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  • 1
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    Sparse coding and decorrelation in primary visual cortex during natural vision (2000)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2000-02-26
    Description: Theoretical studies suggest that primary visual cortex (area V1) uses a sparse code to efficiently represent natural scenes. This issue was investigated by recording from V1 neurons in awake behaving macaques during both free viewing of natural scenes and conditions simulating natural vision. Stimulation of the nonclassical receptive field increases the selectivity and sparseness of individual V1 neurons, increases the sparseness of the population response distribution, and strongly decorrelates the responses of neuron pairs. These effects are due to both excitatory and suppressive modulation of the classical receptive field by the nonclassical receptive field and do not depend critically on the spatiotemporal structure of the stimuli. During natural vision, the classical and nonclassical receptive fields function together to form a sparse representation of the visual world. This sparse code may be computationally efficient for both early vision and higher visual processing.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Vinje, W E -- Gallant, J L -- New York, N.Y. -- Science. 2000 Feb 18;287(5456):1273-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Program in Neuroscience, Department of Molecular and Cellular Biology, and Department of Psychology, University of California at Berkeley, Berkeley, CA 94720-1650, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/10678835" target="_blank"〉PubMed〈/a〉
    Keywords: Action Potentials ; Animals ; Evoked Potentials, Visual ; Fixation, Ocular ; Macaca mulatta ; Neurons/physiology ; Photic Stimulation ; Saccades ; Vision, Ocular/*physiology ; Visual Cortex/*physiology ; Visual Perception/*physiology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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  • 2
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    Identifying natural images from human brain activity (2008)
    Nature Publishing Group (NPG)
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    Publication Date: 2008-03-07
    Description: A challenging goal in neuroscience is to be able to read out, or decode, mental content from brain activity. Recent functional magnetic resonance imaging (fMRI) studies have decoded orientation, position and object category from activity in visual cortex. However, these studies typically used relatively simple stimuli (for example, gratings) or images drawn from fixed categories (for example, faces, houses), and decoding was based on previous measurements of brain activity evoked by those same stimuli or categories. To overcome these limitations, here we develop a decoding method based on quantitative receptive-field models that characterize the relationship between visual stimuli and fMRI activity in early visual areas. These models describe the tuning of individual voxels for space, orientation and spatial frequency, and are estimated directly from responses evoked by natural images. We show that these receptive-field models make it possible to identify, from a large set of completely novel natural images, which specific image was seen by an observer. Identification is not a mere consequence of the retinotopic organization of visual areas; simpler receptive-field models that describe only spatial tuning yield much poorer identification performance. Our results suggest that it may soon be possible to reconstruct a picture of a person's visual experience from measurements of brain activity alone.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3556484/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3556484/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kay, Kendrick N -- Naselaris, Thomas -- Prenger, Ryan J -- Gallant, Jack L -- R01 EY019684/EY/NEI NIH HHS/ -- England -- Nature. 2008 Mar 20;452(7185):352-5. doi: 10.1038/nature06713. Epub 2008 Mar 5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Psychology, University of California, Berkeley, California 94720, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18322462" target="_blank"〉PubMed〈/a〉
    Keywords: Brain/*physiology ; Brain Mapping/*methods ; Humans ; Image Processing, Computer-Assisted ; Magnetic Resonance Imaging ; Nature ; Photic Stimulation ; Photography ; Research Design ; Visual Perception/*physiology
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Published by Nature Publishing Group (NPG)
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  • 3
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    Selectivity for polar, hyperbolic, and Cartesian gratings in macaque visual cortex (1993)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1993-01-01
    Description: The neural basis of pattern recognition is a central problem in visual neuroscience. Responses of single cells were recorded in area V4 of macaque monkey to three classes of periodic stimuli that are based on spatial derivative operators: polar (concentric and radial), hyperbolic, and conventional sinusoidal (Cartesian) gratings. Of 118 cells tested, 16 percent responded significantly more to polar or hyperbolic (non-Cartesian) gratings than to Cartesian gratings and only 8 percent showed a significant preference for Cartesian gratings. Among cells selective for non-Cartesian gratings, those that preferred concentric gratings were most common. Cells selective for non-Cartesian gratings may constitute an important intermediate stage in pattern recognition and the representation of surface shape.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gallant, J L -- Braun, J -- Van Essen, D C -- EY02091/EY/NEI NIH HHS/ -- T32NS07251/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1993 Jan 1;259(5091):100-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Biology, California Institute of Technology, Pasadena 91125.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8418487" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Electroencephalography ; Macaca nemestrina ; Neurons/*physiology ; Pattern Recognition, Visual/*physiology ; Photic Stimulation ; Visual Cortex/*physiology ; Visual Fields/physiology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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  • 4
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    Natural speech reveals the semantic maps that tile human cerebral cortex (2016)
    Nature Publishing Group (NPG)
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    Publication Date: 2016-04-29
    Description: The meaning of language is represented in regions of the cerebral cortex collectively known as the 'semantic system'. However, little of the semantic system has been mapped comprehensively, and the semantic selectivity of most regions is unknown. Here we systematically map semantic selectivity across the cortex using voxel-wise modelling of functional MRI (fMRI) data collected while subjects listened to hours of narrative stories. We show that the semantic system is organized into intricate patterns that seem to be consistent across individuals. We then use a novel generative model to create a detailed semantic atlas. Our results suggest that most areas within the semantic system represent information about specific semantic domains, or groups of related concepts, and our atlas shows which domains are represented in each area. This study demonstrates that data-driven methods--commonplace in studies of human neuroanatomy and functional connectivity--provide a powerful and efficient means for mapping functional representations in the brain.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4852309/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4852309/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Huth, Alexander G -- de Heer, Wendy A -- Griffiths, Thomas L -- Theunissen, Frederic E -- Gallant, Jack L -- EY019684/EY/NEI NIH HHS/ -- R01 EY019684/EY/NEI NIH HHS/ -- England -- Nature. 2016 Apr 28;532(7600):453-8. doi: 10.1038/nature17637.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Helen Wills Neuroscience Institute, University of California, Berkeley, California 94720, USA. ; Department of Psychology, University of California, Berkeley, California 94720, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/27121839" target="_blank"〉PubMed〈/a〉
    Keywords: Adult ; Auditory Perception ; *Brain Mapping ; Cerebral Cortex/*anatomy & histology/*physiology ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Narration ; Principal Component Analysis ; Reproducibility of Results ; *Semantics ; *Speech
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Published by Nature Publishing Group (NPG)
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  • 5
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    Spatial frequency and orientation tuning dynamics in area V1 (2002)
    National Academy of Sciences
    Details
    Publication Date: 2002-01-29
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
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