Filters: Collection: "ir_uspace" Type: "Text"
| Creator | Title | Description | Subject | Date | ||
|---|---|---|---|---|---|---|
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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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Normann, Richard A. | Visual Neuroprosthetics: Functional Vision for the Blind | Resent progress in materials and microfabrication technologies have allowed researchers to reconsider the prospect of providing a useful visual sense to the profoundly blind. This will be accomplished by electrically stimulating their visual systems via an array of implanted microelectrodes. T... | Visual Neuroprosthetics; Vision; Blindness | 1995-01 |
| 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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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 |
| 5 |
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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 |
| 6 |
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Angelucci, Alessandra | Multiple components of surround modulation in primary visual cortex: Multiple neural circuits with multiple functions? | The responses of neurons in primary visual cortex (V1) to stimulation of their receptive field (RF) are modulated by stimuli in the RF surround. This modulation is suppressive when the stimuli in the RF and surround are of similar orientation, but less suppressive or facilitatory when they are cross... | 2014-01-01 | |
| 7 |
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Angelucci, Alessandra | Segregation and overlap of callosal and association neurons in frontal and parietal cortices of primates: a spectral and coherency analysis. | The spatial relations between selected classes of association and callosal neurons were studied in the frontal and parietal lobes of the macaque monkey using retrogradely transported fluorescent dyes. Fast blue and nuclear yellow were injected in the left frontal (areas 4 and 6) and right posterior ... | Macaca fascicularis; Parietal Lobe; Neurons | 1989 |
| 8 |
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Normann, Richard A.; Maynard, Edwin M. | Neuronal interactions improve cortical population coding of movement direction | Interactions among groups of neurons in primary motor cortex (MI) may convey information about motor behavior. We investigated the information carried by interactions in MI of macaque monkeys using a novel multielectrode array to record simultaneously from 12-16 neurons during an arm-reaching task. ... | Motor Cortex; Monkey; Population Coding; Movement | 1999 |
| 9 |
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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 |
| 10 |
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Gerig, Guido | Functional connectivity MR imaging reveals cortical functional connectivity in the developing brain | BACKGROUND AND PURPOSE: Unlike conventional functional MR imaging where external sensory/cognitive paradigms are needed to specifically activate different regions of the brain, resting functional connectivity MR imaging acquires images in the absence of cognitive demands (a resting condition) and de... | 2008-01-01 | |
| 11 |
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Angelucci, Alessandra | Layer-specific programs of development in neocortical projection neurons | How are long-range axonal projections from the cerebral cortex orchestrated during development? By using both passively and actively transported axonal tracers in fetal and postnatal ferrets, we have analyzed the development of projections from the cortex to a number of thalamic nuclei. We report th... | Axonal Transport; Efferent Pathways; Brain Mapping | 1995 |
| 12 |
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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 | |
| 13 |
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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 |
| 14 |
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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 |
| 15 |
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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 | |
| 16 |
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Creem-Regehr, Sarah Hope; Gooch, Amy A.; Sahm, Cynthia S.; Thompson, William B. | Perceiving virtual geographic slant: action influences perception | Four experiments varied the extent and nature of observer movement in a virtual environment to examine the influence of action on estimates of geographical slant. Previous slant studies demonstrated that people consciously overestimate hill slant but can still accurately guide an action toward th... | Geographical slant; Virtual environment | 2003-06-16 |
| 17 |
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Olson, Randall J.; Coldwell, Karin D.; Compton, Bruce J.; Giddings, John C. | Sedimentation field-flow fractionation: a method for studying particulates in cataractous lens | It is shown that the technique of sedimentation field-flow fractionation (sedimentation [sed] FFF) can be used to determine the particle content and particle size distribution of normal and cataractous lenses. A 31-year-old normal human lens, for example, showed a particle content of 1.5% by weight ... | Fractionation; Cataractous Lens; Particulates | 1984 |
| 18 |
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Olson, Randall J. | Clinical experience with 21-gauge manual microphacoemulsification using Sovereign WhiteStar Technology in eyes with dense cataract | PURPOSE: To present a series of patients who had 21-gauge microphacoemulsification using Sovereign WhiteStar technology. SETTING: John A. Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, USA. METHODS: Eighteen consecutive patients with cataracts judged to be 3+ or 4+ on... | Cataract; Microsurgery; Phacoemulsification; Postoperative Complications; Visual Acuity | 2004-01 |
| 19 |
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Normann, Richard A.; Shah, Maulik R. | Study of printed spiral coils for neuroprosthetic transcranial telemetry applications | We have explored the use of printed spiral coils (PSC's) for neuroprosthetic transcranial telemetry applications. We fabricated two-dimensional PSC's on a thin (25 microns) polyimide substrate using copper (35 microns) as a conducting material. All the coils had a fixed inner diameter of 1.0 cm. We ... | Blindness; Neuroprosthesis; Transcranial Telemetry System; Prosthesis Design | 1998 |
| 20 |
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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 |
| 21 |
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Angelucci, Alessandra | Experimentally induced retinal projections to the ferret auditory thalamus: development of clustered eye-specific patterns in a novel target | We have examined the relative role of afferents and targets in pattern formation using a novel preparation, in which retinal projections in ferrets are induced to innervate the medial geniculate nucleus (MGN). We find that retinal projections to the MGN are arranged in scattered clusters. Clusters a... | Retina; Ferrets | 1997 |
| 22 |
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Angelucci, Alessandra | Role for nitric oxide in the development of the ferret retinogeniculate projection | The ferret retinogeniculate projection segregates into eye-specific layers during the first postnatal week and into ON/OFF sublaminae, which receive inputs from either on-center or off-center retinal ganglion cells, during the third and fourth postnatal weeks. The restriction of retinogeniculate axo... | Enzyme Inhibitors; Visual Pathways; Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate | 1996 |
| 23 |
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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 | |
| 24 |
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Digre, Kathleen B.; Skuster, Denise Z. | Neurologic conditions presenting as psychiatric disorders. | Understanding underlying neuroanatomic function helps physicians to localize defects and search for treatable neurologic conditions. Neurologic conditions such as Huntington's chorea, Wilson's disease, Gille de la Tourette syndrome, brain tumors, encephalitis and meningitis, neurodegenerative condit... | Psychiatric Diagnosis; Neurologic Disease | 1992-06-15 |
| 25 |
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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 |