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Creator | Title | Description | Subject | Date |
1 |
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Horch, Kenneth W.; Normann, Richard A. | Noble metal penetrating cortical stimulating electrode array: preliminary results | Electrical stimulation of the visual cortex causes subjects to see spots of light (phosphenes) in their visual fields. We have developed arrays of penetrating electrodes which may from the basis of a visual prosthesis centered around electrical stimulation of the visual cortex. These arrays have bee... | Visual prosthesis | 1988 |
2 |
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Horch, Kenneth W.; Normann, Richard A. | Simulation of a phosphene field based visual prosthesis | A visual prosthesis for the blind based upon electrical stimulation of the visual cortex requires the development of an array of electrodes. To establish design specifications for such an electrode array, we have conducted psychophysical experiments with normally sighted subjects wearing a portable... | Visual prosthesis; Phosphene simulator | 1990 |
3 |
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Normann, Richard A.; Maynard, Edwin M. | Neural interface for a cortical vision prosthesis | The development of a cortically based vision prosthesis has been hampered by a lack of basic experiments on phosphene psychophysics. This basic research has been hampered by the lack of a means to safely stimulate large numbers of cortical neurons. Recently, a number of laboratories have developed a... | Neuroprosthetics; Artificial Vision; Electrode Arrays; Multielectrode Recordings; Biocompatibility | 1999 |
4 |
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Angelucci, Alessandra; Lund, Jennifer S. | Circuits for local and global signal integration in primary visual cortex | Contrast-dependent changes in spatial summation and contextual modulation of primary visual cortex (V1) neuron responses to stimulation of their receptive field reveal long-distance integration of visual signals within V1, well beyond the classical receptive field (cRF) of single neurons. To identif... | Primary Visual Cortex; Extrastriate Cortex; Feed-back Connections; Lateral Connections; SUrround Modulation; Macaque | 2002-10-01 |
5 |
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Normann, Richard A.; Horch, Kenneth W.; Cha, Kichul | Mobility performance with a pixelized vision system | A visual prosthesis, based on electrical stimulation of the visual cortex, has been suggested as a means for partially restoring functional vision in the blind. The prosthesis would create a pixelized visual sense consisting of punctate spots of light (phosphenes). The present study investigated the... | Visual Prosthesis; Mobility; Phosphene Simulator | 1992 |
6 |
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Normann, Richard A. | Functional reorganization of primary visual cortex induced by electrical stimulation in the cat. | Compared to the high degree of plasticity observed in a juvenile, mature sensory cortices have long been held to be immutable but, recently, researchers have suggested some plasticity persists in the mature cortex. Cortical reorganization has particular saliency to the development of a cortically ba... | Cat; Electrophysiology; Phosphene; Plasticity; Receptive Field; Striate Cortex | 2005 |
7 |
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Mathews, V. John | A new model of perceptual threshold functions for application in image compression systems | This paper discusses the development of a perceptual threshold model for the human visual system. The perceptual threshold functions describe the levels of distortions present at each location in an image that human observers can not detect. Models of perceptual threshold functions are useful in ima... | | 1995 |
8 |
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Normann, Richard A.; Campbell, Patrick K.; Jones, Kelly E.; Huber, Robert J.; Horch, Kenneth W. | Silicon-based, three-dimensional neural interface: manufacturing processes for an intracortical electrode array | A method has been developed for the manufacture of a "three-dimensional" electrode array geometry for chronic intracortical stimulation. This silicon based array consists of a 4.2 x 4.2 x 0.12 mm thick monocrystalline substrate, from which project 100 conductive, silicon needles sharpened to facilit... | Electric Stimulation; Electrodes, Implanted; Sensory Cortex; Intracortical Electrode Array | 1991 |
9 |
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Baxter, Brent S. | Image processing in the human visual system | This work extends the multiplicative visual model to include image texture as suggested by experiments [Campbell, Weisel] linking a low resolution Fourier analysis with neurons in certain parts of the visual cortex. The new model takes image texture into account in the sense that weak texture is acc... | Human visual system; Image texture | 1975 |
10 |
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Mathews, V. John | Neural decoding using a nonlinear generative model for brain-computer interface | Kalman filters have been used to decode neural signals and estimate hand kinematics in many studies. However, most prior work assumes a linear system model, an assumption that is almost certainly violated by neural systems. In this paper, we show that adding nonlinearities to the decoding algorithm ... | | 2014-01-01 |
11 |
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Mathews, V. John | Subband vector quantization of images using hexagonal filter banks | Abstract Results of psychophysical experiments on human vision conducted in the last three decades indicate that the eye performs a multichannel decomposition of the incident images. This paper presents a subband vector quantization algorithm that employs hexagonal filter banks. The hexagonal filte... | | 1992 |
12 |
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Tasdizen, Tolga; Jones, Bryan W.; Whitaker, Ross T.; Marc, Robert E. | Ultrastructural mapping of neural circuitry: a computational framework | Complete mapping of neuronal networks requires data acquisition at synaptic resolution with canonical coverage of tissues and robust neuronal classification. Transmission electron microscopy (TEM) remains the optimal tool for network mapping. However, capturing high resolution, large, serial sectio... | | 2009 |
13 |
