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The Journal of Physical Chemistry... Jan 2024The human brain efficiently processes only a fraction of visual information, a phenomenon termed attentional control, resulting in energy savings and heightened...
The human brain efficiently processes only a fraction of visual information, a phenomenon termed attentional control, resulting in energy savings and heightened adaptability. Translating this mechanism into artificial visual neurons holds promise for constructing energy-efficient, bioinspired visual systems. Here, we propose a self-rectifying artificial visual neuron (SEVN) based on a NiO/GaO bipolar heterojunction with attentional control on patterns with a target color. The device exhibits short-term potentiation (STP) with quantum point contact (QPC) traits at low bias and transitions to long-term potentiation (LTP) at high bias, particularly facilitated by electron capture in deep defects upon ultraviolet (UV) exposure. With the utilization of two wavelengths of light upon the target and interference part of CAPTCHA to simulate top-down attentional control, the recognition accuracy is enhanced from 74 to 84%. These findings have the potential to augment the visual capability of neuromorphic systems with implications for diverse applications, including cybersecurity, healthcare, and machine vision.
Topics: Humans; Synapses; Brain; Neurons
PubMed: 38198134
DOI: 10.1021/acs.jpclett.3c02898 -
Rationally blind? Rationality polarizes policy support for colour blindness versus multiculturalism.The British Journal of Social Psychology Jan 2024Do White Americans prefer society to be 'colour-blind' by rising above racial identities, or 'multicultural' by openly discussing and considering them? We developed an...
Do White Americans prefer society to be 'colour-blind' by rising above racial identities, or 'multicultural' by openly discussing and considering them? We developed an ideology-rationality model to understand support for these diversity perspectives. Specifically, since people endorse a diversity perspective in line with their ideological values, we hypothesized that conservatism is related to a relative preference for colour blindness over multiculturalism. However, since colour blindness and multiculturalism are complex and multi-layered ideologies, we further hypothesized that the relationship between conservatism and a preference for colour blindness over multiculturalism is especially pronounced under higher levels of rationality. Results confirmed the hypotheses, either when rationality was operationalized within a dual process theory (Study 1, N = 496) or experimentally induced within a tripartite model of cognition (Study 2, N = 497). Higher levels of rationality guided White Americans high in conservatism towards a stronger preference for colour-blindness, but those low in conservatism towards a stronger preference for multiculturalism. These results suggest that among White Americans the endorsement of colour blindness versus multiculturalism stems from the interplay between ideological orientation and rationality and that rational considerations about racial policies may further divide rather than unify along ideological lines.
Topics: Humans; Prejudice; Color Vision Defects; Blindness; Cultural Diversity; White
PubMed: 37357843
DOI: 10.1111/bjso.12667 -
The New England Journal of Medicine Feb 2024
Topics: Humans; Color Vision Defects; Heredity; Art
PubMed: 38314808
DOI: 10.1056/NEJMp2312346 -
BMC Medical Genomics Jul 2024Autosomal recessive non-syndromic hearing loss (NSHL) and cone dystrophies (CODs) are highly genetically and phenotypically heterogeneous disorders. In this study, we...
Clinical characterizations and molecular genetic study of two co-segregating variants in PDZD7 and PDE6C genes leading simultaneously to non-syndromic hearing loss and achromatopsia.
BACKGROUND
Autosomal recessive non-syndromic hearing loss (NSHL) and cone dystrophies (CODs) are highly genetically and phenotypically heterogeneous disorders. In this study, we applied the whole exome sequencing (WES) to find the cause of HL and COD in an Iranian consanguineous family with three affected individuals.
METHODS
Three members from an Iranian consanguineous family who were suffering from NSHL and visual impairment were ascertained in this study. Comprehensive clinical evaluations and genetic analysis followed by bioinformatic and co-segregation studies were performed to diagnose the cause of these phenotypes. Data were collected from 2020 to 2022.
RESULTS
All cases showed congenital bilateral NSHL, decreased visual acuity, poor color discrimination, photophobia and macular atrophy. Moreover, cornea, iris and anterior vitreous were within normal limit in both eyes, decreased foveal sensitivity, central scotoma and generalized depression of visual field were seen in three cases. WES results showed two variants, a novel null variant (p.Trp548Ter) in the PDE6C gene causing COD type 4 (Achromatopsia) and a previously reported variant (p.Ile84Thr) in the PDZD7 gene causing NSHL. Both variants were found in the cis configuration on chromosome 10 with a genetic distance of about 8.3 cM, leading to their co-inheritance. However, two diseases could appear independently in subsequent generations due to crossover during meiosis.
CONCLUSIONS
Here, we could successfully determine the etiology of a seemingly complex phenotype in two adjacent genes. We identified a novel variant in the PDE6C gene, related to achromatopsia. Interestingly, this variant could cooperatively cause visual disorders: cone dystrophy and cone-rod dystrophy.
