Search results for "structures"
showing 10 items of 4815 documents
Self-compassion as an emotion regulation strategy in major depressive disorder
2013
Cognitive reappraisal and acceptance are two presumably adaptive emotion regulation strategies in depression. More recently, self-compassion has been discussed as another potentially effective strategy for coping with depression. In the present study, we compared the effectiveness of self-compassion with a waiting condition, reappraisal, and acceptance in a clinically depressed sample, and tested the hypothesis that the intensity of depressed mood would moderate the differential efficacy of these strategies. In an experimental design, we induced depressed mood at four points in time in 48 participants meeting criteria for major depressive disorder. After each mood induction, participants we…
Dependence of Perceived Purity of a Chromatic Stimulus on Saturation Adaptation
2012
Background and Objective. The purpose of sensory adaptation of the visual system is to adjust sensitivity of the photoreceptors to optimize the dynamic range of response of the visual system. It has been shown in numerous research papers that chromatic adaptation influences both color appearance and color discrimination. However, there are almost no studies in which the influence of chromatic adaptation on perceived purity has been investigated. Therefore, the aim of this study was to investigate how chromatic adaptation to stimuli with certain saturation influences perceived purity of test stimuli with the same hue but different saturation. Material and Methods. As the stimuli were modulat…
Mutational screening of the USH2A gene in Spanish USH patients reveals 23 novel pathogenic mutations
2011
Abstract Background Usher Syndrome type II (USH2) is an autosomal recessive disorder, characterized by moderate to severe hearing impairment and retinitis pigmentosa (RP). Among the three genes implicated, mutations in the USH2A gene account for 74-90% of the USH2 cases. Methods To identify the genetic cause of the disease and determine the frequency of USH2A mutations in a cohort of 88 unrelated USH Spanish patients, we carried out a mutation screening of the 72 coding exons of this gene by direct sequencing. Moreover, we performed functional minigene studies for those changes that were predicted to affect splicing. Results As a result, a total of 144 DNA sequence variants were identified.…
Comparison of short-term light disturbance, optical and visual performance outcomes between a myopia control contact lens and a single-vision contact…
2020
Purpose To compare the optical and visual performance of a dual-focus (DF) contact lens used for myopia control with a single-vision (SV) contact lens of the same material. Methods A randomised, double-masked crossover study. Twenty-eight healthy, myopic volunteers between 18 and 32 years of age (23.49 +/- 4.07 years) participated in this study. The sensory dominant eye for distance vision was determined. Refraction, best-corrected visual acuity (VA) and aberrations for 3 mm and 5 mm pupil diameters were quantified without a contact lens in situ. Subjects were fitted with two contact lens designs: DF and SV, both made of omafilcon A material. The Quality of Vision (QoV) questionnaire, over-…
The hippocampus is required for short-term topographical memory in humans.
2007
The hippocampus plays a crucial role within the neural systems for long-term memory, but little if any role in the short-term retention of some types of stimuli. Nonetheless, the hippocampus may be specialized for allocentric topographical processing, which impacts on short-term memory or even perception. To investigate this we developed performance-matched tests of perception (match-to-sample) and short-term memory (2 s delayed-match-to-sample) for the topography and for the nonspatial aspects of visual scenes. Four patients with focal hippocampal damage and one with more extensive damage, including right parahippocampal gyrus, were tested. All five patients showed impaired topographical m…
Primary motor area contribution to attentional reorienting after distraction
2008
The anatomical structures involved in distraction-related processing in the auditory domain were investigated using magnetoencephalography. Participants performed a duration-discrimination task on a sequence of 200 and 400 ms long tones. Infrequent (12%) task-irrelevant pitch changes resulted in slower discriminative responses and more errors. Event-related potentials to these changes show an increased N1, a mismatch negativity, a P3a, and a reorienting negativity. The event-related magnetic fields revealed focal activities in superior and medial temporal areas in the N1/mismatch negativity time range. No significant activity was found in the P3a interval. In the reorienting negativity inte…
Parafoveal versus foveal N400s dissociate spreading activation from contextual fit.
2009
Using concurrent electroencephalogram and eye movement measures to track natural reading, this study shows that N400 effects reflecting predictability are dissociable from those owing to spreading activation. In comparing predicted sentence endings with related and unrelated unpredicted endings in antonym constructions ('the opposite of black is white/yellow/nice'), fixation-related potentials at the critical word revealed a predictability-based N400 effect (unpredicted vs. predicted words). By contrast, event-related potentials time locked to the last fixation before the critical word showed an N400 only for the nonrelated unpredicted condition (nice). This effect is attributed to a parafo…
Impairments in top down attentional processes in right parietal patients: Paradoxical functional facilitation in visual search
2014
AbstractIt is well known that the right posterior parietal cortex (PPC) is involved in attentional processes, including binding features. It remains unclear whether PPC is implicated in top-down and/or bottom-up components of attention. We aim to clarify this by comparing performance of seven PPC patients and healthy controls (HC) in a visual search task involving a conflict between top-down and bottom-up processes. This task requires essentially a bottom-up feature search. However, top-down attention triggers feature binding for object recognition, designed to be irrelevant but interfering to the task. This results in top-down interference, prolonging the search reaction time. This interfe…
Ranibizumab for Branch Retinal Vein Occlusion Associated Macular Edema Study (RABAMES): six-month results of a prospective randomized clinical trial
2014
Purpose To compare standard-of-care grid laser photocoagulation versus intravitreal ranibizumab (IVR) versus a combination of both in the treatment of chronic (>3 months) macular oedema secondary to branch retinal vein occlusion. Methods Prospective, randomized, multicentre clinical trial. Thirty patients with a best-corrected visual acuity (BCVA) between 20/320 and 20/40 were randomized 1:1:1 to receive grid laser or three monthly injections of 0.5 mg IVR or both followed by 3 months of observation. Results Mean change from baseline BCVA at month 6 was +2 letters [laser; 0.04 logMAR, 95% confidence interval (−0.17; 0.25)], +17 letters [IVR; 0.34 (0.19; 0.5)] and +6 letters [combination; 0.…
Aqueous Humor Levels of Vascular Endothelial Growth Factor in Retinitis Pigmentosa
2008
PURPOSE To determine the level of vascular endothelial growth factor A (VEGF-A) in aqueous humors of patients with retinitis pigmentosa (RP). METHODS A prospective, comparative control study. Aqueous humor was collected from 16 eyes of 16 patients with RP. The level of VEGF-A was determined with a commercially available enzyme-linked immunosorbent assay kit. The control group comprised 16 aqueous samples from 16 patients about to undergo cataract surgery and without any other ocular or systemic diseases. RESULTS The concentration of VEGF-A in aqueous humor was markedly lower in patients with RP than in control subjects (Mann-Whitney U test, P < 0.001). The level of VEGF-A was 94.9 +/- 99.8 …