Document Detail

The effect of contrast and spatial frequency on the visual evoked potential of the hooded rat.
MedLine Citation:
PMID:  6519219     Owner:  NLM     Status:  MEDLINE    
Transient and steady-state visual evoked potentials, obtained with counterphase modulated grating patterns, were recorded through chronically implanted electrodes in lightly anesthetized and unanesthetized hooded rats. As a function of spatial frequency, the latency of the major positive wave (P1) of the transient VEP was minimal with a 0.1 cycles per degree (cpd) grating as stimulus. The amplitude of the P1-N2 component remained constant from 0.04 to 0.20 cpd and then decreased with higher spatial frequencies. The function relating amplitude of steady-state VEP to spatial frequency at high contrast depended on temporal frequency: It had a band-pass form at 5.0 Hz and a low-pass form at 8.4 Hz. As a function of contrast, the latency of the P1 wave linearly decreased and its amplitude increased with increments of contrast up to 55%. The contrast function of the amplitude of the second harmonic of the steady-state VEP (8.4 Hz) showed two linear segments: one for low contrasts with a shallow slope and one for high contrasts with a steep slope, suggesting two distinct contrast mechanisms.
C Harnois; I Bodis-Wollner; M Onofrj
Related Documents :
8447109 - Individual differences in contrast sensitivity functions: the first four months of life...
9274769 - Contrast dependency of motion-onset and pattern-reversal veps: interaction of stimulus ...
6740979 - Spatiotemporal conditions which elicit or abolish the oblique effect in man: direct mea...
2679809 - Perceptual characteristics in visual laterality research.
8646179 - Objective measurement of contrast sensitivity and visual acuity with the steady-state v...
6506469 - A study of stimulus range effects in free modulus magnitude estimation of contrast.
8814649 - Effects of ethanol and auditory distraction on forced choice reaction time.
2373719 - Ultimate strength of the lumbar spine in flexion--an in vitro study.
21463599 - Time-dependent nanomechanics of cartilage.
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Experimental brain research     Volume:  57     ISSN:  0014-4819     ISO Abbreviation:  Exp Brain Res     Publication Date:  1984  
Date Detail:
Created Date:  1985-02-25     Completed Date:  1985-02-25     Revised Date:  2013-12-13    
Medline Journal Info:
Nlm Unique ID:  0043312     Medline TA:  Exp Brain Res     Country:  GERMANY, WEST    
Other Details:
Languages:  eng     Pagination:  1-8     Citation Subset:  IM; S    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Biophysical Phenomena
Evoked Potentials, Visual
Genetic Variation
Geniculate Bodies / cytology,  physiology
Species Specificity
Visual Acuity
Visual Pathways / physiology*
Visual Perception / physiology*
Grant Support

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Interstitial pneumopathy and low-dosage amiodarone.
Next Document:  Single cell activity in area 18 of the cat's visual cortex during optokinetic nystagmus.