scholarly journals Differences in Early and Late Pattern-Onset Visual-Evoked Potentials between Self-Reported Migraineurs and Controls

2019 ◽  
Author(s):  
Chun Yuen Fong ◽  
Wai Him Crystal Law ◽  
Jason Braithwaite ◽  
Ali Mazaheri
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Visual Processing ◽  
Aversive Stimulus ◽  
Feedback Mechanism ◽  
Similar Response ◽  
Response Patterns ◽  
Spatial Frequencies ◽  
Late Negativity ◽  
Visual Evoked

AbstractStriped patterns have been shown to induce strong visual illusions and discomforts to migraineurs in the literature. Previous research has suggested that those unusual visual symptoms be linked with the hyperactivity on the visual cortex of migraine sufferers. The present study searched for evidence supporting this hypothesis by comparing the visual evoked potentials (VEPs) elicited by striped patterns of specific spatial frequencies (0.5, 3, and 13 cycles) between a group of 29 migraineurs (17 with aura/12 without) and 31 non-migraineurs. In addition, VEPs to the same stripped patterns were compared between non-migraineurs who were classified as hyperexcitable versus non-hyperexcitable using a previously established behavioural pattern glare task. We found that the migraineurs had a significantly increased N2 amplitude for stimuli with 13 cpd gratings but an attenuated late negativity (LN: 400 – 500 ms after the stimuli onset) for all the spatial frequencies. Interestingly, non-migraineurs who scored as hyperexcitable appeared to have similar response patterns. We proposed that the enhanced N2 could reflect disruption of the balance between parvocellular and magnocellular pathway, which is in support of a grating-induced cortical hyperexcitation mechanism on migraineurs. On the other hand, the attenuation of the late negativity could reflect a top-down feedback mechanism to suppress visual processing of an aversive stimulus.

Visual Evoked Potentials and Electroretinograms

2017 ◽  
Author(s):  
Gastone G. Celesia ◽  
Neal S. Peachey
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Visual Processing ◽  
Objective Assessment ◽  
Clinical Signs ◽  
Simultaneous Recording ◽  
Pattern Erg ◽  
Pattern Vep ◽  
Toxicity Of Drugs ◽  
Visual Evoked

Electrophysiological testing of vision permits the objective assessment of the function of the retina, visual pathways, and cortices. This chapter covers visual evoked potentials (VEPs) and electroretinography (ERG). Flash ERG is useful in evaluating the outer retinal function and specifically helping in the diagnosis of retinal degeneration, monitoring the progress of retinal diseases, monitoring the retinal toxicity of drugs, and understanding the pathophysiology of retinal disorders. VEPs to various stimuli are useful in evaluating macular disorders, diagnosing optic neuropathies, detecting silent pathologies in the absence of other clinical signs of visual impairment, and evaluating disturbances of visual processing in degenerative diseases of the central nervous system. Simultaneous recording of pattern ERG and pattern VEP permits the differentiation between maculopathies and optic neuropathy.

scholarly journals A Comprehensive Review on Methodologies Employed for Visual Evoked Potentials

Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Ruchi Kothari ◽  
Pradeep Bokariya ◽  
Smita Singh ◽  
Ramji Singh
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Visual Processing ◽  
Visual Information ◽  
Extrastriate Cortex ◽  
Historical Aspect ◽  
Clinical Disorders ◽  
Bioelectric Signals ◽  
Visual Evoked

Visual information is fundamental to how we appreciate our environment and interact with others. The visual evoked potential (VEP) is among those evoked potentials that are the bioelectric signals generated in the striate and extrastriate cortex when the retina is stimulated with light which can be recorded from the scalp electrodes. In the current paper, we provide an overview of the various modalities, techniques, and methodologies which have been employed for visual evoked potentials over the years. In the first part of the paper, we cast a cursory glance on the historical aspect of evoked potentials. Then the growing clinical significance and advantages of VEPs in clinical disorders have been briefly described, followed by the discussion on the earlier and currently available methods for VEPs based on the studies in the past and recent times. Next, we mention the standards and protocols laid down by the authorized agencies. We then summarize the recently developed techniques for VEP. In the concluding section, we lay down prospective research directives related to fundamental and applied aspects of VEPs as well as offering perspectives for further research to stimulate inquiry into the role of visual evoked potentials in visual processing impairment related disorders.

