... Accession Number : AD0624103. Title : THE VISUALLY EVOKED POTENTIALS RECORDED TRANSCRANIALLY IN NORMAL MAN. ...
DTIC Science & Technology
Abnormalities in visually evoked responses have been used to demonstrate abnormal optic nerve fibre projections in human albinos, who have anomalous nystagmoid movements. Using visually evoked potentials we tested the hypothesis that patients with ...
PubMed Central
Language: English ...
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... Accession Number : ADA178904. Title : Visual Evoked Potentials to Luminance and Chromatic Contrast in Rhesus Monkeys,. ...
... Title : Frequency Analysis of Visual Evoked Potentials from Anesthetized 'Macaca nemestrina' using Power Spectra Estimates. ...
... Accession Number : ADA240097. Title : Auditory and Visual Evoked Potentials as a Function of Sleep Deprivation and Irregular Sleep. ...
... Accession Number : ADA228488. Title : Auditory and Visual Evoked Potentials as a Function of Sleep Deprivation and Irregular Sleep. ...
... Accession Number : ADA042619. Title : Examination of Auditory Attention and Visual Evoked Potentials. Descriptive Note : Final rept.,. ...
Visual illusions characterized by distortion of form, size, reciprocal position of objects, movement, or color, labeled as "Alice in Wonderland" syndrome, were discussed in children with infectious mononucleosis, as well as in other clinical conditions, such as migraine, epilepsy, use of certain hallucinogenic drugs, etc. The purpose of our study was to investigate for the first time ...
PubMed
... 61102F 2313 A5 1I. TITLE (Include Security Classification) VISUAL EVOKED POTENTIALS (U) 12. PERSONAL AUTHOR(S) Nakayama, K. 13a. ...
... Accession Number : ADA187942. Title : Visual Evoked Potentials. Descriptive Note : Annual technical rept. 1 Sep 86-31 Aug 87,. ...
... Accession Number : ADA155912. Title : Matched Filtering of Visual Evoked Potentials to Detect Acceleration (+Gz) INduced Blackout. ...
Page 1. MULTIPLE COLOR STIMULUS INDUCED STEADY STATE VISUAL EVOKED POTENTIALS M. Cheng, X. Gao, S ...
... Accession Number : ADA411770. Title : Multiple Color Stimulus Induced Steady State Visual Evoked Potentials. Corporate ...
... Accession Number : ADA145508. Title : Foveal Xenon Flash Disruption of Steady-State Visual Evoked Potentials,. Corporate ...
Visual evoked potentials (VEPs) were elicited from 29 patients who had experienced a previous attack of acute primary angle closure glaucoma. The VEPs were shown to be abnormal in at least one of the measures (latency, amplitude, contrast threshold, or slope) in 72.4% of affected eyes, whereas only 41.4% indicated ...
... potentials. The visual evoked potential (VEP) complex and motor evoked potentials (MEPs) have been of particular interest. ...
Alterations were monitored of somatosensory evoked potentials in children with bilateral spastic cerebral palsy and these findings correlated with relevant clinical and laboratory parameters. Fifty-one children with bilateral spastic cerebral palsy (31 boys, 20 girls; age range 24-168 months) participated in the study. Abnormal somatosensory evoked ...
Aim:? Previous studies have shown visual evoked potential (VEP) abnormalities in infants and animals born small for gestational age (SGA) compared with controls. The current exploratory study aims to investigate whether VEP abnormalities persist in older ages. Methods:? Pattern VEP latencies ...
Background and PurposeGuillain-Barr� syndrome (GBS) is an acute demyelinating polyneuropathy with various clinical features. Optic neuritis occurs in rare cases. In this study we determined the incidence and patterns of visual evoked potential (VEP) abnormality in GBS in association with ophthalmologic ...
... The first study was concerned with visual evoked potentials (VEPs) and detection performance under conditions of four-digit overprinting. ...
The effect of task relevance on P3 (waveform of human evoked potential) waves and the methodologies used to deal with them are outlined. Visual evoked potentials (VEPs) were recorded from normal adult subjects performing in a visual discrimination task. S...
National Technical Information Service (NTIS)
Two experiments investigated a change in the late positive activity (200 to 550 msec) of the visual evoked potential (VEP). This 'P2-effect,' maximal at the occiput, appeared related to cognitive aspects of information processing. Results did not support ...
Relationships were studied in cats between the augmenting/reducing slopes of visual evoked potentials (VEP) and three types of behavioral responses: learning and performance measures in (1) fixed interval (FI), and (2) differential reinforcement of low ra...
One of the major disadvantages of the clinical use of the pattern visual evoked potential (VEP) in humans has been the failure to isolate and understand the significance of its major components. The two most important of these are N1 (a negative peak typi...
A system was designed to permit simultaneous viewing of the ocular fundus of the rhesus monkey (Macaca mulatta), the accurate placement of laser radiation on the retina, and the stimulation of the site to produce a grating visual evoked cortical potential...
The effects of varying intensity and retinal loci on the monkey visual evoked potential (VEP) were determined by frequency analysis. Frequency information in the VEP was investigated by use of the Fast Fourier Transform (FFT), the FFT output being represe...
A comparison between visual evoked potential (VEP) and behavioral measures of flashblindness following exposure to intense but eyesafe xenon flashes was performed. The purpose was to further validate the animal model of laser flashblindness based on VEP r...
Acute exposure to the insecticide/acaricide chlordimeform (CDM) produces large, selective and transient changes in visual evoked potentials of rats. Experiments were conducted investigating the influence of physical characteristics of the evoking stimuli ...
A series of experiments was conducted to assess the comparability of physiological processes in rat and human visual systems. n the first set of experiments, transient visual evoked potentials (VEPs) were elicited by the onset of sine-wave gratings of various spatial frequencies....
