PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Color Perception Tests”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,621 records · Page 90Linked to original sources
PubMed2000

Impaired distractor inhibition on a selective attention task in unmedicated, depressed subjects.

BACKGROUND: Impaired distractor inhibition may contribute to the selective attention deficits observed in depressed patients, but studies to date have not tested the distractor inhibition theory against the possibility that processes such as transient memory review processes may account for the observed deficits. A negative priming paradigm can dissociate inhibition from such a potentially confounding process called object review. The negative priming task also isolates features of the distractor such as colour and location for independent examination. METHOD: A computerized negative priming task was used in which colour, identification and location features of a stimulus and distractor were systematically manipulated across successive prime and probe trials. Thirty-two unmedicated subjects with DSM-IV diagnoses of non-psychotic unipolar depression were compared with 32 age, sex and IQ matched controls. RESULTS: Depressed subjects had reduced levels of negative priming for conditions where the colour feature of the stimulus was repeated across prime and probe trials but not when identity or location was the repeated feature. When both the colour and location feature were the repeated feature across trials, facilitation in response was apparent. CONCLUSIONS: The pattern of results supports studies that found reduced distractor inhibition in depressed subjects, and suggests that object review is intact in these subjects. Greater impairment in negative priming for colour versus location suggests that subjects may have greater impairment in the visual stream associated with processing colour features.

Adolescent↗
PubMed1991

Foveal cone detection statistics in color-normals and dichromats.

We measured for six male observers, the psychometric functions for the detection of two simultaneously presented points of light. The test stimuli were two 1 min point sources separated by 17 min arc, and pulsed for 0.5 msec. The stimuli varied in wavelength from 500 to 620 nm. The psychometric functions were fit with a model that assumes ideal detection and the following properties: (1) Poisson-distributed quantal absorptions; (2) binomial sampling of foveal long-wavelength-sensitive (LWS) and middle-wavelength-sensitive (MWS) cones; (3) independent responses of the LWS and MWS cones; and (4) the Smith-Pokorny fundamentals for cone spectral sensitivities. Based on chi 2 fits to the psychometric functions for detecting neither, one or both of the two-point stimuli presented, estimates were derived for the minimum quantal catch by a single cone for detection (C), the number of effective cones illuminated by a point stimulus at threshold (N) and the proportion of central foveal cones of the LWS type (PL). Three observers were color-normal, two were protanopes and one was a deuteranope. A second deuteranope was included in the design but his data were too unreliable for an unambiguous solution. The estimated quantal requirement C was consistently near 5(4-6), and the effective number of illuminated cones always was 1 or 2. The plausible range of PL (98% confidence interval) for the color-normal observers was 0.48-0.68 (observer YY), 0.76-0.90 (observer MW) and 0.77-0.95 (observer DF). The best fitting PL solution for these observers were 0.61, 0.82 and 0.88, respectively. These were comparable to the values obtained from flicker photometric data. The best PL value for each of the protanopes was 0.00 and for the deuteranope the best PL value was 0.98.

Color Perception↗
PubMed2005

Novel NR2E3 mutations (R104Q, R334G) associated with a mild form of enhanced S-cone syndrome demonstrate compound heterozygosity.

PURPOSE: We investigated the ophthalmic features of a mild form of enhanced S-cone syndrome (ESCS) in a 33-year-old Japanese female proband and 3 unaffected family members. A genetic analysis was performed. DESIGN: Genetic and observational case study. METHODS: Fundus examinations, optical coherence tomography (OCT), Goldmann visual field (VF) perimetry, color vision tests, spectral sensitivity, and full-field and spectral electroretinography (ERG) were performed. Mutation screening of the NR2E3 gene, which encodes a photoreceptor-specific orphan nuclear receptor, was performed with polymerase chain reaction amplification and direct sequencing. MAIN OUTCOME MEASURES: Mutations in the NR2E3 gene, fundus photographs, OCT images, VFs, spectral sensitivity, and ERG findings. RESULTS: The diagnosis of ESCS was made based on the distinctive spectral ERG findings: hypersensitivity to blue stimuli and hyposensitivity to red stimuli. The proband had good visual acuity, normal color vision, good central VFs, and nearly normal spectral sensitivity. Funduscopy showed degenerative lesions in the vascular arcades to the midperipheral retina. The OCT images showed a morphologically normal macular thickness. In the full-field ERG, low amplitudes of rod b-waves were detected. Waveforms between rod-plus-cone and cone ERGs were very similar. Mutation analysis identified 2 novel compound heterozygous missense mutations, p.R104Q and p.R334G, which reside in the DNA-binding domain (DBD) and ligand-binding domain (LBD), respectively. The unaffected parents carried one of these mutations each, consistent with autosomal recessive transmission. CONCLUSIONS: Our study suggests that the expression of these 2 mutants of NR2E3, acting as a dimer, is correlated with a mild form of ESCS in that full foveal function and retinal laminar structure are maintained, and certain rod responses are present. This may be explained by the possibility that the heterodimers encoded by the 2 mutant alleles retain certain NR2E3 functions through the respective intact DBD and LBD.

