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Advanced Circuit and Cellular Imaging Methods in Nonhuman Primates

Stephen L. Macknik, Robert G. Alexander, Olivya Caballero, Jordi Chanovas, Kristina J. Nielsen, Nozomi Nishimura, Chris B. Schaffer, Hamutal Slovin, Amit Babayoff, Ravid Barak, Shiming Tang, Niansheng Ju (+4 others)
2019 Journal of Neuroscience  
and light-activated proteins that result in the visualization of tens of thousands of identified cortical neurons in NHPs.  ...  We describe a subset of the many recent advances in circuit and cellular imaging tools in NHPs focusing here primarily on the research presented during the corresponding mini-symposium at the 2019 Society  ...  Finally, to test whether V1 can be used for high-resolution readout of visual stimuli, Slovin group attempted to reconstruct, at sub-degree resolution, visual contours from the VSD signal that were evoked  ... 
doi:10.1523/jneurosci.1168-19.2019 pmid:31619496 pmcid:PMC6794937 fatcat:cdloqbzugjcold63qbchplxfgi

Measurement of population receptive fields in human early visual cortex using back-projection tomography

C. A. Greene, S. O. Dumoulin, B. M. Harvey, D. Ress
2014 Journal of Vision  
The signals produced by a set of bar sweeps encircling the visual field form a sinogram. pRFs were reconstructed from these sinograms with a novel scheme that corrects for the blur introduced by the hemodynamic  ...  the results using a predefined model shape for the pRF.  ...  (D) Estimated pRF reconstructed from the sinogram by weighted back projection. A contour was interpolated from the pRF at half maximum (dashed line).  ... 
doi:10.1167/14.1.17 pmid:24453343 fatcat:sdcmp6e62zfpldttya2vsrbb6q

The Representation of Illusory and Real Contours in Human Cortical Visual Areas Revealed by Functional Magnetic Resonance Imaging

Janine D. Mendola, Anders M. Dale, Bruce Fischl, Arthur K. Liu, Roger B. H. Tootell
1999 Journal of Neuroscience  
Two types of illusory contours differed in the strength of activation of the retinotopic areas, but both types activated crudely retinotopic visual areas, including V3A, V4v, V7, and V8, bilaterally.  ...  However, there were distinctive differences in the strength of activity across areas and contour types.  ...  For cortical inflating and flattening, the lower resolution f unctional data (3 ϫ 3 ϫ 4 mm) was smoothly interpolated onto the high-resolution surface reconstruction.  ... 
doi:10.1523/jneurosci.19-19-08560.1999 pmid:10493756 fatcat:mxfl2aowzfclvm734bhoynlh3a

Selective Activation of the Deep Layers of the Human Primary Visual Cortex by Top-Down Feedback

Peter Kok, Lauren J. Bains, Tim van Mourik, David G. Norris, Floris P. de Lange
2016 Current Biology  
activate deep layers of V1 d Bottom-up stimulus input activates all layers of V1  ...  Highlights d High-field fMRI can resolve neural activity with laminar specificity in humans d Top-down and bottom-up signals lead to distinct laminar activation profiles in V1 d Top-down signals selectively  ...  The institutional review board at Radboud Univeristy and the ethics committee of the University Duisburg-Essen approved the study.  ... 
doi:10.1016/j.cub.2015.12.038 pmid:26832438 fatcat:a3akl3levvcfvilynsu4wbsayu

Computations in the early visual cortex

Tai Sing Lee
2003 Journal of Physiology - Paris  
This paper reviews some of the recent neurophysiological studies that explore the variety of visual computations in the early visual cortex in relation to geometric inference, i.e. the inference of contours  ...  , surfaces and shapes.  ...  The author thanks many of his colleagues, in particular David Mumford, Peter Schiller, Carl Olson, Carol Colby, James McClelland, Gustavo Deco, Song-chun Zhu, Victor Lamme, My Nguyen, Cindy Yang, Rick  ... 
doi:10.1016/j.jphysparis.2003.09.015 pmid:14766138 fatcat:4r3aaqjy75edbacxw4cfabwd2y

