Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 2726165

The (+/-) reference in pattern electroretinogram recording.

P Bobak
View original source ↗Export metadata ↓

Abstract

In this communication, the value of using a simultaneously acquired estimate of background noise, the (+/-) reference, is demonstrated in pattern electroretinogram (PERG) recording. During the signal averaging process, the (+/-) reference inverts the polarity of every other sweep; cycle-locked (stimulus-related) activity is thus cancelled out, leaving a noise distribution similar in statistical properties to that of the signal average. Assessing the presence of a PERG response by comparing the spectrum analysis of the PERG trace with that of the (+/-) reference is discussed. The results of the normal controls and patient groups are summarized and the raw waveforms from a representative normal observer and a patient with optic nerve damage are analyzed.

Explore related subjects

ElectroretinographyHumansOptic Nerve DiseasesComparative StudyJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

P Bobak. 1989. The (+/-) reference in pattern electroretinogram recording.. https://doi.org/10.1097/00006324-198904000-00007

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2000

Visual motion detection in man is governed by non-retinal mechanisms.

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 testing the direction specificity of motion adaptation with three conditions in a fully balanced paradigm: motion-onset potentials were measured after adaptation to: (1) a stationary pattern; (2) motion in the same direction as the test stimulus; and (3) motion in the opposite direction. Motion-onset responses in the VEP were dominated by the typical N2 at 150 ms, in the ERG by a positivity at 70 ms. Onset of contraction or expansion evoked virtually identical VEP and ERG responses (P>0.5). Motion adaptation produced strong direction-specific effects in the VEP (P<0.05), but not in the ERG (P=0.58): In the adapting and non-adapting direction the VEP (N2) was reduced by 75 and 50% (P<0.001), the ERG by 32 and 26% (P<0.01 and 0.05), respectively. The striking difference of the direction-specificity of motion adaptation between cortex and retina suggests that in humans the vast majority of motion-specific processing occurs beyond the retinal ganglion cells.

Electroretinography↗