Linked Life Data

15518231

Source:http://linkedlifedata.com/resource/pubmed/id/15518231

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2004-11-2
pubmed:abstractText
An automated, computerized color-vision test was designed to diagnose congenital red-green color-vision defects. The observer viewed a yellow appearing CRT screen. The principle was to measure increment thresholds for three different chromaticities, the background yellow, a red, and a green chromaticity. Spatial and temporal parameters were chosen to favor parvocellular pathway mediation of thresholds. Thresholds for the three test stimuli were estimated by four-alternative forced-choice (4AFC), randomly interleaved staircases. Four 1.5-deg, 4.2 cd/m2 square pedestals were arranged as a 2 x 2 matrix around the center of the display with 15-minute separations. A trial incremented all four squares by 1.0 cd/m2 for 133 ms. One randomly chosen square included an extra increment of a test chromaticity. The observer identified the different appearing square using the cursor. Administration time was approximately 5 minutes. Normal trichromats showed clear Sloan notch as defined by log (deltaY/deltaR), whereas red-green color defectives generally showed little or no Sloan notch, indicating that their thresholds were mediated by their luminance system, not by the chromatic system. Data from 107 normal trichromats showed a mean Sloan notch of 0.654 (SD = 0.123). Among 16 color-vision defectives tested (2 protanopes, 1 protanomal, 6 deuteranopes, & 7 deuteranomals), the Sloan notch was between -0.062 and 0.353 for deutans and was < -0.10 for protans. A sufficient number of color-defective observers have not yet been tested to determine whether the test can reliably discriminate between protans and deutans. Nevertheless, the current data show that the test can work as a quick diagnostic procedure (functional trichromatism or dichromatism) of red-green color-vision defect.
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:issn
0952-5238
pubmed:author
pubmed:issnType
Print
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
465-9
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:articleTitle
Computerized color-vision test based upon postreceptoral channel sensitivities.
pubmed:affiliation
Department of Psychology, California State University, Fullerton, 92834-6846, USA. emiyahara@fullerton.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.