EPA Science Inventory
Acute exposure to the insecticide/acaricide chlordimeform (CDM) produces large, selective and transient changes in visual evoked potentials of rats. Experiments were conducted investigating the influence of physical characteristics of the evoking stimuli on the CDM effect. Adult ...
... Regan, D., Visual evoked potentials and visual Naval Submarine Medical Research Laboratory perception in multiple sclerosis, in Proceedings of ...
... Corporate Author : NAVY PERSONNEL RESEARCH AND DEVELOPMENT CENTER SAN ... Visual evoked brain potentials were generated by a ...
... Title : Effects of High Altitude on Neurological and Pulmonary Function: The Effect of High Altitude on Visual Evoked Potentials in Humans on Mt. ...
... FLASHBLINDNESS, ANIMALS, BEHAVIOR, CORRELATION, ESTIMATES, FREQUENCY, GRATINGS(SPECTRA), HEAD(ANATOMY), LASERS ...
Averaged visual evoked potentials are being studied in man and animals by means of a computer of average transients (CAT). Modifications incorporated to this computer are described. Effects of psychotropic drugs upon the averaged visual evoked response (V...
The value of flight of colours (FOC), i.e. the succession of coloured afterimages following light stimulation, in diagnosing and following visual impairment was evaluated in 65 patients with multiple sclerosis (MS). Previous optimistic reports of the use of a pocket flashlight (PFL) method could not be confirmed, and are ascribed to inadequate methods. An electronic flashlight (EFL) method ...
Pattern reversal visual evoked potentials (pVEP) were studied in 39 male rubber factory workers in the age range of 18-55 years and 20 control subjects (aged 18-46 years) not exposed to the rubber factory environment. Results revealed that 20 (51%) rubber factory workers had abnormal latencies of wave P1 (dominant ...
A 27 year old woman with Graves' disease developed progressive ophthalmopathy and was noted to have abnormal visual evoked responses (VER). She was treated with high dose prednisone with clinical improvement and return of the visual evoked responses to normal. On withdrawal of steroids symptoms ...
The primary use of visual evoked potentials (VEPs) has been in clinical applications ... To verify that the evoked potentials were detectable in the EEG , ...
NASA Website
A female infant with horizontal nystagmus and normal ophthalmic examination had isolated absence of the optic chiasm on magnetic resonance imaging. Eye movements were recorded on video and reviewed. Horizontal nystagmus without see-saw nystagmus was observed. Visual evoked potential showed inter-hemispheric asymmetry compatible with ...
Visual evoked responses were obtained in 47 Parkinsonian patients and 26 age-matched controls. The stimulation to binocular and uniocular latency of the major positive peak was longer in the Parkinsonian patients and its amplitude was smaller than in the control subjects. There was a large interocular difference suggesting that at least part of the delay ...
Squirrel monkeys with induced canine distemper virus (CDV) encephalitis showed characteristic clinical signs such as seizures or myoclonus, with EEGs showing periodic synchronized discharge (PSD). Histopathologically, there was gliosis and neuronal degeneration diffusely distributed in both the gray and white matters in the subacute phase, the lesions resembling those found in childhood acute ...
At separate institutions, pattern reversal visual evoked potentials (VEPs) were recorded in children and older patients with phenylketonuria and compared with MRI of the brain. In nine patients aged less than 14 years, who were still on a diet low in phenylalanine, VEPs were clearly abnormal in only one and the ...
Coherent motion responses of patients with mild to moderate strabismic amblyopia were compared to those of normals using visual-evoked potentials (VEPs). Responses were elicited by dynamic random-dot kinematograms that alternated at 0.83 Hz between globally coherent (left-right) and incoherent (random) motion states. Tuning curves were measured at the ...
The manifestations of bilirubin encephalopathy include disturbances in the visual pathway (visual gaze paralysis and distorted visual perception). In the young jaundiced Gunn rat (jj) model of hyperbilirubinemia, significant differences in visual evoked potential (VEP) patterns have been recorded during development. In the present ...
We describe three patients with central areolar choroidal dystrophy whose electroretinograms (ERGs) and pattern visually evoked cortical potentials (VECPs) confirmed their macular dysfunction. Visual fields measured by Goldmann perimetry showed central relative scotomata corresponding to a dystrophic lesion. Dark adaptation curves were ...
Visual-evoked potentials (VEPs) were studied in 55 asymptomatic children with leukemia or solid tumors in remission in order to detect subclinical demyelination of the optic pathway after CNS prophylaxis. In group I (11 patients with ALL studied prospectively), VEP latency was increased in ten after cranial radiation (CR) as compared with previous values. ...
Energy Citations Database
A clinical and neuro-ophthalmological examination using tests of visual acuity, quantitative visual field analysis, tests of colour discrimination, ophthalmoscopy, and pattern visual evoked responses was performed on 2 symptomatic and 16 asymptomatic members of a family with Leber's optic neuropathy. The visual ...
... Personal Author(s) : Halliday,Roy ; Callaway,Enoch ; Naylor,Hilary. Report Date : 1983. Pagination or Media Count : 10. ...
... Corporate Author : LANGLEY PORTER NEUROPSYCHIATRIC INST SAN FRANCISCO CALIF. Personal Author(s) : Callaway,Enoch ; Halliday,Roy. ...
... Accession Number : ADA412102. Title : Measurement of Human Color Responses Using Visual Evoked Potential Elicited by Multi-Color Stimulation. ...
... Title : Long Term Effects Retinal Laser Lesions: Multifocal ERGs ( Electroretinogram) and Vernier Visual Evoked Potentials (VEPs). ...
... 79 103 0 3 Page 3. Reports: nlick, DW and Chapman, RM Changes in visually evoked cortical potentials due to methylmercury intoxication. J. Opt. ...
There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field....
... Accession Number : ADP006100. Title : Detection of Acceleration (+Gz) Induced Blackout by Matched-Filtering of Visual Evoked Potentials,. ...