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Shirley, Peter S. | Natural image statistics for computer graphics | The class of all natural images is an infinitely small fraction of all possible images. The structure of natural images can be statistically modeled, revealing striking regularities. The human visual system appears to be optimized to view natural images, as opposed to any possible image, and therefo... | Natural image | 2001 |
14 |
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Harrison, Reid R. | Wireless integrated circuit for 100-channel neural stimulation | We present the design of an integrated circuit for wireless neural stimulation, along with bench-top and in-vivo experimental results. The chip has the ability to drive 100 individual stimulation electrodes with constant-current pulses of varying amplitude, duration, interphasic delay, and repetiti... | Wireless; Integrated Neural Interface; Neural recording; Telemetry | 2008-11 |
15 |
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Tasdizen, Tolga; Foster, Norman L. | Automatic classification of alzheimer's desease vs. frontotemporal dementia: a spatial decision tree aprroach with FDG-PET | We introduce a novel approach for the automatic classification of FDG-PET scans of subjects with Alzheimers Disease (AD) and Frontotemporal dementia (FTD). Unlike previous work in the literature which focuses on principal component analysis and predefined regions of interest, we propose the combined... | | 2008 |
16 |
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Faugeras, Olivier Dominique | Digital color image processing and psychophysics within the framework of a human visual model | A three-dimensional homomorphic model of human color vision based on neurophysiological and psychophysical evidence is presented. This model permits the quantitative definition of perceptually important parameters such as brightness. saturation, huo and strength. By modelling neural interaction in t... | Human visual model; Neurophysiological evidence; Psychophysical evidence | 1977 |
17 |
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Mathews, V. John | An optimal design procedure for intraband vector quantized subband coding | AbstTact- Subband coding with vector quantization is addressed in this paper. Forming the data vectors from both between and within the subbands is considered. The former of these two schemes is referred to as interband coding and the latter as intraband coding. Interband coder design is relatively ... | | 1995 |
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Normann, Richard A.; Campbell, Patrick K.; Jones, Kelly E. | 100 electrode intracortical array: structural variability | A technique has been developed for fabricating three dimensional "hair brush" electrode arrays from monocrystalline silicon blocks. Arrays consist of a square pattern of 100 penetrating electrodes, with 400 microns interelectrode spacing. Each electrode is 1.5mm in length and tapers from about 100 m... | Microelectrode arrays; Stimulation; Micromachining | 1990 |
19 |
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Harrison, Reid R. | HermesC: low-power wireless neural recording system for freely moving primates | Neural prosthetic systems have the potential to restore lost functionality to amputees or patients suffering from neurological injury or disease. Current systems have primarily been designed for immobile patients, such as tetraplegics functioning in a rather static, carefully tailored environment.... | Brain-machine interface; Low power; Neural prosthetics; Telemetry; Wireless; Neural recording; HermesC | 2009-08 |
20 |
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Harrison, Reid R. | Versatile integrated circuit for the acquisition of biopotentials | Electrically active cells in the body produce a wide variety of voltage signals that are useful for medical diagnosis and scientific investigation. These biopotentials span a wide range of amplitudes and frequencies. We have developed a versatile front-end integrated circuit that can be used to amp... | Biopotential; Neural recording; Electrodes; Amplifier | 2007-09 |
21 |
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Normann, Richard A.; Shoham, Shy | Encoding mechanisms for sensory neurons studied with a multielectrode array in the cat dorsal root ganglion | Recent advances in microelectrode array technology now permit a direct examination of the way populations of sensory neurons encode information about a limb's position in space. To address this issue, we recorded nerve impulses from about 100 single units simultaneously in the L6 and L7 dorsal root ... | Sensory; Encoding; Multielectrode; Dorsal Root Ganglion; Cutaneour; Muscle | 2004 |
22 |
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Tasdizen, Tolga; Jones, Bryan W.; Whitaker, Ross T. | Computational framework for ultrastructural mapping of neural circuitry | Circuitry mapping of metazoan neural systems is difficult because canonical neural regions (regions containing one or more copies of all components) are large, regional borders are uncertain, neuronal diversity is high, and potential network topologies so numerous that only anatomical ground truth c... | | 2009 |
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Horch, Kenneth W.; Dhillon, Gurpreet S. | Direct neural sensory feedback and control of a prosthetic arm | Evidence indicates that user acceptance of modern artificial limbs by amputees would be significantly enhanced by a system that provides appropriate, graded, distally referred sensations of touch and joint movement, and that the functionality of limb prostheses would be improved by a more natural co... | Peripheral Nerve Implant; Prosthetic Limb Control; Sensory Feedback | 2005-12 |
24 |
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Horch, Kenneth W. | Differential activation of nerve fibers with magnetic stimulation in humans | Earlier observations in our lab had indicated that large, time-varying magnetic fields could elicit action potentials that travel in only one direction in at least some of the myelinated axons in peripheral nerves. The objective of this study was to collect quantitative evidence for magnetically in... | Magnetic stimulation; Peripheral nerve; Electromyographic potential; Somatosensory potential | 2006 |
25 |
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Freire, Juliana; Silva, Claudio T. | VisMashup: streamlining the creation of custom visualization applications | Visualization is essential for understanding the increasing volumes of digital data. However, the process required to create insightful visualizations is involved and time consuming. Although several visualization tools are available, including tools with sophisticated visual interfaces, they are o... | VisMashup; Dataflow; Visualization systems; Mashups; Medleys | 2009-11 |