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  • pathways
  • Behavioral, anatomical, and neuroimaging measurements have demonstrated several changes in healthy aging visual pathways that may contribute to reduced visual acuity in aging. (scirp.org)
  • To narrow down our candidate list of correlated genes, we have selected only those genes that were previously found to be regulated by visual experience and associated with pathways implicated in OD plasticity. (frontiersin.org)
  • Mapping
  • used fMRI with traveling wave visual field mapping methods to show that V1 in healthy aging subjects has lower blood-oxygen-level-dependent (BOLD) activity compared to healthy young adults, but found no change in the overall size of V1. (scirp.org)
  • Importantly, their results also demonstrated that aging has no effect on fixation stability, thus paving the way for future aging studies also using visual field mapping methods, which rely on stable eye position for optimal measurements. (scirp.org)
  • 1996) Mapping striate and extrastriate visual areas in human cerebral cortex. (scirp.org)
  • neuronal
  • CSD is a wave of neuronal and glial depolarization, followed by long-lasting suppression of neural activity, which is easily evoked in mammals with lissencephalic ( 2 , 3 ) or folded cortex ( 4 ). (pnas.org)
  • Fluorescent latex microspheres as a retrograde neuronal marker for in vivo and in vitro studies of visual cortex. (wikipedia.org)
  • Disruption of orientation tuning in visual cortex by artificially correlated neuronal activity. (wikipedia.org)
  • Thus the claim is that when all these neuronal clusters oscillate together during these transient periods of synchronized firing, they help bring up memories and associations from the visual percept to other notions. (wikipedia.org)
  • Brodmann
  • Brodmann published his maps of cortical areas in humans, monkeys, and other species in 1909, along with many other findings and observations regarding the general cell types and laminar organization of the mammalian cortex. (wikipedia.org)
  • Brodmann areas have been discussed, debated, refined, and renamed exhaustively for nearly a century and remain the most widely known and frequently cited cytoarchitectural organization of the human cortex. (wikipedia.org)
  • One of the most widely used schemes came from Korbinian Brodmann, who split the cortex into 52 different areas and assigned each a number (many of these Brodmann areas have since been subdivided). (wikipedia.org)
  • sensory
  • In this chapter, discussion will be restricted (or broadened, depending upon one's viewpoint) to consideration of cortical zones shown to have at least some visual sensory responsiveness and direct connectivity with other, unimodal visual areas. (springer.com)
  • One important question is whether top-down expectation biases stimulus representations in early sensory cortex, i.e., whether the integration of prior knowledge and bottom-up inputs is already observable at the earliest levels of sensory processing. (jneurosci.org)
  • Here, we implicitly manipulated human subjects' prior expectations about visual motion stimuli, and probed the effects on both perception and sensory representations in visual cortex. (jneurosci.org)
  • Our results show that top-down expectations bias representations in visual cortex, demonstrating that the integration of prior information and sensory input is reflected at the earliest stages of sensory processing. (jneurosci.org)
  • Specifically, the question we wish to address is whether top-down expectations can bias stimulus representations in early sensory cortex. (jneurosci.org)
  • stimulus
  • In the visual cortex, neurons with selectivities for similar stimulus features often aggregate in specific layers, processing modules, and areas ( Nassi and Callaway, 2009 ). (jneurosci.org)
  • In the visual cortex, for example, stimulation of a pyramidal cell's receptive-field surround can attenuate the cell's response to a stimulus in the centre of its receptive field, a phenomenon called surround suppression. (biomedsearch.com)
  • 1979 ascertained the neuroplasticity of kittens' brains, with respect to control of visual stimulus correlated with changes in RNA structures. (wikipedia.org)
  • Traditionally, visual receptive fields were portrayed in two dimensions (e.g., as circles, squares, or rectangles), but these are simply slices, cut along the screen on which the researcher presented the stimulus, of the volume of space to which a particular cell will respond. (wikipedia.org)
  • The spatial-frequency theory of vision is based on two physical principles: Any visual stimulus can be represented by plotting the intensity of the light along lines running through it. (wikipedia.org)
  • brain
  • Our understanding of the visual system has reached new heights over the last decade, with new techniques based on brain metabolism, enzyme histochemistry, immunohistochemistry, voltage-sensitive dyes, and brain imaging having been applied rigorously to the study of the visual cortex (e.g. (springer.com)
  • Bender, D. B., 1983, Visual activation of neurons in the primate pulvinar depends on cortex but not colliculus, Brain Res . (springer.com)