... Brain Mechanisms Underlying Individual ... as visual evoked potential differentially against either a frontal sinus screw or inert neck muscle electrode ...
... 302-469, 507-555 [2] Husar, P., Henning, G., Bispectrum Analysis of Visually Evoked Potentials, IEEE Engineering in Medicine and Biol- ogy 1997 ...
... P300 during sensory conditioning in autistic children ... their usefulness as a predictive tool in evaluating ... Subjects were screened for cigarette smoking ...
We present a group of eight pediatric cancer patients with a spectrum of visual afferent pathway abnormalities. Changes include decreased visual acuity, visual field alterations, abnormal visual evoked potentials, changes in the optic disc and nerve fiber layer of the retina, radiation ...
BackgroundMultifocal visual evoked potentials (mfVEP) measure local response amplitude and latency in the field of visionObjectiveTo compare the sensitivity of mfVEP, Humphrey visual field (HVF) and optical coherence tomography (OCT) in detecting visual abnormality in multiple sclerosis (MS) patients.MethodsMfVEP, ...
A search was undertaken for contributions of sustained and transient visual elements to the rat visual-evoked potential (VEP) using procedures similar to those used in humans (Hudnell et al., in preparation). voked potentials were recorded following either pattern-reversal or pat...
We report a case of an occipital arachnoid cyst in an infant, managed on the basis of changes in visually evoked potentials (VEPs). A significant asymmetry of VEP responses prompted neurosurgical intervention, which improved visual behavior and electrical response to both pattern and flash stimuli. PMID:20045363
Pattern-onset visual evoked potentials were elicited from humans by sinusoidal gratings of 0.5, 1, 2 and 4 cpd (cycles/degree) following adaptation to a blank field or one of the gratings. The wave forms recorded after blank field adaptation showed an ear...
Pattern-onset visual evoked potentials were elicited from humans by sinusoidal gratings of 0.5., 1, 2 and 4 cpd (cycles/degree) following adaptation to a blank field or one of the gratings. The wave forms recorded after blank field adaptation showed an early positive component, P...
Chlordimeform (CDM), a formamidine insecticide and monoamine oxidase (MAO) inhibitor, has recently been shown to produce profound changes in visual evoked potentials of hooded rats (Dyer and Boyes, The Toxicologist, 3: 13, 1983). Two experiments were perf...
The simultaneous presentation of two color stimuli was used to determine whether a practical and rapid method of recording human color responses using visual evoked potentials (VEPs) can be done, Multi-color stimulation which consists of two iso-luminant ...
Chlordimeform (CDM), a formamidine insecticide and monoamine oxidase (MAO) inhibitor, has recently been shown to produce profound changes in visual evoked potentials of hooded rats (Dyer and Boyes, The Toxicologist, 3: 13, 1983). Two experiments were performed to determine if the...
Investigations of amitraz neurotoxicity in rats. II. Effects on visual evoked potentials. Boyes, W.K. and Moser, V.C. (1986) Fundam. Appl. Toxicol. 00,000-000. As a part of a series of studies investigating the possible neurotoxicity of amitraz (AMZ), a formamidine pesticide, vis...
Dichoptic stimuli (coincident midpoints and 20 msec interflash interval) of varying temporal relationships were presented to human subjects. Frequency, and subsequent discriminant analysis of the recorded visual evoked potential (VEP), support several obs...
The study attempted to determine whether, as has been suggested, diving can cause demyelined lesions in the optic nerve. Visual evoked potentials were recorded in 20 student divers and 20 experienced divers, and results were compared to two age-matched co...
Electrical stimulation of the digital nerves of the index finger produces changes in the EMG signal during steady voluntary contraction of the first dorsal interosseous muscle. This electrocutaneous reflex (ECR) was studied in 90 patients classified into different categories according to diagnostic criteria for multiple sclerosis. In addition, pattern reversal visual ...
Steady-state visual evoked potential (VEP) responses to counterphased checkerboard stimuli were evaluated in 4 adult male Rhesus monkeys under pentobarbital anesthesia. VEPS were digitized and averaged over 2 sec epochs for 3 consecutive 30 secs during ea...
In vitro studies have demonstrated that toluene disrupts the function of NMDA-glutamate receptors, as well as other channels. This has led to the hypothesis that effects on NMDA receptor function may contribute to toluene neurotoxicity, CNS depression, and altered visual evoked ...
AIM: To assess foveal cone photoreceptor function in patients with unexplained loss of central visual acuity. METHODS: Testing of foveal cone photoreceptor function was performed using scanning laser densitometry, colour matching (Rayleigh equation), and pattern electroretinography (ERG). Standard tests included full field ERG, electrooculography, visual ...
Thirty cases of Minamata disease caused by methyl mercury poisoning with the lesion mainly at the occipital cortex were selected and their spatial contrast sensitivity of vision was examined by the Arden grating chart. At the same time their visual acuity, visual field, and visual evoked cortical potential (VECP) were also ...
SummaryIn mammals, increased GABA in the central nervous system has been associated with abnormalities of visual evoked potentials (VEPs), predominantly manifested as increased latency of the major positive component P100. Accordingly, we hypothesized that patients with a defect in GABA metabolism, succinate ...
Spinocerebellar ataxia 7 (SCA7) is a rare disease, and only few SCA7 families have been reported, especially from East Asia. Clinical features of a genetically confirmed SCA7 Chinese family were evaluated. The onset of the disease varied from 4 years to 48 years, and the initial presenting feature was cerebellar ataxia or visual impairment, or both. There were abnormal ...
We examined the evoked potentials in 2 patients, a 6-month-old girl and a 3-year-old boy, with congenital insensitivity to pain with anhidrosis (CIPA). While auditory brainstem response (ABR) in both patients showed normal latencies, flash visual evoked potential (FVEP) revealed delayed latency of wave IV (P100), ...
