PURPOSE The visual evoked potential (VEP) is a frequently used noninvasive measurement of visual function. However, high-amplitude variability has limited its potential for evaluating axonal damage in both laboratory and clinical research. This study was conducted to improve the reliability of VEP amplitude measurement in rats by using electroencephalogram (EEG)-based signal correction. METHO...

Dynamic random dot correlograms (DRDCs) are binocular stimuli that evoke a percept and a visual evoked potential (VEP) only in case of a mature and functional binocular system. DRDC-VEP is a method extensively used to study cortical binocularity in human infants and nonverbal children. Although the DRDC-VEP was invented 3 decades ago, neither the fundamental parameters, including contrast, of t...

The visual evoked potential (VEP) generated by the amblyopic visual system demonstrates reduced amplitude, prolonged latency, and increased variation in response timing (phase-misalignment). This study examined VEPs before and after occlusion therapy (OT) and whether phase-misalignment can account for the amblyopic VEP deficits. VEPs were recorded to 0.5-4cycles/degree gratings in 10 amblyopic ...

Single visual evoked potentials (VEP) are very weak and noisy signals. For this reason, powerful extraction tools are needed to improve their clinical use. In this paper, we present two methods for filtering VEP: a linear one, based on the adaptive noise canceller scheme where the input signals represent successive recorded VEP, and a new non-linear method which exploits the neural network prop...

The present study compares behaviour-dependent and physostigmine-induced changes of the visual evoked potential (VEP) in unrestrained rats to provide further indications on the role of acetylcholine in the behavioural VEP modulation. On 30 rats the VEPs on the pial surface of the primary visual cortex were investigated during five spontaneous behavioural states. Physostigmine, carbachol and nic...

Cardiac pulse-related artifacts in the EEG recorded simultaneously with fMRI are complex and highly variable. Their effective removal is an unsolved problem. Our aim is to develop an adaptive removal algorithm based on the matching pursuit (MP) technique and to compare it to established methods using a visual evoked potential (VEP). We recorded the VEP inside the static magnetic field of an MR ...

Introduction Retinal input processing in the human visual system involves a phasic and tonic neural response. We investigated the role of the magno- and parvocellular systems by comparing the influence of the active neural population size and its discharge activity on the amplitude and latency of four VEP components. Method We recorded the scalp electric potential of 20 human volunteers viewi...

Between attacks, migraine patients are characterized by potentiation instead of habituation of stimulation-evoked cortical responses. It is debated whether this is due to increased or decreased cortical excitability. We have studied the changes in visual cortex excitability by recording pattern-reversal visual evoked potentials (PR-VEP) after low- and high-frequency repetitive transcranial magn...

Neurology 2012;79:732–733 For 40 years, visual evoked cortical potentials (VEPs) have been used to aid in the diagnosis of demyelinating optic neuropathy.1 Early studies demonstrated an increased latency of the positive peak normally seen at about 100 msec—the P100—in patients with optic neuritis.1 Since the P100 often remains prolonged following recovery from the acute episode, the VEP is usef...