Visual Evoked Potentials (VEPs) are evoked potentials generated in response to visual stimuli. The flash VEP (FVEP) is used less frequently than pattern-reversal VEP (PR-VEP) because; it shows great variations in both latency and amplitude in normal subjects. The advantage of FVEP is its feasibility in non-cooperative subjects, which circumvents the major limitation of PR-VEP. The present study...

It is generally assumed that there is no sizable proportion of motion detectors in the primate retina. To test this specifically for humans, visual evoked potentials (VEPs) and electroretinograms (ERGs) were recorded simultaneously to visual motion onset (9.3 degrees /s) of an expanding or contracting 'dartboard'. The degree of motion-specific responses in cortex and retina was assessed by test...

We congratulate Dr. Azarmina and colleagues on their study investigating the latency of visual evoked potentials (VEPs) among healthy females during and after menstruation.1 The authors found significantly increased latencies in pattern and flash VEP in their subjects. Their findings are particularly remarkable since the mean latency of the P100 wave was increased by approximately 20 ms (mean i...

Background. Patients with diabetes suffer central nervous system (CNS) damage which is difficult to diagnose. Examination of evoked potentials (EP) — bioelectric responses of the nervous system to external sensory (SEP), acoustic (BAEP) or visual (VEP) stimuli — may be used to assess CNS dysfunction. Material and methods. We performed VEP and SEP studies in the median (SEPm) and the tibial (SEP...

Back ground: Caffeine a white crystalline xanthine alkaloid is the most widely used psychoactive stimulant in the world. Inspite of being used as a substance of abuse, it is widely used as a CNS and metabolic stimulant for its short term and long term pharmacological action. A number of studies with dramatic results have proved that caffeine is a stimulant. Review of literature: Effects of caff...

PURPOSE To evaluate the latency of visual evoked potentials (VEPs) in healthy women during and after menstruation. METHODS Pattern and flash VEPs were performed in 15 healthy women aged 18 to 25 years on the maximum bleeding day (luteal phase) and 7 days after the menstrual cycle (follicular phase). RESULTS Mean latency was 119.6 msec on the maximum bleeding day and 100.8 msec one week afte...

When geometric or contoured shapes are generated as disparity regions in dynamic random-dot stereograms, the question of whether the subject's response is evoked largely by boundaries and corners of the disparate region arises. To examine this question a disparate square was shifted randomly within a focal region at one millisecond intervals, resulting in a nebulous stimulus which "welled up" i...

The objective of this study is development of driver's sleepiness using Visually Evoked Potentials (VEP). VEP computed from EEG signals from the visual cortex. We use the Steady State VEPs (SSVEPs) that are one of the most important EEG signals used in human computer interface systems. SSVEP is a response to visual stimuli presented. We present a classification method to discriminate between cl...

purpose: comparison of the results of visual evoked potential (vep) in time domain and frequency domain between multiple sclerosis (ms) suspected patients and normal indivisuals. method: eleven ms suspected patients with normal visual findings and 20 normal individuals were tested by vep. results were compared between two groups. results: the time domain results showed no significant difference...