  • It is generally accepted that in mammals visual information is sent to the brain along functionally specialized parallel pathways, but whether the mouse visual system uses similar processing strategies is not known. (jneurosci.org)
  • It is important to resolve this issue because the mouse brain provides a tractable system for developing a cellular and molecular understanding of disorders affecting spatiotemporal visual processing. (jneurosci.org)
  • 1992) Light regulates expression of brain-derived neurotrophic factor mRNA in rat visual cortex. (springer.com)
  • Cellerino A, Maffei L, Domenici L (1996) The distribution of brain-derived neurotrophic factor and its receptor trkB in parvalbumin-containing neurons of the rat visual cortex. (springer.com)
  • An international collaboration of neuroscientists have today published a paper in Nature demonstrating the breadth of neural communication in visual cortex using a combination of methods for tracing the projections of individual neurons across the brain. (ucl.ac.uk)
  • Firstly, they used whole-brain fluorescence-based axonal tracing by labelling neurons in the right visual cortex of each mouse with GFP and then imaging axonal projections by whole-brain serial two-photon tomography. (ucl.ac.uk)
  • The visual cortex has a critical job in processing and it's the most complex part of brain. (wikipedia.org)
  • so we decided to research on Human Vision System, besides we worked on Artificial Retinal image processing and new visionary optimization unit(Presented at Istanbul Technical University Conference(Turkey 2015-2016)) and grew our research to Visionary CORTEX of Brain" ,Michael Bidollahkhany said. (wikipedia.org)
  • Visual Centers in the Brain. (wikipedia.org)
  • When experimental participants read words that are presented to the left or right of their visual fixation (stimulating the opposite hemisphere of the brain first), the larger P2 for words in highly constraining contexts is observed only for right visual field presentation (targeting left hemisphere). (wikipedia.org)
  • According to Kanwisher & associates, the localized part of the brain responsible for this is the extrastriate cortex. (wikipedia.org)
  • The differences show up in a number of ways: the effects of localized brain damage, regional activity patterns exposed when the brain is examined using functional imaging techniques, connectivity with subcortical areas, and regional differences in the cellular architecture of the cortex. (wikipedia.org)
  • In a number of cases, brain areas are organized into topographic maps, where adjoining bits of the cortex correspond to adjoining parts of the body, or of some more abstract entity. (wikipedia.org)
  • The brain and the neural network should be considered as an integrated and self-contained firmware system that includes hardware (organs), software (programs), memory (short term and long term), database (centralized and distributed), and a complex network of active elements (such as neurons, synapses, and tissues) and passive elements (such as parts of visual and auditory system) that carry information within and in-and-out of the body. (wikipedia.org)
  • Local circuitry of identified projection neurons in cat visual cortex brain slices. (wikipedia.org)
  • receptive fields
  • Hubel, D., Wiesel, T.: Receptive fields and functional architecture in two nonstriate visual areas (18 and 19) of the cat. (springer.com)
  • Receptive fields have been identified for neurons of the auditory system, the somatosensory system, and the visual system. (wikipedia.org)
  • r e c e p t i v e f i e l d = c e n t e r + s u r r o u n d {\displaystyle receptive\ field=center+surround} In the visual system, receptive fields are volumes in visual space. (wikipedia.org)
  • In support of this theory is the experimental observation that the visual cortex neurons respond even more robustly to sine-wave gratings that are placed at specific angles in their receptive fields than they do to edges or bars. (wikipedia.org)
  • binocular
  • Up to 75% of subjects in some studies have strabismus (ocular misalignment), particularly esotropia, due to inherent subnormal binocular visual function and cognitive deficits in visuospatial construction. (wikipedia.org)
  • monkeys
  • We will then briefly compare the development and plasticity of extratriate cortex in monkeys with phenomena described for other mammalian groups. (springer.com)
  • One of the earliest reports on them was in 1964 using recordings of the electrical activity of electrodes implanted in the visual cortex of awake monkeys. (wikipedia.org)
  • spatial
  • A neural circuit for spatial summation in visual cortex. (biomedsearch.com)
  • To detect and follow analogous temporal and spatial events in human visual cortex, we used high-field functional MRI to map the progression of the BOLD events during migraine aura. (pnas.org)
  • The spatial-frequency theory refers to the theory that the visual cortex operates on a code of spatial frequency, not on the code of straight edges and lines hypothesised by Hubel and Wiesel on the basis of early experiments on V1 neurons in the cat. (wikipedia.org)
  • Research on spatial frequency detection by visual neurons complements and extends previous research using straight edges rather than refuting it. (wikipedia.org)
