence tomography (OCT) allows a structural investigation of retinal layer thicknesses. Previous studies indicate possible functional and structural retinal alterations in patients with schizophrenia.

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The retina has gained increasing attention in non-ophthalmological research in recent years. The pattern electroretinogram (PERG), a method to evaluate retinal ganglion cell function, has been used to identify objective correlates of the essentially subjective state of depression. A reduction in the PERG contrast gain was demonstrated in patients with depression compared to healthy controls with normalization after remission.

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Are alternation and co-occurrence of stimuli of different sensory modalities conspicuous? In a novel audio-visual oddball paradigm, the P300 was used as an index of the allocation of attention to investigate stimulus- and task-related interactions between modalities. Specifically, we assessed effects of modality alternation and the salience of conjunct oddball stimuli that were defined by the co-occurrence of both modalities. We presented (a) crossmodal audio-visual oddball sequences, where both oddballs and standards were unimodal, but of a different modality (i.

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