BACKGROUND: The peak sports performance of elite athletes is the result of talent and long-term, systematic training. Only minor differences among athletes determine the results in sport today. In selected sports events, stereoscopic vision has a fundamental influence on the executed sports performance. METHODS: The quality of stereopsis was determined in 2 groups of top-level athletes at the age of 16-18 years (21 pole vaulters and high jumpers and 25 swimmers) and in a control group of 25 nonathletes in the same age category. Two measured parameters (results and time in the stereopsis test) were compared among the studied groups. To determine the quality of stereopsis, the "Fly-S Stereo Acuity Test with LEA Symbols" field stereoacuity test was used. RESULTS: The average level of stereopsis in the pole vaulters and high jumpers reached the value of 9.9 (max. 10), and the average time needed for performing the stereopsis test was 11.6 seconds. The group of swimmers and control group showed worse results in both measured parameters (the average level of stereopsis: 9.4, resp. 9.1, the average test time: 30.0 seconds, resp. 36.1 seconds). A significant difference between the group of pole vaulters and high jumpers and swimmers was confirmed in both monitored parameters. No significant differences were found between the group of swimmers and nonathletes. CONCLUSIONS: On the basis of the stereopsis test results, we can say that top-level pole vaulters and high jumpers have a high quality of stereopsis and very fast identification and decision-making abilities in spatial orientation.
- MeSH
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- nadání MeSH
- percepce hloubky * MeSH
- sportovci * MeSH
- sportovní výkon MeSH
- zraková ostrost MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
UNLABELLED: Main purpose of this study was to evaluate effect of aniseikonia on the stereo vision. We had together 90 subjects without eye pathology with or without habitual correction. Five of them were excluded due to important anisometropia or bad visual acuity (V < 0.5 on worse eye). All 85 subjects every in 4 cases (without size lens, with size lens on OD 1, 3 and 5 %) undergone measuring of their stereoscopy parallax. This was evaluated by Random dot stereo test. The level for stereoscopy vision was set bellow 60 arc seconds. This criterion was not achieved naturally by 6 subjects, so final number of all cases was 316 (100 %). As a whole 48 subjects (15.2 %) fail after using the test with size lens on OD 1, 3 or 5 %. All 268 cases (84.8 %) had not impaired stereoscopy parallax with size lens over chosen critical level. KEY WORDS: size lens, anisometropia, aniseikonia, heterophoria, stereoscopy vision.
- MeSH
- aniseikonie patofyziologie MeSH
- dospělí MeSH
- lidé MeSH
- percepce hloubky fyziologie MeSH
- zraková ostrost fyziologie MeSH
- zrakové testy MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
The main purpose of this study was to determine the effect of the depth description levels required in experimental tasks on visual space perception. Six observers assessed the locations of 11 posts by determining a distance ranking order, comparing the distances between posts with a reference unit, and estimating the absolute distances between the posts. The experiments were performed in an open outdoor field under normal daylight conditions with posts at distances ranging from 2 to 12 m. To directly assess and compare the observers' perceptual performance in all three phases of the experiment, the raw data were transformed to common measurement levels. A pairwise comparison analysis provided nonmetric information regarding the observers' relative distance judgments, and a multidimensional-scaling procedure provided metric information regarding the relationship between a perceived spatial layout and the layout of the actual scene. The common finding in all of the analyses was that the precision and consistency of the observers' ordinal distance judgments were greater than those of their ratio distance judgments, which were, in turn, greater than the precision and consistency of their absolute-magnitude distance judgments. Our findings raise questions regarding the ecological validity of standard experimental tasks.
- MeSH
- lidé MeSH
- mínění MeSH
- percepce vzdálenosti * MeSH
- vnímání prostoru * MeSH
- zraková percepce * MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
People confined to a closed space live in a visual environment that differs from a natural open-space environment in several respects. The view is restricted to no more than a few meters, and nearby objects cannot be perceived relative to the position of a horizon. Thus, one might expect to find changes in visual space perception as a consequence of the prolonged experience of confinement. The subjects in our experimental study were participants of the Mars-500 project and spent nearly a year and a half isolated from the outside world during a simulated mission to Mars. The participants were presented with a battery of computer-based psychophysical tests examining their performance on various 3-D perception tasks, and we monitored changes in their perceptual performance throughout their confinement. Contrary to our expectations, no serious effect of the confinement on the crewmembers' 3-D perception was observed in any experiment. Several interpretations of these findings are discussed, including the possibilities that (1) the crewmembers' 3-D perception really did not change significantly, (2) changes in 3-D perception were manifested in the precision rather than the accuracy of perceptual judgments, and/or (3) the experimental conditions and the group sample were problematic.
