WorldCat Identities

Fahle, Manfred

Overview
Works: 37 works in 78 publications in 2 languages and 2,192 library holdings
Genres: Methods (Music) 
Roles: Author, Other, Editor
Classifications: QP408, 612.82
Publication Timeline
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Most widely held works by Manfred Fahle
Perceptual learning by Manfred Fahle( Book )

12 editions published between 2002 and 2016 in English and Undetermined and held by 314 WorldCat member libraries worldwide

Perceptual learning is the specific and relatively permanent modification of perception and behavior following sensory experience. It encompasses parts of the learning process that are independent from conscious forms of learning and involve structural and/or functional changes in primary sensory cortices. A familiar example is the treatment for a "lazy" or crossed eye. Covering the good eye causes gradual improvement in the weaker eye's cortical representations. If the good eye is patched too long, however, it learns to see less acutely. This book presents advances made in the last decade in this rapidly growing field. The first part examines neuronal changes caused by lesions or external influences. It discusses the effects of these changes on behavior and the extent to which plasticity in sensory systems is possible. Taking a broader view, the second part looks at how more conscious or systemic stimuli cause cortical changes. Clinical trials in which subjects are taught to recognize visual and auditory stimuli demonstrate the relationship between perceptual and cognitive learning. The final sections offer general models of perceptual learning and discuss the future of the field
The neuropsychology of vision( Book )

12 editions published in 2003 in English and held by 211 WorldCat member libraries worldwide

Describes a range of exciting new approaches to neuropsychological investigation and provides a broad overview of visual neuropsychology. The book starts by examining the neural basis of perception - presenting important new research using single-unit recordings. It then considers disturbances of visual perception such a agnosia, neglect, blindsight, and achromatopsia, describing what we now know about recovery and rehabilitation from cerebral visual disorders. Throughout, the book refers to new and adapted techniques for measuring brain activity, including multi-unit sum potential recording, fMRI, and transranial magnetic-stimulation. With contributions from leading scientists in the vision sciences, it provides a state-of-the-art review of the topic
Binokulares Einfachsehen : Zur Bedeutung von Konturendominanz und binokularem Wettstreit by Manfred Fahle( )

6 editions published in 1981 in German and Undetermined and held by 21 WorldCat member libraries worldwide

Sinnesphysiologie der "Überauflösung" : Wahrnehmung jenseits des Photorezeptoren-Durchmessers by Manfred Fahle( Book )

2 editions published in 1991 in German and held by 15 WorldCat member libraries worldwide

A model for rivalry between cognitive contours by Manfred Fahle( Book )

3 editions published in 1990 in English and held by 5 WorldCat member libraries worldwide

This report describes research done within the Artificial Intelligence Laboratory and the Center for Biological Information Processing (Whitaker College) at the Massachusetts Institute of Technology E25-201 Cambridge, Massachusetts 02139, USA and at the Department of Neuroophthalmology of the University Eye Clinic in D7400 Tubingen, West Germany. The interactions between illusory and real contours have been investigated under monocular, binocular and dichoptic conditions. Results show that under all three presentation conditions, periodic alternations, generally called rivalry, occur during the perception of cognitive (or illusory) triangles, while earlier research had failed to find such rivalry (Bradley and Dumais, 1975). With line triangles, rivalry is experienced only under dichoptic conditions. A model is proposed to account for the observed phenomena
Computation of texture and stereoscopic depth in humans by Manfred Fahle( Book )

3 editions published in 1989 in English and held by 4 WorldCat member libraries worldwide

The computation of texture and of stereoscopic depth is limited by the eyes and by the subsequent stage of visual system in humans, and by the quality of the optical 'front end' as well as by the computational hard- and software in machines. The quality of the optics and the resolution of the opto- electronic transducer (e.g. the retina) limit spatial resolution, and, consequently, the discrimination of textures. In stereoscopic depth, thresholds far below the grain of the input-device (in humans: the photoreceptor diameter) can be attained. This extreme accuracy in locating a stimulus, called hyperacuity, is due to interpolation between the positions of the input elements, such as the photoreceptors in humans. Interpolation is most likely a feat achieved by the visual cortex, depending on a good signal-to-noise ratio of the stimulus representation. Again, resolution and contrast modulation are critical factors
Limits of precision for human eye motor control by Manfred Fahle( Book )