PurposeTo evaluate the use of AccuMap multifocal visual evoked potentials (mfVEP) in visual dysfunction caused by macular diseases.MethodsForty-eight eyes with known macular diseases underwent AccuMap mfVEP and microperimetry 1 (MP1) assessments. Evaluation of mfVEP abnormality was based on an amplitude deviation ...
A sequential blanking paradigm was used to determine the effects of more intense, later appearing, stimuli upon the visual evoked potential (VEP) to earlier appearing stimuli. In sequential blanking the presentation of a sequence of visual stimuli at cert...
The effects of alterations in body temperature on flash and pattern reversal evoked potential (FEPs and PREPs) were examined in hooded rats whose thermoregulatory capacity was compromised with lesions of the preoptic/anterior hypothalamic area and/or cold...
This manuscript characterizes the receptor pathways involved in pattern-evoked potential generation in rats " NMDA and nicotinic acetylcholine receptors appear to be involved in the generation of the steady-state pattern evoked response in vivo. " The pattern evok...
A method for recording pattern reversal evoked potentials (PREPs) from awake restrained rats has been developed. The procedure of Onofrj et al. was modified to eliminate the need for anesthetic, thereby avoiding possible interactions of the anesthetic wit...
A method for recording pattern reversal evoked potentials (PREPs) from awake restrained rats has been developed. The procedure of Onofrj et al. was modified to eliminate the need for anesthetic, thereby avoiding possible interactions of the anesthetic with other manipulations of ...
Seventeen unanesthetized monkeys were immobilized and masspotentials (EEG and evoked potentials) before and during flashing light stimulation to atropinized eyes were led by grosselectrodes from the cerebral visual (occipital cortex), association (superio...
Alternative methods of selecting features of visual evoked potentials for automatic pattern classification are compared. Forward sequential feature selection with linear and quadratic discriminant functions, step-wise linear discriminant analysis and exha...
Visually evoked potentials elicited by tachistoscopically displayed alphabetic stimuli were recorded at vertex from six human subjects during a series of item recognition tasks. When presented with a test stimulus, the observer had to decide whether it ha...
The report summarizes the approaches and findings of four experimental studies. The first study was concerned with the nature of the visual evoked potential (VEP) under conditions in which subjects (Ss) made numerosity estimates of rapidly presented small...
The application of auditory and visual evoked potential (VEP) to neurotoxicity testing of humans and animals is reviewed. VEPs elicited by flash, reversing-checkerboard patterns, and sine wave grating are described. The flash evoked potential in rats is altered by exposure to man...
Several studies have indicated a key role for dorsal stream processing in lexical decoding. To examine this relationship further, performance on orthographic and phonological reading tests was compared with both steady-state visual evoked potentials and a putative behavioral measure of dorsal stream processing, coherent motion ...
By recording steady-state visual evoked cortical potentials while intraocular pressure is artificially increased, information can be obtained on the pressure tolerance of the optic nerve head. Such experiments have previously been performed by a vector voltmeter technique. We studied the visual ...
The authors performed neurological, visual evoked potentials (VEP) and electroneurography (ENG) examinations on three groups of workers with occupational exposure to mercury vapors (Hg(0)), and on a control group. The exposure of dental professionals (n = 36) was mild, that of chloralkali plant workers (n = 36) was intermediate, and ...
Visual evoked potential recordings were examined in 45 liver cirrhosis patients with (n = 29) and without (n = 16) encephalopathy, in 15 normal volunteers, and in one patient with an opioid induced stupor state. Visual evoked potential parameters were classified on the ...
Several studies indicate that in cases of psychopathology and alcoholism the amplitude and/or latency of endogenous, scalp-recorded P3 potentials elicited by rare events are abnormal. The P3 complex may normally be a valuable index of the brain's work-load and identification of the neural generator(s) of this late positive component would thus ...
We studied 54 patients with Beh�et's disease, 41 males and 13 females, mean age 28 years. Forty-four patients had auditory brain-stem evoked potential (BAEP) recordings, 39 had pattern reversal visual evoked potentials (VEP), 27 had median nerve somatosensory evoked potential (SEP) ...
Scalp responses evoked by patterned visual stimuli and by changes in luminance were recorded both from human subjects and monkeys. Three models are proposed to explain the observed stimulus-response relations: (1) Luminance deder summing units; (2) a cent...
Progress over the past year has been rapid and wide ranging, covering two primary areas. First, in the area of visual attention, we have shown both the existence of a sustained and a transient component of enhanced pattern recognition. This cannot be expl...
Isoniazid (INH) was given for one year to a group of 28 volunteer civilian aviators. Neurological examinations, mental status examinations, EEG's and visual evoked potentials were monitored at control, six months and twelve months. Minor changes were obse...
Visually evoked brain potentials were recorded from young adult subjects in response to flashed target stimuli that occurred at attended (expected) or unattended spatial locations. Attention was directed to the left or right visual field by a warning cue ...
Subjects with mild Senile Dementia of the Alzheimer Type (SDAT) matched with healthy elderly control subjects were studied longitudinally with clinical assessment, sychometric tests, EEG and visual evoked potentials and computed tomography. The interrelat...
... Personal Author(s) : Schlichting,Christine L. ; Neri,David F. ; Kindness,Scott W. Report Date : 12 JUN 1980. Pagination or Media Count : 13. ...
A series of experiments was performed to determine the parameters necessary to produce immediate measurable changes in the visual system of non human primates after exposure of the fovea to laser radiation. The parameters investigated were stimulus spatia...
The effects of terfenadine, diphenhydramine, and a placebo on flight performance, resting electroencephalographic (EEG) activity, and auditory and visual evoked potential tasks were investigated. Twelve male Army aviators served as subjects in a double-bl...
