Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 37 for “"Fovea"”.
-
Spatial summation in the dark-adapted fovea
… of spatial summation in the dark-adapted fovea. Appearance reports were also monitored to investigate the relationship between detection and perception. Methods: 1) Absolute thresholds for small (~1' full width at half maximum – FWHM, and 27' diameter), brief (34 ms), monochromatic (550 …
-
A Study of the Accuracy of the Saccadic Eye Movement System as a Function of Target Distance, Duration and Direction.
… density of photoreceptors is located at the fovea, the best spatial resolution is obtained when the image of an object is focused upon the fovea.
-
The Effects of Target Velocity and Duration on Horizontal Smooth Pursuit Eye-Tracking in Normal Subjects, Rewarded and Non-Rewarded Schizophrenics.
… density of photoreceptors being located at the fovea. A perceptual correlate of this anatomical distribution is that visual acuity (a measure of spatial resolution) is greatest at the fovea. Accordingly, one function of eye movements is to acquire visual targets for foveal viewing.
-
Computer-assisted colour fundus image analysis
… two automatic retinal image analysis algorithms; fovea detection and artery-vein classification. The fovea, which lies within the macula region, is responsible for high resolution vision. Hence, presence of lesions or changes in the morphology of this region may be signs of pathologies such as …
-
Structural Integrity of Eyes Diagnosed with Amblyopia. The measurement of retinal structure in amblyopia using Optical Coherence Tomography.
… the visual pathway across the retina from the fovea, via the paramacular bundle to the optic disc, where peripapillary retinal nerve fibre thickness has been imaged and subjected to detailed measures along with optic disc size and shape. The study formed two phases, the first imaging the eyes …
-
Discharge Patterns of Brain Stem Neurons During Saccadic and Pursuit Tracking Eye Movements.
… so that the image of the object falls on the fovea, the retinal area with the greatest density of photoreceptors.
-
Multidimensional Approach to Comparative Avian Visual Systems
… into three types of retinal specializations: fovea, area, and visual streak, with the highest, intermediate, and lowest peak and peripheral ganglion cell densities, respectively. The implication is that foveate species may have more enhanced visual centers in the brain than non-foveate …
-
Tests of a Functional Account of the Abney Effect
… a wide range of wavelengths and between the fovea and periphery. Purity was varied by adding either a fixed spectrum or by varying the spectral bandwidth, using an Agile Light Source capable of generating arbitrary spectra. For both types of spectra, hue loci were approximated by the Gaussian …
-
Cortical location of saccadic and vergence oculomotor learning using fMRI
… direct the visual information of interest to the fovea, the area of the retina which has the highest density of photoreceptors, and the largest amount of cortical area. This research will study how two of the five eye movement systems utilize oculomotor learning. Saccadic eye movements are used to …
-
Descending premotor target tracking systems in flying insects
… of small moving objects across the dorsal fovea region of the eye which is fixated on prey during predatory pursuit, and are thought to constitute the commands necessary for actuating an interception flight path. TSDNs are characterised by their receptive fields, with responses of each TSDN …
-
Action Intention Modulates the Activity Pattern in Early Visual Areas
… and the occipital pole, corresponding to the fovea. During planning, univariate analysis did not reveal significant results so we used multi-voxel pattern analysis (MVPA) to decode action type and object orientation. Though objects were located in the periphery, we found a significant decoding …
-
Functional aspects of blur adaptation in human vision. A study of the mechanism of blur adaptation in human vision - its origin and scope evidenced using subjective and objective procedures.
… using subjective and objective methods. Parafoveal visual acuity measured under defocused conditions demonstrates that blur adaptation is not limited to the fovea. The presence of the adaptive mechanism in the parafovea also suggests that the neural compensation that takes places under …
-
Visual Enumeration: Subitizing and Its Nature
… 4 items can be quickly enumerated from an extrafovea display and be used in the following enumeration process when the display comes into fovea in the next fixation. While a valid peripheral preview facilitates enumeration speed, invalid preview information causes a penalty in both accuracy and …
-
Peripher induzierte Pulsation eines fovealen Nachbildes: Nachweis eines weitreichenden neuronalen Effektes
… Effekt der von der Netzhautperipherie auf die Fovea wirkt. Als Sonde verwende ich ein von einem Fotoblitz erzeugtes, foveales Nachbild. Ein solches Nachbild erscheint dunkel, wenn es vor einem hellen Hintergrund gesehen wird, und hell, wenn es vor einem dunklen Hintergrund gesehen wird. Wird …
-
Biomechanische Untersuchungen am Fesselgelenk (Articulatio metacarpophalangea) des Pferdes
… the trochlea, as well as the palmar edge of the fovea articularis show low bone density. Altough the lateral edges of the trochlea and the fovea articularis show a higher density. The method of split lines showed no definite preferential orientation of the collagen fibres in the subchondral bone …
-
Pre-Saccadic Modulation of the Visually Evoked Potential
… rapid eye movements that allow us to focus the fovea on different parts of our visual environment. Many psychophysical studies have shown that subjects can discriminate stimuli presented at the saccadic target better than at any other location before an eye movement is made. It is believed that …
-
Variation in wing area and prey detection volume of Rhinolophus Capensis in response to different climates
… clutter. HDC echolocators use an acoustic fovea and Doppler shift compensation to detect the fluttering wings of insect prey in dense vegetation. However, the flexibility of these pulses is limited by the bat's acoustic fovea. Wing shape and echolocation combined form an adaptive complex, …
-
Visual working memory supports perceptual stability across saccadic eye movements
… those features within a small region near the fovea. If this locating process succeeds, perceptual stability is maintained. The present study investigated directly whether perceptual stability does indeed rely on VWM. If it does, then perceived stability should be impaired when VWM is loaded …
-
An investigation of the relationship between the structure and function of the myopic eye. Correlating the optical, functional and structural aspects of ametropia in young adult humans.
… regression analyses were performed at the fovea and outermost retinal eccentricities common to all core experiments but revealed no strong relationship between the structure and function of the myopic eye. Finally, regarding asymmetry, the nasal and superior retinae were found to be longer …
Page 1 of 2