Topics: Humans; Color Vision Defects; Cyclic Nucleotide Phosphodiesterases, Type 6; Male; Female; Pedigree; Exome Sequencing; Adult; Hearing Loss; Mutation; Consanguinity; Child; Iran; Phenotype; Eye Proteins
PubMed: 38956522
DOI: 10.1186/s12920-024-01942-3 -
Indian Journal of Ophthalmology Nov 2023This study aimed to evaluate color perception (CP) changes on Ishihara plates following red-tinted contact lenses in subjects with low vision (LV) from retinal diseases. (Observational Study)
Observational Study
PURPOSE
This study aimed to evaluate color perception (CP) changes on Ishihara plates following red-tinted contact lenses in subjects with low vision (LV) from retinal diseases.
METHODS
A cross-sectional observational study without control involved 84 subjects, aged 20-70 years, having LV from retinal diseases to examine CP changes following wearing red-tinted contact lenses. The subjects viewed Ishihara plates, with each eye separately, before and after wearing red lenses in two categories: "plates 1-21" and "plates 22-25". Change in CP with the use of a red lens was the primary outcome measure.
RESULTS
There was a significant increase in the number of plates read in both categories, that is, plates 1-21 (P = 0.002) and plates 22-25 (P = 0.032), the latter being used to diagnose the red-green defects. Although 70 eyes could read both digits on plates 22-25 and appeared to have normal color vision (CV) at baseline, this number rose to 99 eyes following the use of red-tinted lenses. There was a significant change in the type of CP (red defect/green defect/normal/undefined defect) (P = 0.022) with the application of a red-tinted lens.
CONCLUSIONS
The use of red-tinted lenses caused a significant increase in the number of plates read, increased the number of subjects who appeared normal on plates 22-25, and significantly changed CP of LV subjects. These lenses can be a valuable aid for LV subjects. Although Ishihara plates can diagnose only red-green defects, further studies on CV testing techniques that detect both red-green and blue-yellow CV defects are recommended.
Topics: Humans; Color Perception; Vision, Low; Cross-Sectional Studies; Vision Tests; Color Vision Defects; Retinal Diseases; Color Vision
PubMed: 37870020
DOI: 10.4103/IJO.IJO_2532_22 -
International Journal of Molecular... Oct 2023This study aimed to investigate the prevalence of color vision deficiencies (CVDs) and determine whether carriers could be detected by analyzing the visual pigment...
This study aimed to investigate the prevalence of color vision deficiencies (CVDs) and determine whether carriers could be detected by analyzing the visual pigment genes. Materials and Methods: The data of students who underwent routine CVD screening using the Ishihara color test in Kaohsiung, Southern Taiwan were analyzed. Furthermore, the DNA samples of 80 randomly selected females and four obligate carriers were analyzed. The most upstream genes, downstream genes, and the most downstream genes in the red/green pigment gene arrays were amplified separately using polymerase chain reaction (PCR), and exon 5 of each gene was analyzed. The prevalence of congenital red-green CVD in this study was 3.46% in males and 0.14% in females. The PCR analysis of the first gene, downstream gene, and last gene revealed normal patterns in 73 normal cases. Seven unusual patterns were detected in two proton carriers and five deutan carriers. Among the randomly selected females, 8.8% (7/80) were CVD carriers. The prevalence of CVD among male Taiwanese students in this study was 3.46%. Female carriers of congenital CVD can be identified by molecular analysis of the visual pigment genes. The proportion of CVD carriers among the randomly selected females was 8.8%, which was slightly higher than expected and further studies are warranted.
Topics: Humans; Male; Female; Color Vision Defects; Color Perception; Retinal Pigments; Prevalence; Taiwan; Cardiovascular Diseases
PubMed: 37894926
DOI: 10.3390/ijms242015247 -
Sensors (Basel, Switzerland) Jul 2023Ensuring the quality of color contact lenses is vital, particularly in detecting defects during their production since they are directly worn on the eyes. One...
Ensuring the quality of color contact lenses is vital, particularly in detecting defects during their production since they are directly worn on the eyes. One significant defect is the "center deviation (CD) defect", where the colored area (CA) deviates from the center point. Measuring the extent of deviation of the CA from the center point is necessary to detect these CD defects. In this study, we propose a method that utilizes image processing and analysis techniques for detecting such defects. Our approach involves employing semantic segmentation to simplify the image and reduce noise interference and utilizing the Hough circle transform algorithm to measure the deviation of the center point of the CA in color contact lenses. Experimental results demonstrated that our proposed method achieved a 71.2% reduction in error compared with existing research methods.
PubMed: 37514827
DOI: 10.3390/s23146533 -
International Ophthalmology Jun 2024To evaluate mesopic and photopic contrast sensitivity in patients with congenital red-green color vision deficiency regarding with and without glare conditions and to... (Comparative Study)
Comparative Study
PURPOSE
To evaluate mesopic and photopic contrast sensitivity in patients with congenital red-green color vision deficiency regarding with and without glare conditions and to compare these findings with age- and gender-matched healthy controls with normal color vision.
