Search results for "visual"
showing 10 items of 7386 documents
Diurnal variations in visual performance for disposable contact lenses.
2013
The purpose of this study is to compare the visual performance provided by different daily disposable contact lenses and to analyze its variation over time.Visual performance was evaluated in terms of visual acuity (VA) and contrast sensitivity (CS) in 15 myopic subjects (-0.50 to -4.00 diopters) who had been previously fitted with each one of the following seven types of soft contact lenses: DAILIES TOTAL1 (Alcon, Forth Worth, TX), DAILIES AquaComfort Plus (Alcon), 1-DAY ACUVUE TruEye (JohnsonJohnson Vision Care, Jacksonville, FL), 1-DAY ACUVUE MOIST (JohnsonJohnson Vision Care), SofLens daily disposable (BauschLomb, Rochester, NY), Proclear 1 Day (CooperVision, Fairport, NY), and Clariti …
Application of a capsaicin rinse in the treatment of burning mouth syndrome
2010
Objective: To examine the efficacy of a new topical capsaicin presentation as an oral rinse in improving the symptoms of burning mouth syndrome (BMS). Study design: A prospective, double-blind, cross-over study was made of 30 patients with BMS. There were 7 dropouts; the final study series thus comprised 23 individuals. The patients were randomized to two groups: (A) capsaicin rinse (0.02%) or (B) placebo rinse, administered during one week. After a one-week washout period, the patients were then assigned to the opposite group. Burning discomfort was scored using a visual analog scale (VAS): in the morning before starting the treatment, in the afternoon on the first day of treatment, and at…
Dose escalating safety study of CNS 5161 HCl, a new neuronal glutamate receptor antagonist (NMDA) for the treatment of neuropathic pain
2007
What is already known about this subject • Despite encouraging effects of N-methyl-D-aspartate (NMDA) receptor antagonists in reducing neuropathic pain of different aetiologies, the clinical use of these agents has been limited by their mainly psychotropic side-effects. • In a recent study in healthy volunteers, CNS 5161, a novel noncompetetive NMDA receptor antagonist, was well tolerated up to a dosage of 2000 µg without psychotropic side-effects. • This is the first study to evaluate the maximal tolerated dosage of CNS 5161 and to gain experience about the analgesic effect of CNS 5161 in patients with different pain syndromes. What this study adds • In patients with neuropathic pain CNS 5…
Influence of vagus nerve stimulation on histamine-induced itching
2002
To investigate whether vagus nerve stimulation (VNS) reduces pruritus in humans.Recently, it has been shown that VNS has antinociceptive and antidepressant effects in humans.Eleven patients were investigated before (baseline) and during chronic VNS treatment. The experiments were performed at two different stimulation intensities: 2 to 5 days after implantation at a low stimulation intensity (mean intensity 0.7 +/- 0.2 mA, second session) and after 8 to 14 weeks of VNS therapy (mean intensity 1.4 +/- 0.3 mA, third session). Twelve healthy age- and sex-matched subjects were investigated using the same experimental protocol. Itch was induced by histamine-iontophoresis and quantified on a visu…
The human brain processes visual changes that are not cued by attended auditory stimulation.
2004
Event-related potentials (ERPs) to visual stimuli were recorded from the scalp of eight adult humans performing a task in which they counted vowels from a heard story. In the oddball condition, a repeated (standard) light bar of 50 ms in duration was rarely (P = 0.1) replaced by a (deviant) one differing in orientation from the standard. In the control condition, standards were simply omitted from the series and only (alone-) deviants retained. In both conditions, visual stimuli were asynchronous with auditory-task-relevant stimuli. ERPs to deviants significantly differed in amplitude from those to standards in the midline electrodes centrally, parietally and occipitally at 160-200 ms from …
Measuring Perceived Ceiling Height in a Visual Comparison Task
2017
When judging interior space, a dark ceiling is judged to be lower than a light ceiling. The method of metric judgments (e.g., on a centimetre scale) that has typically been used in such tasks may reflect a genuine perceptual effect or it may reflect a cognitively mediated impression. We employed a height-matching method in which perceived ceiling height had to be matched with an adjustable pillar, thus obtaining psychometric functions that allowed for an estimation of the point of subjective equality (PSE) and the difference limen (DL). The height-matching method developed in this paper allows for a direct visual match and does not require metric judgment. It has the added advantage of pro…
Anatomical correlates of visual and tactile extinction in humans: a clinical CT scan study.
1994
The anatomical correlates of tactile and visual extinction with double simultaneous stimulation were investigated in a series of 159 patients with right brain damage caused by stroke. Forty six patients showed extinction (22 tactile, 14 visual, 10 tactile and visual). Over 50% of the patients with extinction had deep lesions, which were found in about 25% of the patients with visuospatial neglect not associated with extinction. In the patients with extinction and cortico-subcortical damage the paraventricular occipital white matter and the dorsolateral frontal cortex were most often involved. By contrast, when neglect was also present, the lesions clustered in the inferior parietal lobule. …
The effects of social pressure and emotional expression on the cone of gaze in patients with social anxiety disorder
2016
Abstract Background and objectives Patients with social anxiety disorder suffer from pronounced fears in social situations. As gaze perception is crucial in these situations, we examined which factors influence the range of gaze directions where mutual gaze is experienced (the cone of gaze). Methods The social stimulus was modified by changing the number of people (heads) present and the emotional expression of their faces. Participants completed a psychophysical task, in which they had to adjust the eyes of a virtual head to gaze at the edge of the range where mutual eye-contact was experienced. Results The number of heads affected the width of the gaze cone: the more heads, the wider the …
Quantifying the Wollaston Illusion
2020
In the early 19th century, William H. Wollaston impressed the Royal Society of London with engravings of portraits. He manipulated facial features, such as the nose, and thereby dramatically changed the perceived gaze direction, although the eye region with iris and eye socket had remained unaltered. This Wollaston illusion has been replicated numerous times but never with the original stimuli. We took the eyes (pupil and iris) from Wollaston’s most prominent engraving and measured their perceived gaze direction in an analog fashion. We then systematically added facial features (eye socket, eyebrows, nose, skull, and hair). These features had the power to divert perceived gaze direction by…
Effect of musical expertise on visuospatial abilities: evidence from reaction times and mental imagery.
2003
Abstract Recently, the relationship between music and nonmusical cognitive abilities has been highly debated. It has been documented that formal music training would improve verbal, mathematical or visuospatial performance in children. In the experiments described here, we tested if visual perception and imagery abilities were enhanced in adult musicians compared with nonmusicians. In our main experiment, we measured reaction times of subjects who had to detect on which side of a horizontal or a vertical line a target dot was flashed. In the “imagery” condition the reference line disappeared before the target dot was presented. In order to accomplish the task, subjects had to keep a mental …