Administration of high doses of monosodium glutamate (MSG) to rats during the first postnatal week results in severe losses of retinal ganglion cells and interneurons in the retina. The study was conducted to determine what effect this severe retinal dama...
Background illumination has a facilitatory action on the amplitude and total duration of responses of the tactum mesencephali and pallial thickening of the turtle in response to flashes and to electrical stimulation of the optic nerve, analogous to the ph...
The development of electrocortical evoked responses to light flash stimuli was studied in kittens as a function of age, by the use of both cross-sectional and longitudinal methods. Periodic recordings were made in the same kitten over a span of ages rangi...
Acute administration of triethyltin (TET) produces a well-described sequence of pathological events characterized by intramyelinic vacuolation, edema, and histotoxic hypoxia. Recent behavioral studies have attempted to characterize the functional conseque...
These experiments sought to establish a dose-effect relationship between the concentration of perchloroethylene (PCE) in brain tissue and concurrent changes in visual function. A physiologically-based pharmacokinetic (PBPK) model was implemented to predict concentrations of PCE ...
Acute administration of triethyltin (TET) produces a well-described sequence of pathological events characterized by intramyelinic vacuolation, edema, and histotoxic hypoxia. Recent behavioral studies have attempted to characterize the functional consequences of TET exposures. In...
Neurofibromatosis type 1 (NF1) is a common, autosomal dominant neurocutaneous disorder in which any organ system, including the skin, skeleton and nervous system can be affected. In this study, we compared the electrophysiological and magnetic resonance imaging (MRI) findings in patients with NF1. Thirty-nine adolescent and adult patients (23 women and 16 men) diagnosed with NF1 with a mean age of ...
Visual evoked potentials (VEPs) in response to flash stimuli were recorded from occipital and central-scalp electrodes in the chimpanzee and gorilla. The most notable occipital component of the VEP was a surface-positive wave (P90), the latency of which decreased with development. Central scalp responses, apparent only in older ...
Transient visually evoked potentials (VEPs) to sinusoidal gratings over a range of spatial frequencies have been recorded in cases of optic neuritis. The use of the response to pattern onset in addition to the response to pattern reversal extended the range to higher spatial frequencies by up to two octaves. There was an increase in ...
AIMS: To evaluate the visual function of infants with perinatal cerebral infarction in whom the site and size of the lesion has been determined using magnetic resonance imaging (MRI). METHODS: Twelve infants with cerebral infarction on MRI were studied with a battery of tests specifically designed to evaluate visual function in infancy. This included tests: for visual attention (fixation shifts); ...
Purpose:Occult macular dystrophy (OMD) is a hereditary retinal disease characterized by a normal fundus, normal full-field electroretinograms (ERGs), progressive decrease of visual acuity, and abnormal focal macular ERGs. The purpose of this study was to report pattern-reversal visual-evoked potential (pVEPs) findings in OMD ...
BACKGROUND: Although overt involvement of the central nervous system (CNS) in myasthenia gravis (MG) is considered rare, hyperreflexia is a common and yet unexplained finding. Aquaporin 4 (AQP4), the target autoantigen in neuromyelitis optica, is expressed both in the CNS and in the neuromuscular junction. OBJECTIVES: To evaluate the prevalence of even mild CNS involvement in patients with MG and ...
BackgroundThe mechanisms underlying the interictal habituation deficit of cortical visual evoked potentials (VEP) in migraine are not well understood. Abnormal long-term functional plasticity of the visual cortex may play a role and it can be assessed experimentally by light deprivation (LD).MethodsWe have compared ...
The median nerve somatosensory evoked potentials (SEP), pattern reversal visual evoked potentials (VEP), and brain stem auditory evoked potentials (BAEP) were studied in 109 healthy adults and in 88 patients with acute carbon monoxide (CO) poisoning. The upper limits for normal values of peak ...
This pilot study examined the diagnostic role of multifocal visually evoked potentials (mfVEP) in a small number of patients with diabetes. mfVEP, mfERG, and fundus photographs of both eyes of five patients with diabetes, three with nonproliferative diabetic retinopathy (NPDR) and two without NPDR were examined. Thirteen control ...
Fifty-seven insulin dependent (IDDM) and non-insulin dependent (NIDDM) diabetic patients and 25 controls were studied. Patients with history of strokes, hypoglycaemia, hearing impairment, diabetic retinopathy, etc, were excluded. Clinical examination of central nervous system (CNS) and computerised tomography scan of brain were absolutely normal in all cases. Neuroelectrophysiological tests done ...
Normocephalic children found to have ventriculomegaly during evaluation of long-standing (4.5-8.5 years) neurological disorder were tested for academic achievement, intellectual quotient and neuropsychological functioning. Radioactive iodinated serum cisternography, pre and post-shunt electrophysiological studies (visual evoked responses, brainstem ...
... Accession Number : AD0737208. Title : The Visual Evoked Response as a Measure of Nitrogen Narcosis in Navy Divers,. ...
We compared the focal visual evoked potentials obtained in 52 young subjects with normal vision, evoked by means of three alternating black/color checkerboards generated by a trichromic cathode ray tube (dominant wavelength, 514 nm; colorimetric purity, 0.45) and by means of a scanning laser ophthalmoscope (argon laser beam, 514 nm; ...
We describe a liveborn infant with UPD in association with trisomy 15 mosaicism. Third trimester amniocentesis was performed for suspected IUGR. Results revealed 46,XX/47,XX,+15. The infant initially had respiratory distress and fed poorly. Symmetrical growth retardation, craniofacial dysmorphism, excess nuchal folds, a heart murmur, hypermobile joints, minor limb ...
Trans-synaptic degeneration could exacerbate neurodegeneration in multiple sclerosis (MS). We aimed to assess whether anterograde trans-synaptic degeneration could be identified in the primary visual pathway in vivo. Diffusion tensor imaging (DTI) was used to assess the optic radiations in 15 patients with previous optic nerve inflammation and 9 healthy volunteers. A probabilistic atlas of the ...
