Search results for "Blindness"
showing 10 items of 85 documents
Analysis of the human a-wave ERG component
2006
The a-wave is one of the main issues of research in the field of ocular electrophysiology, since it is strictly connected with early photoreceptoral activities. The present study proposes mathematical methods that analyse this component in human subjects, and supports experimental evidence relating to possible correlations among the responses of photoreceptoral units under a light stimulus. The investigation is organized in two parts: the first part concerns the onset and the initial slope, up to the first minimum (about 10-15 ms), the second part deals with the main portion of the wave, up to about 30 ms. In both cases, the a-waves, recorded at various levels of luminance, have been fitted…
Synaesthesia through the blind man’s eyes
2014
International audience
A Tunable Digital Ishihara Plate for Pre-School Aged Children
2016
Colors play a fundamental role for children, both in the everyday life and in education. They recognize the surrounding world, and play games making a large use of colors. They learn letters and numbers by means of colors. As a consequence, early diagnosis of color blindness is an crucial to support an individual affected by this visual perception alteration at the initial phase of his/her life. The diagnosis of red-green color deficiencies (protanopia or deuteranopia) is commonly accomplished by means of the Ishihara test, which consists of plates showing dots with different sizes where some of them compose numbers within a gamut of colors while the ones composing the background have diffe…
Congruence and placement in sponsorship: An eye-tracking application
2019
Sporting events can be announced using sports posters and by disseminating advertisements on the internet, on the street and in print media. But until now, no prior research has measured the effectiveness of sponsorship in sporting event posters. This study uses eye tracking to measure the effectiveness of sporting event posters and proposes considering the level of the viewer's attention as an indicator. This research involves a factorial experiment based on the following variables: congruence, the number of sponsors, and placement of the sponsor's advertisement in a sporting event poster. The results indicate that sponsors positioned in the poster's area of action receive more attention. …
Next-generation sequencing confirms the implication of SLC24A1 in autosomal-recessive congenital stationary night blindness.
2015
Congenital stationary night blindness (CSNB) is a clinically and genetically heterogeneous retinal disorder which represents rod photoreceptor dysfunction or signal transmission defect from photoreceptors to adjacent bipolar cells. Patients displaying photoreceptor dysfunction show a Riggs-electroretinogram (ERG) while patients with a signal transmission defect show a Schubert-Bornschein ERG. The latter group is subdivided into complete or incomplete (ic) CSNB. Only few CSNB cases with Riggs-ERG and only one family with a disease-causing variant in SLC24A1 have been reported. Whole-exome sequencing (WES) in a previously diagnosed icCSNB patient identified a homozygous nonsense variant in SL…
Branch Retinal Vein Occlusion Followed by Central Retinal Artery Occlusion in Churg-Strauss Syndrome: Unusual Ocular Manifestations in Allergic Granu…
2009
Purpose To describe a rare branch retinal vein occlusion (BRVO) followed by central retinal artery occlusion (CRAO) in a patient with Churg-Strauss syndrome (CSS). Methods A 55-year-old man with a not yet diagnosed CSS developed a BRVO in the left eye and 1 year later a CRAO with painless and acute vision loss in the same eye. Medical history included bronchial asthma, history of allergy, eosinophilic pneumonia, bilateral pleuric and pericardial effusion, hypereosinophilia, and purpuric vasculitis. Results CRAO in the left eye was diagnosed by retinal whitening and a cherry red spot with coexisting old BRVO evidenced by previous laser photocoagulation. Corticosteroids and cyclophosphamide t…
Further delineation of eye manifestations in homozygous 15q13.3 microdeletions including TRPM1: a differential diagnosis of ceroid lipofuscinosis.
2014
The 15q13.3 heterozygous microdeletion is a fairly common microdeletion syndrome with marked clinical variability and incomplete penetrance. The average size of the deletion, which comprises six genes including CHRNA7, is 1.5 Mb. CHRNA7 has been identified as the gene responsible for the neurological phenotype in this microdeletion syndrome. Only seven patients with a homozygous microdeletion that includes at least CHRNA7, and is inherited from both parents have been described in the literature. The aim of this study was to further describe the distinctive eye manifestations from the analysis in the three French patients diagnosed with the classical 1.5 Mb homozygous microdeletion. Patients…
Early-blind individuals show impaired performance in wine odor categorization
2018
International audience; Blind individuals display superior sensory abilities in other modalities, yet results remain contradictory regarding their performance on olfactory tasks. Using complex ecological olfactory tasks, we evaluated the impact of blindness on olfactory performance. We tested 12 early-blind individuals (M = 49, SD = 13.09) and 12 sighted controls (M = 49, SD = 14.31) who were all blindfolded. Based solely on the wine odors, participants evaluated 24 pairs of wine and determined if both samples belonged to the same category (red wine, white wine, or rosé wine) or not (odor categorization), and if so, whether they were identical or not (odor differentiation). Then, they had t…
Implicit binding of facial features during change blindness
2014
Change blindness refers to the inability to detect visual changes if introduced together with an eye-movement, blink, flash of light, or with distracting stimuli. Evidence of implicit detection of changed visual features during change blindness has been reported in a number of studies using both behavioral and neurophysiological measurements. However, it is not known whether implicit detection occurs only at the level of single features or whether complex organizations of features can be implicitly detected as well. We tested this in adult humans using intact and scrambled versions of schematic faces as stimuli in a change blindness paradigm while recording event-related potentials (ERPs). …
Effects of chemical and surgical ganglionectomy on electrical activity of the pineal gland of male rats.
1986
In order to elucidate further the role of sympathetic innervation for pineal function, the influence of sympathectomy on the spontaneous electrical activity of single cells in the pineal gland of adult male rats was investigated. Extracellular single-unit recordings were made during nighttime in the pineal gland of urethane-anesthetized, blinded adult male rats that had been treated neonatally with 6-hydroxydopamine, or that were ganglionectomized either during, or 12-16 h or 36-40 h, prior to the recording experiment. These experiments revealed that the excitatory influence of the sympathetic system on pineal nocturnal electrical activity can be abolished by either chemical sympathectomy o…