Binocular Advantage and Visual Processing in Dyslexic and Control Children as Measured by Visual Evoked Potentials

1990 ◽  
Vol 67 (2) ◽  
pp. 105-110 ◽  
Author(s):  
HAROLD A. SOLAN ◽  
VESNA G. SUTIJA ◽  
ANTHONY P. FICARRA ◽  
STEPHEN A. WURST
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Visual Processing ◽  
And Control ◽  
Visual Evoked

scholarly journals Neuronal Generators of Visual Evoked Potentials in Humans: Visual Processing in the Human Cortex

Epilepsia ◽  
1997 ◽  
Vol 38 (5) ◽  
pp. 600-610 ◽  
Author(s):  
Santiago Arroyo ◽  
Ronald P. Lesser ◽  
Wai-Tat Poon ◽  
W. Robert ◽  
S. Webber ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Visual Processing ◽  
Human Cortex ◽  
Evoked Potentials In Humans ◽  
Visual Evoked

Sunlight irradiance and habituation of visual evoked potentials in migraine: The environment makes its mark

Cephalalgia ◽  
2017 ◽  
Vol 38 (7) ◽  
pp. 1351-1360 ◽  
Author(s):  
Marco Lisicki ◽  
Kevin D’Ostilio ◽  
Michel Erpicum ◽  
Jean Schoenen ◽  
Delphine Magis
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Visual Processing ◽  
Episodic Migraine ◽  
Adaptive Behaviour ◽  
Inclusion Criteria ◽  
Functional Changes ◽  
Prospective Trials ◽  
The Difference ◽  
Visual Evoked

Background Migraine is a complex multifactorial disease that arises from the interaction between a genetic predisposition and an enabling environment. Habituation is considered as a fundamental adaptive behaviour of the nervous system that is often impaired in migraine populations. Given that migraineurs are hypersensitive to light, and that light deprivation is able to induce functional changes in the visual cortex recognizable through visual evoked potentials habituation testing, we hypothesized that regional sunlight irradiance levels could influence the results of visual evoked potentials habituation studies performed in different locations worldwide. Methods We searched the literature for visual evoked potentials habituation studies comparing healthy volunteers and episodic migraine patients and correlated their results with levels of local solar radiation. Results After reviewing the literature, 26 studies involving 1291 participants matched our inclusion criteria. Deficient visual evoked potentials habituation in episodic migraine patients was reported in 19 studies. Mean yearly sunlight irradiance was significantly higher in locations of studies reporting deficient habituation. Correlation analyses suggested that visual evoked potentials habituation decreases with increasing sunlight irradiance in migraine without aura patients. Conclusion Results from this hypothesis generating analysis suggest that variations in sunlight irradiance may induce adaptive modifications in visual processing systems that could be reflected in visual evoked potentials habituation, and thus partially account for the difference in results between studies performed in geographically distant centers. Other causal factors such as genetic differences could also play a role, and therefore well-designed prospective trials are warranted.

scholarly journals Top–Down Attention Is Limited Within but Not Between Feature Dimensions

2019 ◽  
Vol 31 (8) ◽  
pp. 1173-1183 ◽  
Author(s):  
Nika Adamian ◽  
Elena Slaustaite ◽  
Søren K. Andersen
Keyword(s):  
Steady State ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Visual Processing ◽  
Attentional Selection ◽  
Target Color ◽  
Attention Condition ◽  
Top Down ◽  
Feature Based ◽  
Visual Evoked

In natural vision, processing of spatial and nonspatial features occurs simultaneously; however, the two types of attention in charge of facilitating this processing have distinct mechanisms. Here, we tested the independence of spatial and feature-based attention at different stages of visual processing by examining color-based attentional selection while spatial attention was focused or divided. Human observers attended to one or two of four fields of randomly moving dots presented in both left and right visual hemifields. In the focused attention condition, the target stimulus was defined both by color and location, whereas in the divided attention condition stimuli of the target color had to be attended in both hemifields. Sustained attentional selection was measured by means of steady-state visual evoked potentials elicited by each of the frequency-tagged flickering dot fields. Additionally, target and distractor selection was assessed with ERPs to these stimuli. We found that spatial and color-based attention independently modulated the amplitude of steady-state visual evoked potentials, confirming independent top–down influences on early visual areas. In contrast, P3 amplitudes elicited only by targets and distractors of the attended color were subject to space-based enhancement, suggesting increasing integration of spatial and feature-based selection over the course of perceptual processing.

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