The purpose was to test parameters of visual evoked potentials (VEPs) and of event-related potentials (ERPs) in deaf subjects to verify visual and cognitive CNS functions in a handicapped group of the population. Three types of visual stimuli (with dominating parvocellular or magnocellular system activation or with ...
A system was designed to permit simultaneous viewing of the ocular fundus of the rhesus monkey (Macaca mulatta), the accurate placement of laser radiation on the retina, and the stimulation of the site to produce a grating visual evoked cortical potential (VECP). A fundus camera was modified to incorporate a grating whose image was ...
Forty-one patients suffering from autosomal dominant cerebellar ataxia type I (ADCA-I) were subjected to a genotype-phenotype correlation analysis using molecular genetic assignment to the spinocerebellar ataxia type 1, 2 or 3 (SCA1, -2 or -3) genetic locus, clinical examination and nerve conduction as well as evoked potential studies. Pyramidal tract signs, pale discs, and ...
This paper investigates the challenging issue of enabling fast brain-computer interaction to construct a mental speller. Exploiting visual evoked potentials as communication carriers, an online paradigm called "imitating-human-natural-reading" is realized. In this online paradigm, single-trial estimation with the intrinsically ...
Functional magnetic resonance imaging (FMRI) and event related potentials (ERPs) are tools that can be used to image brain activity with relatively good spatial and temporal resolution, respectively. Utilizing both of these methods is therefore desirable in neuroimaging studies to explore the spatio-temporal characteristics of brain function. While several studies have ...
Alzheimer�s disease (AD) is one of the most common causes of dementia in the world. Patients with AD frequently complain of vision disturbances that do not manifest as changes in routine ophthalmological examination findings. The main causes of these disturbances are neuropathological changes in the visual cortex, although abnormalities in the retina and optic nerve cannot ...
We investigated changes in multifocal visual evoked potential (mfVEP) responses due to beta-zone parapapillary atrophy (�PPA). Patients with glaucomatous optic neuropathy (GON) with or without standard achromatic perimetry (SAP) abnormalities were referred for mfVEP testing during a 2-year period. Eyes with good ...
Pattern reversal evoked potentials (PREPs), flash evoked potentials (FEPs), optic nerve axonal transport, and body temperature were measured in hooded rats treated with either saline or the formamidine insecticide/acaricide, chlordimeform (CDM). Rats rece...
Pattern reversal evoked potentials (PREPs), flash evoked potentials (FEPs), optic nerve axonal transport, and body temperature were measured in hooded rats treated with either saline or the formamidine insecticide/acaricide, chlordimeform (CDM). Rats receiving CDM had low body te...
Brainstem, middle-latency, and long-latency auditory-evoked potentials and visual-evoked potentials were recorded for 66 individuals (ages 9-19) in the following comparison groups: cultural-familial mentally retarded, organically mentally retarded, and nonretarded. Target stimuli were evaluated more slowly by both groups with mental retardation. ...
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The effects of acute ethanol treatment on flash and pattern reversal visual evoked potentials (FEPs and PREPs, respectively) were examined in three experiments using Long-Evans rats. The relationships of evoked potential parameters with blood ethanol conc...
Because solvents may selectively alter portions of visual evoked potentials, we examined the effects of carbon disulfide (CS2) on flash (FEPs) and pattern reversal (PREPs) evoked potentials. Long-Evans rats were administered (ip) carbon disulfide (CS2) either acutely or for 30 da...
The report describes the consequences of acute exposure to sulfolane upon the visual system, as measured using flash evoked potential (FEPs) and pattern reversal evoked potentials (PREPs). A single injection of either 1/2 or 1/4, but not 1/8 the i.p. LD50 (1600 mg/kg) produced si...
The effects of acute ethanol treatment on flash and pattern reversal visual evoked potentials (FEPs and PREPs, respectively) were examined in three experiments using Long-Evans rats. The relationships of evoked potential parameters with blook ethanol concentration and body temper...
Visual evoked potentials (VEPs) were performed in a blind fashion in 114 children aged 3 to 17 years with different types of headaches, in order to investigate whether this could be helpful in the diagnosis of migraine versus other types of headaches in children. The study showed that the amplitude between P100 and N2 was significantly ...
We propose a new application of the adaptive chirplet transform that involves partitioning signals into non-overlapping sequential segments. From these segments, the local time-frequency structures of the signal are estimated by using a four-parameter chirplet decomposition. Entitled the windowed adaptive chirplet transform (windowed ACT), this approach is applied to the analysis of ...
To establish an electrophysiological marker of binocular vision, visual evoked potentials were recorded in normal observers for whom interocular refraction differences were induced with converging lenses under five dioptre conditions. Patterns of binocular interaction were categorized (facilitation, averaging or suppression) by ...
The electrophysiological characteristics of demyelinated axons are sensitive to changes in plasma calcium concentration. This study investigated the effect of verapamil, a calcium antagonist drug, on brainstem auditory, visual, and somatosensory evoked potentials in multiple sclerosis patients. Eight clinically stable patients with abnormal visual and/or ...
The largest changes of the amplitude of the visual evoked potential, in respect to wakefulness, occur during the phases of sleep electroencephalographically characterized by spindles and slow waves. In this sleep state the amplitude is markedly increased....
The effects of alterations in body temperature on flash and pattern reversal evoked potential (FEPs and PREPs) were examined in hooded rats whose thermoregulatory capacity was compromised with lesions of the preoptic/anterior hypothalamic area and/or cold restraint. Body temperat...
Focal lesions were placed in the visual cortex of Long-Evans hooded rats, immediately below skull screw recording electrodes. Lesions were produced by heat and extended an average depth of about 0.9 mm below the cortical surface. Evoked potentials recorde...
