The term visually evoked potential (VEP) refer to electrical potentials, initiated by brief visual stimuli, which are recorded from the scalp overlying visual cortex, VEP waveforms are extracted from the electro-encephalogram (EEG) by signal averaging. VEPs are used primarily to measure the functional integrity of the visual pathways from retina via the optic nerves to the visual cortex of the ...

The recent developments of new devices and advances in anesthesiology have greatly improved the utility and accuracy of intraoperative neurophysiological monitoring (IOM). Herein, we review the basic principles of the electrophysiological methods employed under IOM in the operating room. These include motor evoked potentials, somatosensory evoked potentials, electroencephalography, electromyogr...

There is an ongoing controversy regarding the role of gender in modulating components of the human visual-evoked potential (VEP) and event-related potentials (ERPs). Our aim was to further characterize the role of gender on VEPs, ERPs and response performance in an object recognition task. We recorded VEPs and reaction time (RT) in a paradigm wherein subjects responded to a randomly presented "...

The study aimed at testing, by a visual evoked potential method, the hypothesis of the hemispheric specialization in processing of high and low-spatial frequencies. Twenty four right-handed subjects (12 males and 12 females) were presented with square-wave vertical gratings of various spatial frequencies (0.67, 0.86, 1.20, 2.00, 2.40, 3.00, 3.30, 6.00 and 7.50 c/deg). Gratings were presented in...

This paper investigates controlling humanoid robot behavior via motion-onset specific N200 potentials. In this study, N200 potentials are induced by moving a blue bar through robot images intuitively representing robot behaviors to be controlled with mind. We present the individual impact of each subject on N200 potentials and discuss how to deal with individuality to obtain a high accuracy. Th...

Motion contrast contributes to the segregation of a two-dimensional figure from its background, yet many questions remain about its neural mechanisms. We measured steady-state visual evoked potential (SSVEP) responses to moving dot displays in which figure regions emerged from and disappeared into the background at a specific temporal frequency (1.2Hz, F1), based on regional differences of dot ...

Visually-evoked potentials (VEPs) were recorded from infants between the ages of 2 and 11 months in response to 2.5 c/deg main axis and oblique square wave gratings. The oblique effect first appears at 3 months of age; some infants showed smaller VEP amplitude and/or longer VEP latency for obliquely oriented gratings. Regarding the age of onset of the oblique effect, VEP data from this study ag...

Hyperacuity thresholds of a few arc seconds can be achieved psychophysically for a variety of spatial localization tasks. The present experiments show that evoked potentials can be elicited in response to the introduction of vernier offsets, but not by the introduction of other cues to hyperacuity such as bisection or relative pattern motion, although each of these cues is equally salient psych...

Several studies provided evidence that the amplitudes of laser-evoked potentials (LEPs) are modulated by attention. However, previous reports were based on across-trial averaging of LEP responses at the expense of losing information about intertrial variability related to attentional modulation. The aim of this study was to investigate the effects of somatosensory spatial attention on single-tr...

Somatosensory, visual and brainstem auditory evoked potentials were recorded in 10 unpremedicated patients anaesthetized with isoflurane in oxygen. Recordings were made at 0.5%, 1.1% and 1.65% (six patients) end-tidal isoflurane concentration. There were statistically significant increases in the latencies of the somatosensory (N20), visual and brainstem auditory potentials (waves III and V) wi...