Hierarchical Bayesian inference in the visual cortex

Tai Sing Lee, David Mumford
2003 Optical Society of America. Journal A: Optics, Image Science, and Vision  
Traditional views of visual processing suggest that early visual neurons in areas V1 and V2 are static spatiotemporal filters that extract local features from a visual scene.  ...  These new findings suggest that activity in the early visual cortex is tightly coupled and highly interactive with the rest of the visual system.  ...  ACKNOWLEDGMENTS Tai Sing Lee ( was supported by National Science Foundation CAREER grant 9984706 and National Institutes of Health grants MH64445 and  ... 
doi:10.1364/josaa.20.001434 pmid:12868647 fatcat:klq4xlrcyfehpnv5urrrncbphq

Differential Effect of Contrast Polarity Reversals in Closed Squares and Open L-Junctions

Mark M. Schira, Branka Spehar
2011 Frontiers in Psychology  
It has been shown that reversals in contrast polarity at points of highest orientation discontinuity along closed contours significantly impair shape discrimination performance, while changes in contrast  ...  Here we employ (semi) high resolution fMRI (1.5 mm x 1.5 mm x 1.5 mm) to investigate the neuronal substrate underlying these perception effects.  ...  The presence of contrast polarity reversals was only detrimental to shape discrimination performance when contrast polarity reversals were positioned at corners (or at points of high contour curvature  ... 
doi:10.3389/fpsyg.2011.00047 pmid:21716597 pmcid:PMC3110876 fatcat:eqy7rikyancilburo62qqq7xgm

Perceptual segregation of overlapping shapes activates posterior extrastriate visual cortex in man

Jonas Larsson, Katrin Amunts, Balázs Gulyás, Aleksandar Malikovic, Karl Zilles, Per E. Roland
2002 Experimental Brain Research  
The activation of this region of extrastriate visual cortex by a task that involved segregation of overlapping shapes is consistent with monkey V4 and human V4v being functionally homologous.  ...  The region activated by segregation of overlapping shapes was located in the posterior occipital cortex close to the anterior border of area V2, near the average location of human V4v as determined by  ...  Acknowledgements This study was supported by grants from the Swedish Medical Research Council, the Volvo Foundation, SFB 194/A6 (K. Zilles), and Biotech (P.E. Roland and K. Zilles).  ... 
doi:10.1007/s00221-001-0895-6 pmid:11907685 fatcat:au7oz5ygnjbdlhwscmaoksrpsi

Neural construction of 3D medial axis from the binocular fusion of 2D MAs

Wei Qiu, Yasuhiro Hatori, Ko Sakai
2015 Neurocomputing  
Computational studies have 58 shown that the MA response in V1 can be generated by simultaneous arrival of traveling 59 spikes that are initiated by nearby V1 cells [14] , or from onset synchronization  ...  Because the structure of skeletons is sensitive to the 65 direction of view (binocular difference) and noise in the contours, small changes in view and 66 contour dramatically alter the structure of skeleton  ...  2D MA to mimic the activities of V1 cells 529 responding to 2D MA.  ... 
doi:10.1016/j.neucom.2014.08.019 fatcat:vepcna724zfu5i65ttxhb27phq

Retinotopic activation in response to subjective contours in primary visual cortex

Marianne Maertens
2008 Frontiers in Human Neuroscience  
We measured a spatially precise spin-echo BOLD signal and found stronger responses to subjective shapes than non-shapes at the subjective boundary locations, but not at the inducer locations.  ...  We suggest that in the absence of retinal stimulation, the observed activation changes in primary visual cortex are driven by intracortical interactions and feedback, which are revealed in the absence  ...  In order to determine regions of interest, the functional data from the localizer scan were individually registered onto their corresponding high resolution anatomical data (1 × 1 × 1 mm) using FLIRT  ... 
doi:10.3389/neuro.09.002.2008 pmid:18958203 pmcid:PMC2525970 fatcat:hc7ykb42qnbe5gnbis6u3quc5i

