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| | Visual cortex - Wikipedia, the free encyclopedia |
 | | Visual area V4 is not tuned for complex objects such as faces, as areas in the inferotemporal cortex are. | | | It is the part of the cerebral cortex that is responsible for processing visual stimuli. | | | The functionally defined primary visual cortex is approximately equivalent to the anatomically defined striate cortex. |
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http://en.wikipedia.org/wiki/Visual_cortex
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| | Visual Development |
| | Visual experience is crucial for a child's vision to develop normally -- a "use it or lose it" situation. | | | The key research on visual development began during the 1950s and 1960s, when scientists began to explore the visual cortex in cats and monkeys. | | | Scientists studying the visual cortex discovered columns of neurons that selectively respond to visual information from one eye or the other. |
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http://web.sfn.org/content/Publications/BrainBriefings/visual_development.html
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| | visual cortex |
| | The LGN is the main conduit to the visual cortex and conscious visual perception. | | | The visual cortex contains a columnar organization, meaning that neurons within a column perpendicular to the surface of the cortex have similar response properties - i.e., similar position, orientation, and spatial-frequency selectivities. | | | Simple-cells are quite choosy about the position of the edge, whereas complex-cells will respond to the edge as long as it is in some general region of the image. |
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http://redwood.ucdavis.edu/bruno/psc129/lecture-notes/visual-cortex.html
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| | Research - Stimulation of Visual Cortex |
| | Restoration of vision, using a neuroprosthesis, depends upon providing the cortex with a well-controlled temporospatial electrical stimulation pattern that mimics the pattern of neural activity normally associated with vision, or uses the natural tuning properties of the visual system, to provide the cortex with meaningful sensory input. | | | That this approach could work is suggested by the retinotopy of striate cortex and by a number of human and animal experiments demonstrating the feasibility of chronic electrode implants. | | | Attempts to stimulate vision by electrically stimulating the cerebral cortex go back at least to 1918, when Lowenstein and Borchardt accidentally stimulated the striate (visual) cortex of a man undergoing surgery for a bullet wound to the head. |
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http://www.iit.edu/~npr/visualprosthesis2.htm
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| | The Primary Visual Cortex |
| | Such experiments show that the visual cortex learns from experience, and self-organizes its structure to process visual input. | | | Because it very similar to the rest of the neocortex in its anatomical structure, it is widely believed that understanding the structure and function of the primary visual cortex will provide fundamental insights into how the neocortex operates. | | | Remarkably however, the patterns of orientation and ocular dominance are not fixed genetically, but develop from visual experience, mostly after birth. |
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http://nn.cs.utexas.edu/web-pubs/sirosh/pvc.html
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| | [No title] |
| | From basic stimulation of the cortex, prostheses are now able to approximate the visual sense to the extent that patients have the ability to see adaptively. | | | The fact that visual ability can be restored despite photoreceptor loss illustrates an important fact of mammalian eyesight: vision does not occur in the eyes but only after undergoing substantial modification by various structures of the brain. | | | For example, visual information synapses with regions of the thalamus, specifically the superior colliculus, on its way to the visual cortex. |
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http://www.ohsu.edu/psychiatry/fbi/mattsthesis/thesis.doc
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| | Synchronous Neural Activity in the Visual Cortex |
| | The notion that excitable neurons can synchronize their firing activity rapidly is important for understanding its role in visual processing, especially in such tasks as visual tracking. | | | Therefore, we have proposed that achieving firing synchrony between neurons processing the same object might be a mechanism to increase the contrast between the object and its background. | | | Our results showed that the occurrence of firing synchrony can be triggered by changes in the excitability of the neurons in the visual cortex. |
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http://www.ks.uiuc.edu/Research/Neural/synchronous.html
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| | Central Visual Pathways |
| | Temporal visual areas (such as V4 and IT) are involved with the complex perception of patterns and forms as recognizable objects. | | | This highway of visual information courses through the white matter of the temporal and parietal lobes, and can be very vulnerable to strokes. | | | These two types of information, motion vs. color and form, are maintained in separate compartments all the way up the visual pathway. |
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http://thalamus.wustl.edu/course/cenvis.html
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| | Visual Intelligence |
| | But we are largely ignorant that there is even such a thing as visual intelligence---that is, until it is severely impaired, as in the case of Mr. | | | Your images must pass the scrutiny of a customer's visual intelligence before they can go on to convince her rational intelligence of a need and her emotional intelligence of a desire for your product. | | | Our visual intelligence richly interacts with, and in many cases precedes and drives, our rational and emotional intelligence. |