Adult↗
PubMed2000

Autosomal dominant hemorrhagic macular dystrophy not associated with the TIMP3 gene.

OBJECTIVE: To describe the ophthalmic and genetic findings of a large kindred (UM:H389) with autosomal dominant hemorrhagic macular dystrophy. METHODS: The disease state of family members was documented by dilated fundus examination, electroretinography, color vision tests, fluorescein angiography, measurement of visual fields, biomicroscopy, gonioscopy, and intraocular pressure measurement. Linkage and haplo-type analyses were carried out with markers flanking the Sorsby fundus dystrophy TIMP3 (tissue inhibitor of metalloproteinase 3) gene locus, and mutation analysis was carried out by screening exon 5 of the TIMP3 gene. RESULTS: This 4-generation pedigree with autosomal dominant hemorrhagic macular degeneration has visual symptoms beginning in the sixth decade of life. Several family members developed choroidal neovascular membrane formation in the macula of both eyes. The phenotype overlaps that of Sorsby fundus dystrophy. Some of the affected members have unusual zonularlike radial striations on the anterior lens capsule surface, and glaucoma or ocular hypertension has developed in 2 of them. Involvement of the TIMP3 gene was excluded by linkage, haplotype, and mutation analyses. CONCLUSIONS: The phenotype of this family with autosomal dominant macular dystrophy overlaps that of Sorsby fundus dystrophy. Exclusion of the TIMP3 gene in this family indicates genetic heterogeneity for hemorrhagic macular dystrophy. Anterior segment anomalies may occur with this condition, but cosegregation has not yet been established. CLINICAL RELEVANCE: This study broadens the spectrum of hemorrhagic macular dystrophy by identifying a family in which the TIMP3 gene is not involved. Once the gene is cloned, we are eager to learn whether this gene may be involved in age-related macular degeneration.

Adult↗
PubMed1976

Color perimetry.

Seven subjects were studied to determine the reproducibility of color isopters utilizing a Tubingen perimeter with targets equated for radiant energy and separate for heterochromatic flicker luminance. Achromatic threshold recognition of targets for equal luminance gave smaller isopters with longer wavelengths (red). Color recognition thresholds, on the other hand, showed large blue, midzone red and green, and small yellow isopters. The target recognition and color recognition thresholds for equal energy targets gave smaller red isopters. The data support Traquair's contention that all color isopters would be equivalent if hue, saturation, and intensity were equated. Clinically, the detection of subtle peripheral and central field defects might reside in the use of appropriately selected equally bright-colored targets.

Color Perception↗
PubMed1979

Photoreceptor misalignment accompanying a fibrous scar.

A 9-year-old boy with dense fibrous scars at the macula had visual acuities of 6/12 and 6/9 and an abnormal color match (pseudoprotanomaly). The Stiles-Crawford effect functions were abnormal in both eyes, showing maximal sensitivity at the nasal edge of each pupil. The data suggest that the foveal photoreceptors, although spared destruction by an adjacent focus of healed chorioretinitis, have been distorted by fibrous traction arising from that defect.

Child↗
PubMed1983

Clinical studies of color vision with Gunkel's chromagraph.

Color thresholds in a series of patients with local or systemic diseases were determined by a chromagraph method and subjected to computer analysis. When compared with normal persons, those with optic nerve disease (multiple sclerosis, optic neuritis, and optic atrophy) showed an overall weakness for all colors (enlarged neutral areas), with an additional specific defect in the orange-cyan (greenish blue) axis. Those with the two retinal diseases studied (macular degeneration and retinitis pigmentosa) also showed threshold elevation for all colors, but with a special defect in the yellow-blue axis. The general elevation was greater for patients with retinitis pigmentosa than for those with macular degeneration, regardless of the visual acuity. In patients undergoing treatment for systemic lupus erythematosus and rheumatoid arthritis, there was a mild elevation of the color threshold, especially for yellow.

Arthritis, Rheumatoid↗
PubMed1988

Assessment of visual function in patients with age-related macular degeneration and low visual acuity.

The visual function of 100 eyes with low visual acuity of 100 patients with age-related macular degeneration was examined using measurements of visual acuity, peak contrast sensitivity, and the ability to read, to tell time, and to distinguish colors, products, and facial expressions. Visual acuity and peak contrast sensitivity were correlated (r = .62); however, a range of peak contrast sensitivities was observed at each level of acuity. When considered individually, visual acuity and peak contrast sensitivity were related to the ability to perform each of the tasks. When multivariate methods were applied, both visual acuity and peak contrast sensitivity contributed independently to the ability to read and tell time. Among patients with the same contrast sensitivity, visual acuity had little or no relationship to the ability to identify colors, products, and faces.

