Search results for "Sensory System"
showing 10 items of 1266 documents
Prevalence of cataract after collagen copolymer phakic intraocular lens implantation for myopia, hyperopia, and astigmatism
2015
Purpose To evaluate the prevalence of cataract after Implantable Collamer Lens phakic intraocular lens (pIOL) implantation with different models at different ages and for different refractive powers. Setting Fernandez-Vega Ophthalmological Institute, Oviedo, Spain. Design Retrospective nonrandomized clinical study. Methods The pIOL (models V4, V4b, or V4c) was implanted in all cases. Results The study included 3420 eyes (1898 patients). The mean patient age at surgery was 31.2 years ± 6.4 (SD) (range 18 to 50 years) and the mean spherical refractive error, −7.27 ± 5.24 diopters (D) (range −26.5 to 12.5 D). Twenty-one eyes (0.61%) of 15 patients had pIOL explantation (all model V4) because c…
Collagen copolymer posterior chamber phakic intraocular lens supported by the ciliary sulcus to treat myopia: One-year follow-up
2014
Purpose To evaluate the predictability, stability, safety, and efficacy of Visian V4b Implantable Collamer Lens phakic intraocular lens (pIOL) implantation to treat varying degrees of myopia. Setting Fernandez-Vega Ophthalmological Institute, Oviedo, Spain. Design Prospective nonrandomized clinical study. Methods The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, pIOL vault, and adverse effects were evaluated 12 months postoperatively. Results The study enrolled 121 eyes (68 patients). The mean spherical equivalent decreased from −8.61 diopters (D) ± 3.41 (SD) (range −18.75 to −2.25 D) preoperatively to −0.18 ± 0.29 D (range −1.25 to 0.50 D) 12 months postoper…
Iris-fixated toric phakic intraocular lens for myopic astigmatism
2011
Purpose To evaluate the efficacy, predictability, safety, stability, and complications of the Artiflex toric iris-fixated phakic intraocular lens (pIOL) for myopic astigmatism. Setting Private practice surgery centers, Valencia and Terrassa, Spain. Design Cohort study. Methods At 12 months, refraction, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, complications, pIOL misalignment, and endothelial cell count (ECC) were evaluated. Indices of success and misalignment were calculated using vector analysis. Results The study enrolled 42 eyes in 25 patients aged 21 to 39 years. The mean spherical equivalent decreased from −8.85 diopters (D) ± 2.71 (SD) to −0.37 ± 0.46 D, with …
Dipole Source Analyses of Early Median Nerve SEP Components Obtained From Subdural Grid Recordings
2010
The median nerve N20 and P22 SEP components constitute the initial response of the primary somatosensory cortex to somatosensory stimulation of the upper extremity. Knowledge of the underlying generators is important both for basic understanding of the initial sequence of cortical activation and to identify landmarks for eloquent areas to spare in resection planning of cortex in epilepsy surgery. We now set out to localize the N20 and P22 using subdural grid recording with special emphasis on the question of the origin of P22: Brodmann area 4 versus area 1. Electroencephalographic dipole source analysis of the N20 and P22 responses obtained from subdural grids over the primary somatosensor…
Cutaneous Painful Laser Stimuli Evoke Responses Recorded Directly From Primary Somatosensory Cortex in Awake Humans
2004
Negative and positive laser evoked potential (LEP) peaks (N2*, P2**) were simultaneously recorded from the primary somatosensory (SI), parasylvian, and medial frontal (MF: anterior cingulate and supplementary motor area) cortical surfaces through subdural electrodes implanted for the surgical treatment of intractable epilepsy. Distribution of the LEP N2*and P2**peaks was estimated to be in cortical areas (SI, parasylvian, and MF) identified by anatomic criteria, by their response to innocuous vibratory stimulation of a finger (v-SEP), and to electrical stimulation of the median nerve (e-SEP). The maximum of the LEP N2*peak was located on the CS, medial (dorsal) to the finger motor area, as …
Selection of odorants for memory tests on the basis of familiarity, perceived complexity, pleasantness, similarity and identification
2002
In a procedure for the selection of two equivalent sets of familiar and two equivalent sets of unfamiliar odours for use in odour memory studies, 24 naive subjects were first asked to rate the familiarity, perceived complexity and pleasantness of 54 a priori unfamiliar odours and 57 a priori familiar odours and to identify the latter. After selection of the 40 most familiar and the 40 least familiar odours, the subjects sorted each of these two sets into groups of similar odours. Their results were analysed by multidimensional scaling and cluster analysis and each set was divided into two recognition sets that had the same degree of similarity between target and distractor odours and that h…
On-eye optical quality of daily disposable contact lenses for different wearing times
2012
Purpose To quantify the optical quality of various daily disposable contact lenses in vivo and to ascertain its variation in terms of wearing time by means of objective non-invasive determination of wavefront patterns. Methods The crx1 adaptive-optics system was used to measure the wavefront aberrations in 15 myopic eyes before and at 2-h intervals after contact lens fitting, over a 12-h wearing period. Seven types of contact lenses having different material, water content and lens design were evaluated in this study: Dailies Total1, Dailies AquaComfort Plus, Proclear 1 Day, 1-Day Acuvue TruEye, 1-Day Acuvue moist, SofLens daily disposable and Clariti 1-Day. The aberration data were analyse…
Effects of emotional picture viewing on voluntary eye blinks
2014
Eyeblinks, whether reflexive or voluntary, play an important role in protecting our vision. When viewing pictures, reflexive eyeblinks are known to be modulated by the emotional state induced thereby. More specifically, the hedonic valence (unpleasantness-pleasantness) induced by the picture has been shown to have a linear relationship with the amplitude of a startle blink elicited during picture viewing. This effect has been attributed to congruence between an ongoing state and task demands: an unpleasant emotional state is assumed to bias our attention towards potentially harmful stimuli, such as startle tones. However, recent research suggests that the valence-specific modulation may not…
Factor analysis and reliability of the Movement Imagery Questionnaire.
1994
The purpose of this work was to analyze the factor structure, estimate reliability of the Movement Imagery Questionnaire of Hall and Pongrac, and examine differences between men and women on factor scores. The results for 63 men and 47 women supported the bifactorial structure and reliability of this self-report and its adequacy in comparisons of visual and kinesthetic imagery scores.
Reduced oscillatory gamma-band responses in unmedicated schizophrenic patients indicate impaired frontal network processing
2004
Abstract Objective Integration of sensory information by cortical network binding appears to be crucially involved in target detection. Studies in schizophrenia using functional and diffusion tensor neuroimaging, event-related potentials and EEG coherence indicate an impairment of cortical network coupling in this disorder. Previous electrophysiological investigations in animals and humans suggested that gamma activity (oscillations at around 40 Hz) is essential for cortical network binding. Studies in medicated schizophrenia provide evidence for a reduced gamma activity in the context of auditory stimulus processing. This is the first investigation of oscillatory activations in the gamma-b…