3 editions published in 1989 in English and held by 4 WorldCat member libraries worldwide

If the two segments of a vernier targe are presented to different eyes, i.e., dichoptically, thresholds are three to four times higher than with presentation to the same eye. This increase in thresholds is mainly due to uncorrelated movements of both eyes, such as tremor and drifts, that occur even under steady fixation. The psychophysically measured thresholds allow one to calculate an upper estimate for the amplitudes of uncorrelated eye movements during fixation. This estimate matches the best results from direct eye position recording, with the calculated mean amplitude of eye tremor corresponding to roughly one photo-receptor-diameter. The combined amplitude of both correlated and uncorrelated eye movements was also measured by delaying one segment of the vernier relative to its partner under monocular or dichoptic conditions. Fixation proved to be relatively stable, and trained observers could sustain eye position within a few arcmin. Keywords: Hyperactivity. (KR)
Synthesis of visual modules from examples : learning hyperacuity by Tomaso Poggio( Book )

3 editions published in 1991 in English and held by 4 WorldCat member libraries worldwide

For any given visual competence, it is tempting to conjecture a specific algorithm and a corresponding neural circuitry. It has been often implicitly assumed that this machinery may be hardwired in the brain. This extreme point of view, if taken seriously, amy quickly lead to absurd consequences. The underlying reason for the spectacular performance of human subjects in these tasks is that the information sampled by the photoreceptors and relayed to the brain does contain the information necessary for precise localization of image features, since the spacing between photoreceptors and the eye's optics satisfy (in the fovea) the constraints of the sampling theorem. More specifically, it has been shown that, in principle, spatial mechanisms that account for grating resolution are sensitive enough to support hyperacuity-level performance. Furthermore, some of the hyperacuity tasks can be solved by detecting 'secondary' cues such as luminance difference (as in the bisection task) or orientation (as in the detection of vertical vernier stimuli). The detailed structure of the neural circuitry that subserves the detection of these cues, or hyperacuity performance in other tasks is, however, unknown
Parallel computation of vernier offsets, curvature, and chevrons in humans by Manfred Fahle( Book )

2 editions published in 1989 in English and held by 3 WorldCat member libraries worldwide

A vernier offset is detected at once among straight lines, and reaction times are almost independent of the number of simultaneously presented stimuli (distractors), even if absolute orientation cues are masked by varied orientation of the verniers. This result implies that the human visual system processes vernier offsets in parallel. Reaction times for identifying one straight target among offset verniers, on the other hand, increase with the number of stimuli. The same is true for the identification of a vernier offset to one side among verniers offset to the opposite side, if absolute orientation cues are masked. These tasks require serial or semi-parallel processing. Chevrons and curved targets show the same pattern of results. Even deviations below a photoreceptor diameter can be detected at once. The visual system thus attains positional accuracy below the photoreceptor diameter simultaneously at different positions. I conclude that deviation from straightness, or change of orientation, is detected in parallel over the visual field. Discontinuities or gradients in orientation may represent an elementary feature of Parallel processing, Human psychophysics, Hyperacuity, Early vision
Neuronale Korrelate zerebral bedingter visueller Wahrnehmungsstörungen by Maren Praß( )

1 edition published in 2013 in German and held by 3 WorldCat member libraries worldwide

Elektrophysiologische und bildgebende Untersuchungen zum Einfluss visueller Aufmerksamkeit auf die Objektwahrnehmung des Menschen by Daniela Gledhill( )

1 edition published in 2013 in German and held by 2 WorldCat member libraries worldwide