Aged↗
PubMed1999

Changes in phosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) in processing of short-term and long-term memories after passive avoidance learning.

Characteristic autophosphorylation of calcium/ calmodulin-dependent protein kinase II (CaMKII) and its consequences have made this kinase an interesting target in studying the molecular pathway for important neuronal functions including learning and memory formation. In this article, we use immunoprecipitation and immunoblotting methods to detect changes in phosphorylation of CaMKII during memory formation in 1-day-old chicks trained in a single trial passive avoidance task. A 60-kDa protein has been immunoprecipitated from the chick brain with an anti-rabbit CaMKII antibody. This protein shows strong and specific immunoactivities with antibodies against the calmodulin binding site of CaMKII, and the N and C terminals of beta-CaMKII. Commercially available anti-phosphoserine and anti-phosphothreonine antibodies are shown to sensitively detect phosphorylation of purified CaMKII. The basal phosphorylation of CaMKII from the intermediate medial hyperstriatum ventrale (IMHV) and lobus parolfactorius (LPO) regions of the chick brain is shown to be largely right hemisphere-lateralized. When chicks are subjected to a passive avoidance training experience, a specific increase in CaMKII phosphorylation is induced in the IMHV and LPO of the left hemisphere from those chicks whose memory for the training experience is successfully retrieved. While this specific increase in CaMKII phosphorylation is seen in both the left IMHV and left LPO in short-term memory, it is detectable only in the left LPO associated with long-term memory retrieval. The present results provide evidence that in vivo changes in phosphorylation of CaMKII are associated specifically with processing of distinct memory stages, which take place in specific brain regions.

3T3 Cells↗
PubMed1983

Genetic markers and alcoholism.

Genetic markers are genetically determined characteristics that have been found to occur in association with some common disorders. In alcoholism, four types of genetic markers have been studied to determine their frequency compared with the general population frequency. The markers studied are blood groups and serum proteins, secretion of ABH blood group substance, phenylthiourea taste sensitivity, and color vision defects. There have been found to be significant associations between alcoholism and all the above markers apart from blood groups and serum proteins. However, the associations appear to result from acquired rather than inherited factors.

ABO Blood-Group System↗
PubMed1984

Results from a simple laser color perimeter.

Stimulus size, chromaticity, adaptation, luminance and local adaptation are more easily controlled when laser light rapidly scans the appropriate portion(s) of the visual field. Adaptation of a Ferree-Rand perimeter to the use of He-Ne laser light gives chromatic and achromatic thresholds of relatively low variance.

Adaptation, Ocular↗
PubMed1976

Sensorio-motorial anomalies in strabismus: (anomalous movements).

The attempts at treating anomalous correspondence by prisms in esotropia have led to the observation that frequently the angle of deviation increases with prismatic correction. The convergent movements induced by base-out prisms in esotropic patients resemble normal fusional movements in some aspects; they are provisorily called 'anomalous movements' and the objective differences between anomalous movements and normal fusional movements are reported. The strength of 'anomalous movements' are investigated with prisms. This with the aim of better understanding this sensorio-motorial sequela of strabismus and possibly selecting those patients who are more apt for prismatic therapy. The main criteria adopted today for eliminating anomalous movements and the residual postoperative deviation related with them are listed. Finally, the way anomalous movements may interfere with surgery is discussed.

Color Perception Tests↗
PubMed1986

Atypical sector pigmentary dystrophy.

The authors describe a family with atypical sector shaped pigmentary dystrophy in two generations with transmission from father to son. A review of the literature is given.

Adult↗
PubMed1992

Stargardt's disease. Family studies.

Three families including seven members with Stargardt's disease were examined. In addition to the affected family members, 43 of the relatives had an eye examination. In one family, there was a consanguineous marriage to be found. The heredity was most probably autosomal recessive in all of the three families. The ages of the seven patients with Stargardt's disease varied from 13 to 50 years, visual acuities from 0.05 to 1.0, and refraction from -8.5 to +2.25 D. In fundus, absent foveal reflex, atrophic macular spots and yellow perimacular flecks could be observed; one patient had also yellow flecks in the peripheral retina. In the visual fields, a central scotoma was found in five patients. Dark adaptation was abnormal in three patients and electroretinogram in one patient. All of the patients had defective red colour vision. In the fluoresceinangiogram, hyperfluorescent macular spots and dark choroid could be observed. The ophthalmological findings are discussed comparing them to the earlier observations of this disease.

Adolescent↗