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http://www.cogsci.uci.edu/personnel/hoffman/vi.html
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| | Lower brain activity in visual cortex associated with dyslexia (11/97) |
| | But it is difficult to imagine that such an abnormality in a significant visual pathway would not have some effect on a visually complex behavior like reading, the researchers have concluded. | | | The researchers also found a weaker but still positive correlation between activity in the primary visual cortex and reading speed, which provides additional support for the hypothesis that the underlying problem lies in the visual system at or before the visual cortex. | | | Physiological differences should exist between dyslexics and non-dyslexics at the primary visual cortex or earlier in the visual pathway. |
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http://www.stanford.edu/dept/news/pr/97/971125dyslexia.html
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| | UTCS Neural Nets Group Research: Visual Cortex |
| | These demonstrate how perception may be occurring in the adult cortex, with a level of detail not possible to achieve with current biological and psychophysical measurement methods. | | | Our goal is to understand how orientation tuning and direction selectivity simultaneously develop in the visual cortex. | | | In conjunction with research on the tilt aftereffect (above), a number of visualizations of orientation perception have been developed. |
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http://nn.cs.utexas.edu/pages/research/visualcortex.html
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| | visual cortex |
| | The part of the brain that detects the forms of objects, brightness of the individual parts of the objects, shading, and spatial organization of the visual scene. |
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http://daviddarling.info/encyclopedia/V/visual_cortex.html
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| | Development of Orientation Preference Maps in Ferret Primary Visual Cortex -- Chapman et al. 16 (20): 6443 -- Journal ... |
| | The patterning of iso-orientation domains in ferret primary visual cortex thus is established early in development and remains stable over time, unaffected by either normal visual experience or the anatomical rearrangements of geniculocortical afferents into eye-specific domains. | | | The development of orientation preference maps was studied in ferret primary visual cortex using chronic optical imaging of intrinsic signals. | | | The Role of Visual Experience in the Development of Columns in Cat Visual Cortex |
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http://www.jneurosci.org/cgi/content/abstract/16/20/6443
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| | Disruption of orientation tuning visual cortex by artificially correlated neuronal activity |
| | Effect of neonatal unilateral enucleation on the development of orientation selectivity in the primary visual cortex of normally and dark-reared kittens. | | | Disruption of orientation tuning visual cortex by artificially correlated neuronal activity | | | This is consistent with activity having an instructive role in shaping cortical neuron receptive field tuning properties. |
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http://www.nature.com/doifinder/10.1038/386680a0
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| | Associate Professor Marcello Rosa |
| | One of the primary objectives of this research is to identify the functions of neurones in the different areas of the cerebral cortex. The laboratory personnel includes Dr James Bourne, an ARC Research Fellow, Dr Kathleen Burman, an NHMRC-funded postdoctoral researcher, Ms Hazel Barber, histology technician, and two PhD students (Leo Lui and Susan Palmer). | | | Associate Professor Rosa's laboratory is investigating the organisation of the visual pathways in mammals, with special emphasis on the cerebral cortex. There are many visual areas in the brain, but it is still unclear how neurones in these areas interact in order to create an internal representation of the "outside world". | | | Rosa MGP (2002) Visual maps in the adult primate cerebral cortex. Brazilian Journal of Medical and Biological Research, 35, 1485-1498. |
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http://www.med.monash.edu.au/physiology/staff/rosa.html
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| | Neuroscience for Kids - Braille and the Brain |
| | For example, the occipital cortex is thought to be used mainly for visual processing. | | | The early-blind subjects had even more activity in the visual cortex than the late-blind subjects. | | | The late-blind subjects, though, already had many visual connections. |
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http://faculty.washington.edu/chudler/brail.html
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| | Neuroscience for Kids - Visual Pathway |
| | The pathways stay this way and all the way up to the visual cortex. | | | The Visual Pathway: From Eye to Primary Visual Cortex | | | Like many pathways in the nervous system, right and left visual information cross to the other side of the brain. |
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http://faculty.washington.edu/chudler/vispath.html
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| | A NEW LOOK AT SEEING: A Model of the Primary Visual Cortex |
| | Their impact on the retina triggers impulses that travel a pathway along the optic nerve through the thalamus to the back of the brain, where they register on the primary visual cortex. | | | These and other experiments suggest that the interconnections between neurons aren't fixed at birth, but evolve depending on visual experience. | | | A NEW LOOK AT SEEING: A Model of the Primary Visual Cortex |
