Multi-resolution dyadic wavelet denoising approach for extraction of visual evoked potentials in the brain

2004 ◽  
Vol 151 (3) ◽  
pp. 180 ◽  
Author(s):  
J.-H. Zhang ◽  
K. Janschek ◽  
J.F. Böhme ◽  
Y.-J. Zeng
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Wavelet Denoising ◽  
Dyadic Wavelet ◽  
The Brain ◽  
Visual Evoked

scholarly journals Exploring the dynamic mechanisms of steady-state visual evoked potentials at the whole-brain level: evidence from a computational study

2021 ◽  
Author(s):  
Ge Zhang ◽  
Yan Cui ◽  
Yangsong Zhang ◽  
Hefei Cao ◽  
Guanyu Zhou ◽  
...  
Keyword(s):  
Steady State ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Large Scale ◽  
Whole Brain ◽  
Frequency Sensitivity ◽  
Dynamic Mechanisms ◽  
Brain Level ◽  
The Brain ◽  
Visual Evoked

AbstractPeriodic visual stimulation can induce stable steady-state visual evoked potentials (SSVEPs) distributed in multiple brain regions and has potential applications in both neural engineering and cognitive neuroscience. However, the underlying dynamic mechanisms of SSVEPs at the whole-brain level are still not completely understood. Here, we addressed this issue by simulating the rich dynamics of SSVEPs with a large-scale brain model designed with constraints of neuroimaging data acquired from the human brain. By eliciting activity of the occipital areas using an external periodic stimulus, our model was capable of replicating both the spatial distributions and response features of SSVEPs that were observed in experiments. In particular, we confirmed that alpha-band (8-12 Hz) stimulation could evoke stronger SSVEP responses; this frequency sensitivity was due to nonlinear resonance and could be modulated by endogenous factors in the brain. Interestingly, the stimulus-evoked brain networks also exhibited significant superiority in topological properties near this frequency-sensitivity range, and stronger SSVEP responses were demonstrated to be supported by more efficient functional connectivity at the neural activity level. These findings not only provide insights into the mechanistic understanding of SSVEPs at the whole-brain level but also indicate a bright future for large-scale brain modeling in characterizing the complicated dynamics and functions of the brain.

Search for Correlations Between Genotypes and Electrophysiological Patterns in Migraine: The MTHFR C677T Polymorphism and Visual Evoked Potentials

Cephalalgia ◽  
2007 ◽  
Vol 27 (10) ◽  
pp. 1142-1149 ◽  
Author(s):  
D Magis ◽  
M Allena ◽  
G Coppola ◽  
L Di Clemente ◽  
P Gérard ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Methylenetetrahydrofolate Reductase ◽  
Mthfr C677t ◽  
Pattern Reversal ◽  
C677t Polymorphism ◽  
Mthfr C677t Polymorphism ◽  
Grand Average ◽  
The Brain ◽  
Visual Evoked

Interictally, migraineurs have on average a reduction in habituation of pattern-reversal visual evoked potentials (PR-VEP) and in mitochondrial energy reserve. 5,10-Methylenetetrahydrofolate reductase (MTHFR) is involved in folate metabolism and its C677T polymorphism may be more prevalent in migraine. The aim of this study was to search in migraineurs for a correlation between the MTHFR C677T polymorphism and the PR-VEP profile. PR-VEP were recorded in 52 genotyped migraine patients: 40 female, 24 without (MoA), 28 with aura (MA). Among them 21 had a normal genotype (CC), 18 were heterozygous (CT) and 13 homozygous (TT) for the MTHFR C677T polymorphism. Mean PR-VEP N1-P1 amplitude was significantly lower in CT compared with CC, and tended to be lower in TT with increasing age. The habituation deficit was significantly greater in CC compared with TT subjects. The correlation between the cortical preactivation level, as reflected by the VEP amplitude in the first block of averages, and habituation was stronger in CC than in CT or TT. The MTHFR C677T polymorphism could thus have an ambiguous role in migraine. On one hand, the better VEP habituation which is associated with its homozygosity, and possibly mediated by homocysteine derivatives increasing serotoninergic transmission, may protect the brain against overstimulation. On the other hand, MTHFR C677T homozygosity is linked to a reduction of grand average VEP amplitude with illness duration, which has been attributed to brain damage.

scholarly journals Effect of mechanical tactile noise on amplitude of visual evoked potentials: multisensory stochastic resonance

2015 ◽  
Vol 114 (4) ◽  
pp. 2132-2143 ◽  
Author(s):  
Ignacio Méndez-Balbuena ◽  
Nayeli Huidobro ◽  
Mayte Silva ◽  
Amira Flores ◽  
Carlos Trenado ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Stochastic Resonance ◽  
Visual Evoked Potentials ◽  
Gaussian Noise ◽  
Index Finger ◽  
Sensory Modality ◽  
Visual Pathway ◽  
Input Noise ◽  
The Brain ◽  
Visual Evoked

The present investigation documents the electrophysiological occurrence of multisensory stochastic resonance in the human visual pathway elicited by tactile noise. We define multisensory stochastic resonance of brain evoked potentials as the phenomenon in which an intermediate level of input noise of one sensory modality enhances the brain evoked response of another sensory modality. Here we examined this phenomenon in visual evoked potentials (VEPs) modulated by the addition of tactile noise. Specifically, we examined whether a particular level of mechanical Gaussian noise applied to the index finger can improve the amplitude of the VEP. We compared the amplitude of the positive P100 VEP component between zero noise (ZN), optimal noise (ON), and high mechanical noise (HN). The data disclosed an inverted U-like graph for all the subjects, thus demonstrating the occurrence of a multisensory stochastic resonance in the P100 VEP.

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