The dynamics of contour integration: A simultaneous EEG–fMRI study

Bogdan Mijović, Maarten De Vos, Katrien Vanderperren, Bart Machilsen, Stefan Sunaert, Sabine Van Huffel, Johan Wagemans
2014 NeuroImage  
The stimuli were Gabor arrays with some Gabor elements positioned on the contour of an embedded shape, in three conditions: with local and global structure (perfect contour alignment), with global structure  ...  This component can be interpreted as being related to the verification of the consistency of the different local elements with the globally defined shape, which is necessary when perfect local-to-global  ...  Wagemans by longterm structural funding from the Flemish Government (METH/08/02).  ... 
doi:10.1016/j.neuroimage.2013.11.032 pmid:24269572 fatcat:sjklmlinorfibbryxjbfr6kate

Laminar analysis of 7T BOLD using an imposed spatial activation pattern in human V1

Jonathan R. Polimeni, Bruce Fischl, Douglas N. Greve, Lawrence L. Wald
2010 NeuroImage  
With sufficient image encoding, high-resolution fMRI studies are limited by the biological point-spread of the hemodynamic signal.  ...  In particular, large draining vessels on the cortical surface are a major contributor to both the BOLD signal change and to the spatial bias of the BOLD activation away from the site of neuronal activity  ...  White matter surface reconstruction is superimposed as yellow contour. Fig. 3 . 3 Laminar analysis of the fMRI activation.  ... 
doi:10.1016/j.neuroimage.2010.05.005 pmid:20460157 pmcid:PMC3130346 fatcat:rbcfiy57grdwrdm4xma3jq3w3a

Computerized Mappings of the Cerebral Cortex: A Multiresolution Flattening Method and a Surface-Based Coordinate System

Heather A. Drury, David C. Van Essen, Charles H. Anderson, Chris W. Lee, Thomas A. Coogan, James W. Lewis
1996 Journal of Cognitive Neuroscience  
The second stage reduces distortions using a multiresolution strategy that makes gross s1i;ipe changes on a co;irsely sampled map and further shape retinements on progressively finer resolution maps.  ...  We present a new method for generating two-dimensionnl maps of the cerebral cortex.  ...  Acknowledgments This work was supported by joint funding from NIMH, NASA, and NSF under the Human Brain Project MHIDA52158 and by NIH Grant EY02091. We thank S.  ... 
doi:10.1162/jocn.1996.8.1.1 pmid:11539144 fatcat:aiyqarm2rfapdb47oesgccim3u

Functional neuroimaging findings on the human perception of illusory contours

M.L. Seghier, P. Vuilleumier
2006 Neuroscience and Biobehavioral Reviews  
Illusory contours (IC) have attracted a considerable interest in recent years to derive models of how sensory information is processed and integrated within the visual system.  ...  In this paper, we review the results from more than 20 neuroimaging studies on IC perception and highlight the great diversity of findings across these studies.  ...  Acknowledgements This work was supported by grants from the Swiss National Science Foundation (No. 3200B0-100717 to MS; and No. 632.065935 to PV).  ... 
doi:10.1016/j.neubiorev.2005.11.002 pmid:16457887 fatcat:qahz6hzhkjdifk6capgkge2zeq

Sparse Approximation of Images Inspired from the Functional Architecture of the Primary Visual Areas

Sylvain Fischer, Rafael Redondo, Laurent Perrinet, Gabriel Cristóbal
2006 EURASIP Journal on Advances in Signal Processing  
The edge coefficients are shown sufficient for closely reconstructing the images, while contour representations by means of chains of edges reduce the information redundancy for approaching image compression  ...  Facing the difficulty to optimize such nonorthogonal and nonlinear transforms, we implement a sparse approximation scheme inspired from the functional architecture of the primary visual cortex.  ...  SF, RR and LP are supported by grants from MEC-FPU, CSIC-I3P and EC IP project FP6-015879," "FACETS," respectively.  ... 
doi:10.1155/2007/90727 fatcat:hn75sqmkzfdwpaxtfdyjhwv3oi
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