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http://www.psc.edu/MetaCenter/MetaScience/Articles/Miikkulainen/Miikkul.html
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| | Brain's Visual Cortex Doesn't "Tell" All It Knows |
| | "Your visual cortex isn’t telling you everything." The work was supported by the National Institutes of Health and the Alfred P. Sloan Foundation. | | | First View Of Many Neurons Processing Information In Living Brain (January 28, 2005) -- Harvard Medical School researchers have applied a new microscopy technique in a living animal brain that for the first time reveals highly sophisticated time-lapse images of many neurons coordinating... | | | "This suggests that not everything in the cortex can become conscious knowledge," said He. |
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http://www.sciencedaily.com/releases/2001/05/010529070018.htm
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| | The Development of the Primary Visual Cortex |
| | The study of models of the primary visual cortex and the LGN have been major topics in our group. | | | At this stage in the processing some analysis begins to take place. | | | Included in the model are the functions of the retina, the lateral geniculate nucleus (LGN), and the primary visual cortex. |
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http://www.ks.uiuc.edu/Research/Neural/development.html
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| | Primary Visual Cortex II |
| | Synchronization of oscillatory responses in visual cortex correlates with perception in interocular rivalry. | | | The primary visual cortex is perhaps the best understood area of the whole cerebral cortex. | | | Cottaris, N.P. and DeValois, R.L. Temporal dynamics of chromatic tuning in macaque primary visual cortex. |
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http://www.ini.unizh.ch/~peterk/Lectures/V1course.II.html
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| | Modeling of orientation selectivity in the visual cortex |
| | According to the concept of columnar organization, the neighboring neurons in the visual cortex have similar orientation tunings and comprise an orientation column or iso-orientation domain (Hubel and Wiesel, 1974). | | | Our explanation for this phenomenon is that neurons with more response latency start firing later, on the background of orientation-dependent inhibition provided by neurons with shorter response latencies (which, in turn, do not show orientation sensitivity in the initial phase of responses). | | | the initial phases of neuron responses encode the location of visual stimuli (edges) whereas the later phases encode the stimulus orientations. |
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http://www.rybak-et-al.net/iod.html
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| | Modeling of Neuronal Activity in the Visual Cortex |
| | In the primate visual pathway, orientation tuning of neurons is first observed in the primary visual cortex. | | | Modeling of Neuronal Activity in the Visual Cortex | | | The result is a set of nonlinear spatio-temporal integral equations for ``phase-averaged'' firing rates across the model cortex. |
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http://www.math.nyu.edu/faculty/shelley/neuronal/neuronal_activity.html
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| | Sereno: Human visual cortical areas |
| | An increased emphasis on the center of gaze in human V1 is evident. | | | In the course of this work, we developed a method for reconstructing the complete cortical surface of individual subjects from MRI images. | | | Visual areas in humans show a close resemblance to visual areas originally defined in monkeys. |
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http://cogsci.ucsd.edu/~sereno/brain.html
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| | Dorlands Medical Dictionary |
| | (kor”tĭ-ko-spi´nəl) pertaining to or connecting the cortex of the brain and the spinal cord. | | | (kor”tĭ-kəl-os”te-ot´ə-me) osteotomy through the bone cortex at the base of the dentoalveolar segment, which serves to weaken the resistance of the bone to the application of orthodontic forces. | | | the area of the occipital lobe of the cerebral cortex concerned with vision; it consists of the first visual area or striate c. |
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http://www.mercksource.com/pp/us/cns/cns_hl_dorlands.jspzQzpgzEzzSzppdocszSzuszSzcommonzSzdorlandszSzdorlandzSzdmd_c_57zPzhtm
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| | Organization And Function Of The Visual Cortex In Primates |
| | We use these approaches (i) to analyze left-right asymmetries in the cerebral cortex of normal human subjects; (ii) to reveal localized shape differences associated with specific neurological disorders; and (iii) to objectively evaluate a variety of proposed homologies between monkey and human cortical areas. | | | Our laboratory uses physiological, anatomical and computational approaches to study the cerebral cortex. | | | One major focus is on information processing in the primate visual cortex in monkeys and humans. |
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http://research.medicine.wustl.edu/ocfr/research.nsf/s/9DE985996B1EBFAE8625677D005941DD
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| | Reid Lab Movies Cat and Rat Visual Cortex |
| | m region of rat visual cortex during visual stimulation by drifting bars (indicated in upper right). | | | Neurons become brighter as they are activated by the visual stimulus. | | | Reid Lab Movies Cat and Rat Visual Cortex |
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http://neuro.med.harvard.edu/site/reidweb/movies.html
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