METHODS
Patients with congenital red-green color vision deficiency and age- and gender-matched healthy controls were included in this cross-sectional comparative study. Contrast sensitivity measurements were taken from all subjects in 4 different conditions; binocular mesopic-without glare, mesopic-with glare, photopic-without glare, photopic-with glare, and the results were compared.
RESULTS
Twenty one patients with color vision deficiency (13 deuteranopic, 8 protanopic) and 22 age- and gender-matched healthy controls were included in the study. The mean age was 35.2 ± 13.5 years in the protan group, 30.6 ± 7.7 years in the deutan group, 32.0 ± 8.8 years in the control group, and there was no significant difference in age between the groups (P > 0.05). The mean mesopic and photopic contrast sensitivity values of the groups at all spatial frequencies (1.5, 3, 6, 12, 18 cpd) were not statistically significant when evaluated by the multifactor repeated measures test of ANOVA to evaluate the effect of light conditions (with and without glare) (P > .05).
CONCLUSION
Mesopic and photopic contrast sensitivity values of patients with congenital red-green color vision deficiency were similar to healthy controls regarding with and without glare conditions.
Topics: Humans; Contrast Sensitivity; Color Vision Defects; Female; Male; Cross-Sectional Studies; Adult; Color Vision; Young Adult; Middle Aged; Mesopic Vision; Glare; Visual Acuity; Adolescent
PubMed: 38916772
DOI: 10.1007/s10792-024-03160-3 -
Investigative Ophthalmology & Visual... Apr 2024Achromatopsia (ACHM) is an autosomal recessive retinal disease associated with reduced or absent cone function. There is debate regarding the extent to which cone...
PURPOSE
Achromatopsia (ACHM) is an autosomal recessive retinal disease associated with reduced or absent cone function. There is debate regarding the extent to which cone structure shows progressive degeneration in patients with ACHM. Here, we used optical coherence tomography (OCT) images to evaluate outer nuclear layer (ONL) thickness and ellipsoid zone (EZ) integrity over time in individuals with ACHM.
METHODS
Sixty-three individuals with genetically confirmed ACHM with follow-up ranging from about 6 months to 10 years were imaged using either Bioptigen or Cirrus OCT. Foveal cone structure was evaluated by assessing EZ integrity and ONL thickness.
RESULTS
A total of 470 OCT images were graded, 243 OD and 227 OS. The baseline distribution of EZ grades was highly symmetrical between eyes (P = 0.99) and there was no significant interocular difference in baseline ONL thickness (P = 0.12). The EZ grade remained unchanged over the follow-up period for 60 of 63 individuals. Foveal ONL thickness showed a clinically significant change in only 1 of the 61 individuals analyzed, although detailed adaptive optics imaging revealed no changes in cone density in this individual.
CONCLUSIONS
ACHM appears to be a generally stable condition, at least over the follow-up period assessed here. As cones are the cellular targets for emerging gene therapies, stable EZ and ONL thickness demonstrate therapeutic potential for ACHM, although other aspects of the visual system need to be considered when determining the best timing for therapeutic intervention.
Topics: Humans; Color Vision Defects; Tomography, Optical Coherence; Retinal Cone Photoreceptor Cells; Fovea Centralis; Retina
PubMed: 38587442
DOI: 10.1167/iovs.65.4.16 -
Journal of Neuro-ophthalmology : the... Jan 2024The clinical characteristics of patients with polymerase gamma (POLG) mutation-associated optic neuropathy remain incompletely characterized.
BACKGROUND
The clinical characteristics of patients with polymerase gamma (POLG) mutation-associated optic neuropathy remain incompletely characterized.
METHODS
We describe the clinical characteristics of 3 patients with POLG-associated optic neuropathy. We performed a literature review of optic neuropathy cases associated with POLG mutations and compared them with our cohort.
RESULTS
Many published cases of POLG-associated optic neuropathy in our literature review lacked details regarding severity of vision loss, visual field defects, and optical coherence tomography analysis. The clinical presentation of POLG mutations remains widely variable in age (from pediatric cases to adults) and associated systemic findings. All patients in our literature review presented with systemic symptoms, most commonly muscle weakness, ptosis, and ophthalmoplegia, whereas many young patients had severe systemic symptoms. In our case series, all 3 cases had isolated optic neuropathy affecting the papillomacular bundle, with signs such as reduced visual acuity and color vision, central visual field defects, temporal retinal nerve fiber layer loss with temporal optic disc pallor, and retinal ganglion cell complex loss. In addition, 2 of the 3 cases had added mitochondrial stressors in addition to the POLG mutation.
CONCLUSIONS
Clinicians should be aware that POLG mutations can present as isolated optic neuropathy primarily affecting the papillomacular bundle. With mitochondrial failure being the likely underlying pathogenic mechanism in POLG-associated optic neuropathy, helping affected patients eliminate mitochondrial stressors may be important in reducing the risk for progressive vision loss in this otherwise currently untreatable disorder.
PubMed: 38294884
DOI: 10.1097/WNO.0000000000002089