- MeSH
- bydlení klasifikace MeSH
- dospělí MeSH
- kosmický let * MeSH
- kosmonauti psychologie MeSH
- lidé MeSH
- Mars MeSH
- mínění fyziologie MeSH
- percepce vzdálenosti fyziologie MeSH
- psychický stres patofyziologie MeSH
- regresní analýza MeSH
- sociální izolace psychologie MeSH
- vnímání prostoru fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- klinické zkoušky MeSH
- práce podpořená grantem MeSH
PURPOSE: To evaluate refractive and visual parameters related to distance, intermediate, and near vision after cataract surgery and the optical quality of a new diffractive trifocal intraocular lens (IOL). SETTING: Vissum Instituto Oftalmologico de Alicante, Alicante, Spain. DESIGN: Case series. METHODS: Patients had bilateral refractive lens exchange and multifocal diffractive IOL (AT Lisa tri 839 MP) implantation. A complete ophthalmology examination was performed preoperatively and postoperatively. The follow-up was 6 months. The main outcome measures were uncorrected distance (UDVA) and corrected distance (CDVA), intermediate, and near visual acuities; keratometry; manifest refraction; and aberrations (total, corneal, internal). RESULTS: The study comprised 60 eyes of 30 patients (mean age 57.9 years ± 7.8 [SD]; range 42 to 76 years). There was significant improvement in UDVA, uncorrected intermediate visual acuity, uncorrected near visual acuity, CDVA, and distance-corrected intermediate and near visual acuity. The postoperative refractive status was within the range of +1.00 to -1.00 diopter. Total internal aberrations decreased significantly (P<.001). CONCLUSIONS: The trifocal IOL improved near, intermediate, and distance vision in presbyopic patients. The use of 3 foci provided significant intermediate visual results without sacrificing near or distance vision.
- MeSH
- aberometrie MeSH
- citlivost na kontrast fyziologie MeSH
- dospělí MeSH
- fakoemulzifikace * MeSH
- implantace nitrooční čočky * MeSH
- lidé středního věku MeSH
- lidé MeSH
- nitrooční čočky * MeSH
- percepce hloubky fyziologie MeSH
- protézy - design MeSH
- pseudofakie patofyziologie MeSH
- refrakce oka fyziologie MeSH
- rohovková topografie MeSH
- senioři MeSH
- spokojenost pacientů MeSH
- výsledek terapie MeSH
- zraková ostrost fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
The informational content in the location-specific discharge of rat hippocampal cells is usually quantified by an average for the entire behaviorally accessible space. In contrast to such "global" information measures, we consider here information that can be obtained from "local" spike counts at each position. The properties of these local information measures are first illustrated using simulated data with predetermined distributions of location-specific spike counts. Next, place cell recordings from rats foraging in a cylindrical arena with two cue cards on its walls are analyzed; time windows as short as 100 ms were used to accumulate spike counts in locations. We show that information at the centers of firing fields is higher for fields nearer to the cues. Neither firing rates or "global" information measures detected differences between fields near and far from the cues. Thus, analyses of the location-specific information provides a new valuable tool for studying the location-specific activity of rat hippocampal cells. Generalizations of location-specific information can be used to investigate place cell responses to other factors such as running speed or the state of the hippocampal EEG in addition to current position.
- MeSH
- akční potenciály fyziologie MeSH
- časové faktory MeSH
- elektrofyziologie MeSH
- hipokampus cytologie MeSH
- krysa rodu Rattus MeSH
- modely neurologické MeSH
- neparametrická statistika MeSH
- neurologie metody MeSH
- neurony fyziologie MeSH
- percepce vzdálenosti MeSH
- počítačová simulace MeSH
- podněty MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, P.H.S. MeSH
- srovnávací studie MeSH
The possibility that rats can navigate in the Morris water maze by reducing the difference between the memorized platform scene and the current sensory input was tested in nine blind rats. A computerized videosystem monitored the rats' movements in the pool and converted the rat-target distance into tones the frequency of which increased in 64 equal steps from 120 Hz at 128 cm to 7680 Hz at 0 cm. During 15 days of training to find a fixed platform position from different starting points (12 trials per day) average escape latencies decreased from 39.0 to 25.4 s. The performance significantly deteriorated when the acoustic distance signalization was omitted and/or when the target position was changed form trial to trial. It is concluded that blind rats solved the task by simultaneously employing search strategy based on position responses, mapping using acoustic background beacons, and distance reduction navigation. It is argued that the various strategies are additive and that their relative significance depends of the conditions of the experiment.
- MeSH
- akustická stimulace MeSH
- automatizované zpracování dat MeSH
- krysa rodu Rattus MeSH
- orientace fyziologie MeSH
- percepce vzdálenosti fyziologie MeSH
- slepota patofyziologie MeSH
- sluchová dráha fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Hemispheric asymmetries in different perceptual functions have been tested using the method of lateral presentation of stimuli i.e. in the left or right visual field. The first two experiments showed the right hemisphere advantage in the accuracy of detection of stereoscopic depth and in the strength of the tilt after-effect, i.e. in such phenomena which seem to be produced in the striate cortex. The third experiment, in which evoked potentials from point 01 and 02 during face perception were recorded, revealed the existence of right hemisphere superiority as early as 150 ms after stimulus presentation. These results indicate that the two hemispheres can already differ in their functions at the sensory level of processing.
Functional decortication induced by cortical spreading depression (CSD) was used to estimate the significance of cerebral cortex for swimming and depth avoidance in arts. In the swimming test (5 gr sinkers, 36 degrees C water) the median swimming time was reduced from greater 120 minutes in the controls to 16 minutes in the bilaterally depressed rats. Depth avoidance in the physical and visual cliff situation (6 cm to the shallow and 48 cm to the deep surface) was unimpaired by unilateral CSF but was abolished by bilateral CSD. Combination of monocular occlusion with ipsilateral CSD deteriorated the visual cliff test but not the physical cliff behaviour. Functional decortication increased descent latencies and decreased the explaration rate in both tests. It is concluded that cerebral cortex plays an important role in the regulation of unlearned, innate activities with the overall behaviour of the organism.
- MeSH
- časové faktory MeSH
- evokované potenciály MeSH
- lidé MeSH
- percepce hloubky fyziologie MeSH
- světelná stimulace MeSH
- týlní lalok fyziologie MeSH
- vnímání tvaru fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