Focal lesions were placed in the visual cortex of Long-Evans hooded rats, immediately below skull screw recording electrodes. Lesions were produced by heat and extended an average depth of about 0.9 mm below the cortical surface. Evoked potentials recorded from the electrode over...
Five main components, having different polarities and latencies, are usually recognized in the visual potential evoked during wakefulness. Their behavior during sleep is dissimilar. The short latency's components are little affected by sleep. The main cha...
The volatile organic compound 2,2,4-trimethylpentane (TMP, �isooctane�) is a primary constituent of gasoline for which the current health effects data are insufficient to permit EPA to conduct a risk assessment. We evaluated potential neurological impairment from acute inhalati...
The hypothesis that chlordimeform increased the amplitude of components N;P1 and P1N3 in rat pattern-reversal visual evoked potentials through actions on alpha2 adrenergic receptors was tested. Yohimbine alone had no effect on pattern-reversal evoked potential amplitude. Clonidin...
Results for sensory thalamocortical latency (3 somatosensory evoked potentials) for 205 college students agree with data that correlate a more extensive visual evoked potential latency with intelligence quotient. Findings suggest that the correlation occurs because the latency indexes cortical nerve conduction ...
Hawkes CH, Chawda S, Derakshani S, Muhammed N, Visentin E, Boniface D. MRI and visual-evoked potentials in partners of multiple sclerosis patients. Acta Neurol Scand: DOI: 10.1111/j.1600-0404.2011.01586.x. � 2011 John Wiley & Sons A/S. Objective -? Some epidemiological evidence, particularly concerning the role of Epstein Barr Virus implies that multiple sclerosis (MS) ...
Patients with photosensitive epilepsy are susceptible to seizures due to photoparoxysmal response (PPR). This response adversely precipitates factors that modify the functional status of the visual system. Such factors may or may not be evident superficially, but may lead to ocular defects due to trauma, hormonal imbalance, abnormal intraocular pressure (IOP), or any other ...
Aim: To perform genealogical and clinical studies in Finnish families with X linked ocular albinism (OA1), including characterisation of the potential misrouting of optic fibres by evaluating visual evoked magnetic fields (VEFs), and to determine the mutation behind the disease.Methods: Three families with OA1 were clinically examined. ...
The technique of Brainstem Electric Response Audiometry (BERA) is a non-invasive electrophysiologic method used in comatose patients for localization of areas of neuronal and synaptic dysfunction not evident in clinical evaluation. This test has a diagnostic and prognostic value in detection of abnormalities and evaluation of comatose head-injured patients at a reversible ...
Whereas much is known about the degenerative effects of aging on cortical tissue, less is known about how aging affects visually evoked electrical activity, and at what latencies. We compared visual processing in elderly and young controls using a visual masking paradigm, which is particularly sensitive to detect temporal processing deficits, while ...
of 5.25� vertically and horizontally. The second was a standard checkerboard pat- tern, as seen in Fig of 0.65� both horizon- tally and vertically, while the checkerboard as a whole subtended visual angles of 5.25� vertically and horizontally. In the case of both the snowflake images and the checkerboard
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Used steady-state probe topography to investigate the cortical activity of 12 average and 12 high IQ Australian college students during a spatial working memory task. Results, in terms of changes in visual evoked potentials, suggest that the areas of the brain involved in working memory are influenced by individual differences in ...
This study was designed to assess the effects of diesel exhaust on the development of the nervous system in rats as measurably somatosensory and visual evoked potentials (SEPs an VEPs, respectively). SEPs, elicited by 1 mamp, 0.5 msec pulses delivered to the tibial nerve at the t...
scanning in human memory. Science 153:652-654. Thorpe S, Fize D, Marlot C (1996) Speed of processing) Sound alters visual evoked potentials in humans. Neuroreport 12:3849-3852. Sternberg S (1966) High-speed (ERPs) while human subjects performed a recognition-memory task. The task's difficulty was graded
Administration of high doses of monosodium glutamate (MSG) to rats during the first postnatal week results in severe losses of retinal ganglion cells and interneurons in the retina. his study was conducted to determine what effect this severe retinal damage would have upon the on...
A comparative study was made of the visual evoked response in some neurological conditions having in common a decrease of the level of consciousness with delta activity in the EEG, but differing in their origin (deep sleep, barbiturate narcosis, post-elec...
Rat visual function was tested after acute exposure to chlordimeform (CDM), a formamidine insecticide/acaricide. Adult male Long-Evans rats were surgically implanted with epidural recording electrodes overlying visual cortex and tested 1 week later. Patte...
Rat visual function was tested after acute exposure to chlordimeform (CDM), a formamidine insecticide/acaricide. Adult male Long-Evans rats were surgically implanted with epidural recording electrodes overlying visual cortex and tested 1 week later. Pattern reversal-evoked potent...
The hypothesis that chlordimeform increased the amplitude of components N;P1 and P1N3 in rat pattern-reversal visual evoked potentials through actions on alpha2 adrenergic receptors was tested. Yohimbine alone had no effect on pattern-reversal evoked pote...
Previous experiments have shown the effects of acute inhalation exposure to trichloroethylene (TCE) and toluene are related to the target tissue concentration at the time of testing. The current studies examined exposure to another volatile organic compound, perchloroethylene (P...
Many studies report chronic deficits in visual processing in children born preterm. We investigated whether functional abnormalities in visual processing exist in children born preterm but without major neuromotor impairment (i.e. cerebral palsy). Twelve such children (less than 33 weeks gestation or birthweight less than 1000 g) without major neuromotor impairment and 12 born ...
Expression of the constitutively active serine/threonine kinase Akt in oligodendrocytes results in enhanced myelination in the CNS. Here, we have examined the effects of this Akt overexpression on optic nerve structure and on optic nerve function, assessed using the visual evoked potential (VEP). Transgenic mice have been generated ...