Fast perceptual learning in visual hyperacuity by Tomaso Poggio( Book )

2 editions published in 1991 in English and held by 2 WorldCat member libraries worldwide

In particular, we show that fast stimulus-specific learning indeed takes place in the human visual system and that this learning does not transfer between two slightly different hyperacuity tasks."
Mit Büchse, Schweisshund und Skizzenblock by Manfred Fahle( Book )

1 edition published in 2003 in German and held by 2 WorldCat member libraries worldwide

Wie kommen Bilder in das Gehirn? : die Sicht der Hirnforschung( )

1 edition published in 2007 in German and held by 2 WorldCat member libraries worldwide

Interference control in healthy and pathological ageing by Margarethe Korsch( )

1 edition published in 2015 in English and held by 2 WorldCat member libraries worldwide

Analysis and modeling of visual invariance for object recognition and spatial cognition by Sven Eberhardt( )

1 edition published in 2015 in English and held by 2 WorldCat member libraries worldwide

Disparity gradients and depth scaling by Heinrich H Bülthoff( Book )

3 editions published in 1989 in English and held by 1 WorldCat member library worldwide

The binocular perception of shape and of depth relations between objects can change considerably if the viewing direction is changed only by a small angle. We explored this effect psychophysically and found a strong depth reduction effect for large disparity gradients. The effect is found to be strongest for horizontally oriented stimuli, and stronger for line stimuli than for points. This depth scaling effect is discussed in a computational framework of stereo based on a Baysian approach which allows to integrate information from different types of matching primitives weighted according to their robustness. Keywords: Stero; Artificial intelligence; Computer vision; Depth scaling; Disparity gradients; Computational vision
On the shifter hypothesis for the elimination of motion blur by Manfred Fahle( Book )

2 editions published in 1990 in English and held by 1 WorldCat member library worldwide

Abstract: "Objects moving at even moderate speeds stimulate many retinal photoreceptors within the integration time of the receptors, yet usually, no motion blur is experienced. An elegant model for the elimination of motion blur was proposed by Anderson and van Essen (1987) who suggested that the neuronal representation of the retinal image is shifted on its way to the cortex, in an opposite direction to the motion. Thus, the cortical representation of objects would be stationary at least during short periods of time. I have measured thresholds for two vernier stimuli, moving simultaneously into opposite directions over identical parts of the retina. Motion blur for these stimuli is not stronger than with a single moving stimulus, and thresholds can be below a photoreceptor diameter
Wie es im Gehirn zugeht Agnosien und andere Sehstörungen [video lecture]( )

1 edition published in 2006 in German and held by 1 WorldCat member library worldwide

Specific aspects in the adaptation of human Eye-Hand-Coordination by Mona Bornschlegl( )

1 edition published in 2011 in English and held by 1 WorldCat member library worldwide

Prism adaptation, motor control, spatial mapping, spatial alignment, rhythmic sound, generalisation, virtual reality, learning to learn, dual-adaptation. - Sensorimotor control, especially eye-hand-coordination, enables us to interact with our environment. In my dissertation I describe and discuss three specific aspects of the adaptation of eye-hand-coordination: 1) the relative weight of visual and proprioceptive adaptation, 2) spatial and proprioceptive generalization of adaptation, and 3) acquisition of alternative mappings with repeated adaptations. The first aspect of sensorimotor adaptation is how an ambiguous mismatch between visual and proprioceptive coordinate systems is resolved. In my experiment I showed that an auditory pacing signal is an important factor facilitating visual adaptation. As a second aspect I examined the generalization of prism adaptation over space. Based on my results I can explain all previous results as an underestimation of change in the guiding system. The third aspect is the acquisition of alternate mappings (dual-adaptation) together with learning to learn. Confirming the involvement of learning to learn, I also found that the efficiency of dual-adaptation only depends on the total number of trials irrespective of their segmentation in blocks of differing lengths
 
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Perceptual learning
Languages
English (47)

German (12)

Covers
The neuropsychology of vision