  • Mild to moderate intellectual disability with particular problems with visual spatial tasks such as drawing and fewer problems with language are typical. (wikipedia.org)
  • Individuals with Williams syndrome have problems with visual processing, but this is related to difficulty in dealing with complex spatial relationships rather than depth perception per se. (wikipedia.org)
  • This pattern is consistent with the visual-spatial disabilities and problems with behavioral timing often seen in Williams syndrome. (wikipedia.org)
  • stimulation
  • Repetitive, low-frequency stimulation (LFS) of either layer IV or the white matter of visual cortical slices was shown to result in a long- term depression (LTD) of intra- and extracellularly recorded synaptic responses in layer III. (jneurosci.org)
  • During periods with no visual stimulation, but while the subject was experiencing scintillations, BOLD signal followed the retinotopic progression of the visual percept. (pnas.org)
  • Electrical stimulation of the cortex at any point causes a muscle-contraction in the represented body part. (wikipedia.org)
  • contralateral
  • Each hemisphere's V1 receives information directly from its ipsilateral lateral geniculate nucleus that receives signals from the contralateral visual hemifield. (wikipedia.org)
  • Visual field defects (contralateral hemianopia with macular sparing). (wikipedia.org)
  • posterior
  • The dorsal stream begins with V1, goes through Visual area V2, then to the dorsomedial area (DM/ V6) and Visual area MT (middle temporal/ V5) and to the posterior parietal cortex . (wikipedia.org)
  • Experiments
  • In these experiments, participants read words whose visual forms were either predictable or unpredictable based on prior linguistic context or based on a recently seen picture. (wikipedia.org)
  • Experiments using visual cliffs have shown human infants and toddlers, as well as other animals of various ages, to be reluctant in venturing onto a glass floor with a view of a few meters of apparent fall-space below it. (wikipedia.org)
  • Subsequent experiments by many others demonstrated this phenomenon in a wide range of visual cognition. (wikipedia.org)
  • lateral
  • Visual information coming from the eye goes through the lateral geniculate nucleus in the thalamus and then reaches the visual cortex. (wikipedia.org)
  • Layer 4, which receives most visual input from the lateral geniculate nucleus (LGN), is further divided into 4 layers, labelled 4A, 4B, 4Cα, and 4Cβ. (wikipedia.org)
  • slices
  • Artola A, Bröcher S, Singer W (1990) Different voltage-dependent thresholds for inducing long-term depression and long-term potentiation in slices of rat visual cortex. (springer.com)
  • perception
  • More recently, Goodale and Milner extended these ideas and suggested that the ventral stream is critical for visual perception whereas the dorsal stream mediates the visual control of skilled actions. (wikipedia.org)
  • The next piece of the puzzle will be to understand what each of these projection motifs does for visual processing and perception and how these long-range connectivity patterns are established during development," Professor Mrsic-Flogel concluded. (ucl.ac.uk)
  • There are several types of perceptual constancies in visual perception: Size constancy is one type of visual subjective constancy. (wikipedia.org)
  • The result of poor distance constancy is that visual perception in schizophrenics is lacking in depth and that these patients live in a 'flatter' world. (wikipedia.org)
  • In the study of visual perception, sinusoidal gratings are frequently used to probe the capabilities of the visual system. (wikipedia.org)
  • When all of the visual cortex neurons that are influenced by a specific scene respond together, the perception of the scene is created by the summation of the various sine-wave gratings. (wikipedia.org)
  • mechanisms
  • According to a prominent theory, view information is represented by view-selective mechanisms at early stages of visual processing and gradually becomes view invariant in high-level visual areas. (jneurosci.org)
  • This uncertainty about the mechanisms of migraine visual aura has seriously limited the development of therapeutic drugs that could act directly on CSD. (pnas.org)
  • experimental
  • Binocularity in the visual system further permits experimental manipulations of a single eye input with the other eye serving as a useful internal reference point. (springer.com)
  • Involvement of bidirectional modification at excitatory synapses in experience-dependent cortical maturation has been supported by various experimental data in visual cortex. (springer.com)
  • In the eyetracking visual world paradigm, experimental subjects listen to a sentence while staring at an array of pictures on a computer monitor. (wikipedia.org)
  • vivo
  • Gorba T, Wahle P (1999) Expression of trkB and trkC but BDNF mRNA in neurochemically identified interneurons in rat visual cortex in vivo and in organotypic cultures. (springer.com)
  • synapses
  • This bidirectional modification at inhibitory synapses may contribute to the refinement and maintenance of visual responsiveness, and regulation of the critical period in visual cortex. (springer.com)