To test whether multifocal visual evoked potential (mfVEP) recording using two perpendicularly placed channels, as previously reported, to measure the degree of signal-to-noise ratio (SNR) distribution overlap between a signal window and a noise window would efficiently detect and quantify glaucomatous damage. Humphrey visual field ...
NrCAM is a neural cell adhesion molecule of the L1 family that has been linked to autism spectrum disorders (ASDs), a disease spectrum in which abnormal thalamocortical connectivity may contribute to visual processing defects. Here we show that NrCAM interaction with Neuropilin-2 (Npn-2) is critical for Semaphorin3F (Sema3F)-induced guidance of thalamocortical axon ...
We retrospectively reviewed the medical records of neonates with chromosomal abnormalities and epilepsy who had been admitted to the neonatal intensive care unit (NICU) and followed up at the outpatient clinic of Dokkyo University School of Medicine. Chromosomal anomalies were diagnosed in 128 of 5789 patients admitted from 1978 through 2001. Seventy-one neonates had trisomy ...
... Title : Nitrogen Narcosis and Visual Evoked Responses in the Unanesthetized Cat. Descriptive Note : Medical research progress rept. no. 8,. ...
A lack of habituation in visual-evoked potentials (VEPs) is the main abnormality observed in migraineurs. However, no study of steady-state VEPs has yet evaluated pattern-reversal stimuli with respect to habituation behavior or spatial frequency. The aim of this study was to clarify habituation behavior in migraineurs between attacks and to establish ...
Little is known on the disturbances of lung epithelium function in aluminum casting smelters and shipyard welders exposed by inhalation to irritant occupational pollutants, dust and fumes. The exact mechanism of aluminum and manganese toxicity is not known, but it is thought that they may potentiate oxidative and inflammatory stress, leading to impaired neurological function. ...
Sixty-four children, aged 7 to 14�years, with early-treated PKU, were compared with control children on visual evoked potential (VEP) amplitudes and latencies and auditory mismatch negativity (MMN) amplitudes. It was further investigated whether indices of dietary control would be associated with these evoked ...
Electrical potentials evoked in the human brain by visual stimulation can easily be recorded by using electrodes attached to the scalp. It is difficult, however, to relate these visual evoked potentials (VEPs) to specific neural processes: scalp electrodes, far removed from the brain, sum ...
Visual evoked potentials in response to images of a set of horizontal and vertical lines or crosses were recorded from the brains of 18 human subjects in 34 leads. Inverse EEG analyses were used for the dynamic location of the dipole current sources of the N1, P1, and N2 waves using a two-dipole spherical model with a 1-msec step. The ...
ObjectiveTo establish whether people exposed to drinking water contaminated with 20 tonnes of aluminium sulphate in the Camelford area of Cornwall in the south west of England in July 1988 had suffered organic brain damage as opposed to psychological trauma only.DesignRetrospective study of affected people.Participants55 affected people and 15 siblings nearest in age to one of the group but who ...
Optic neuropathy is common in mitochondrial disorders, but poorly characterized in Friedreich's ataxia (FRDA), a recessive condition caused by lack of the mitochondrial protein frataxin. We investigated 26 molecularly confirmed FRDA patients by studying both anterior and posterior sections of the visual pathway using a new, integrated approach. This included visual field testing and optical ...
Aim: To study the maturation of multifocal visual evoked potentials (multifocal VEP) in normal children between the ages of 5 and 16 years and to apply the results clinically in selected cases to the diagnosis of optic pathway diseases.Method: 70 normal children were recruited from the community and multifocal VEP (Accumap ...
The aim of this study was to investigate the relationship between the workers occupationally exposed to a mixture of organic solvents and their visual functions. Here the visual functions included color vision (CV), visual contrast sensitivity (CS) and visual evoked potentials (VEP). Test subjects were 182 workers at 53 furniture ...
Optic neuritis (ON) is a rare neurological complication of measles infection. Little is known about measles-associated retrobulbar ON. Here, we report a distinct patient with unilateral retrobulbar ON due to measles infection. A 26-year-old woman developed maculopapular rash and Koplik spots. On the following 3 days, she noticed blurred vision in the left eye. A Goldmann visual field test showed ...
Schizophrenia patients (SZ) show early visual processing deficits in many, but not all, tasks. These deficits may be associated with dysregulation of intrinsic oscillatory activity that compromises signal-to-noise in the SZ brain. This question was studied using visual steady-state stimulation and post-steady-state presentation of transient visual stimuli. SZ had higher intrinsic oscillatory ...
Background and PurposeMultiple sclerosis (MS) in Asians is characterized by frequent involvement of the spinal cord and optic nerve and low prevalence rates, but even the most fundamental epidemiologic findings and unique clinical features of MS patients in Korea have not been studied extensively. We performed this study to establish the clinical spectrum of MS patients in Korea.MethodsSixty-two ...
Background: We conducted a study to determine the incidence of multiple sclerosis (MS) among the whole Icelandic population during a 6-year period (2002-2007). Methods: We included all Icelandic residents diagnosed with MS during the study period. Cases were identified from records of the only neurology department in Iceland, plus the records of all practicing neurologists and all radiology ...
In this investigation, the relationships between stretch and both morphological and electrophysiological signs of axonal injury were examined in the guinea pig optic nerve stretch model. Additionally, the relationship between axonal morphology and electrophysiological impairment was assessed. Axonal injury was produced in vivo by elongating the guinea pig optic nerve between 0 and 8 mm (Ntotal = ...
Purpose.To compare glaucoma progression by functional and structural tests.Methods.The authors prospectively studied 33 glaucoma patients (55 eyes); 20 eyes (15 patients) had disc hemorrhage, and 35 eyes (18 patients) had exfoliation glaucoma. The following tests were performed at two baseline and three follow-up examinations: frequency doubling perimetry (FDT), 24-2 Humphrey visual fields (HVF), ...
