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Disambiguating the roles of area V1 and the lateral occipital complex (LOC) in contour integration

Marina Shpaner, Sophie Molholm, Emmajane Forde, John J. Foxe
2013 NeuroImage  
Rather, the earliest effects were observed within the timeframe of the N1 component (160-200 msecs) and inverse source analysis pointed to principle generators in the lateral occipital complex (LOC) within  ...  The distribution of effects uncovered here is consistent with pooling of information in higher order cortical areas as the initial step in contour integration, and that this pooling occurs relatively late  ...  Acknowledgments This study was primarily supported by a grant from the U.S. National Institute of Mental Health (NIMH) to JJF and SM (RO1 -MH085322  ... 
doi:10.1016/j.neuroimage.2012.11.023 pmid:23201366 pmcid:PMC3872825 fatcat:qqv6ds2fczgxnhedihpbonrwq4

Responses in early visual areas to contour integration are context dependent

Cheng Qiu, Philip C. Burton, Daniel Kersten, Cheryl A. Olman
2016 Journal of Vision  
Coordination between V1 and V2 may play a major role in coherent structure perception, especially with complex scene organization.  ...  Six regions of interest (two regions, containing either the cortex representing the target or the background clutter, in each of areas V1, V2, and V3) were predefined using separate target versus background  ...  Grant, and M.-P. Schallmo for scanning assistance. We would also like to thank the reviewers for their  ... 
doi:10.1167/16.8.19 pmid:27366994 pmcid:PMC4946811 fatcat:ta3ggmas4fgvlmzqfmn7y4tjgy

Cue combination anisotropies in contour integration: The role of lower spatial frequencies

Malte Persike, Günter Meinhardt
2015 Journal of Vision  
The combination of local orientation collinearity and spatial frequency contrast in contour integration was studied in two experiments using a 2AFC contour detection and discrimination task.  ...  Cue combination anisotropies in contour integration: The role of lower spatial frequencies. Journal of Vision, 15(5):17, 1-16, http://www.journalofvision.org/content/15/5/17,  ...  Although initial accounts placed the association field in visual areas as early as V1, recent findings suggest the involvement of higher levels like the lateral occipital complex (LOC; Kourtzi & Huberle  ... 
doi:10.1167/15.5.17 pmid:26067535 fatcat:t5ckabxodff6hp5wsp4sw44eta

Illusory contours: a window onto the neurophysiology of constructing perception

Micah M. Murray, Christoph S. Herrmann
2013 Trends in Cognitive Sciences  
Seeing seems effortless, despite the need to segregate and integrate visual information that varies in quality, quantity, and location.  ...  Illusory contours (ICs):: perception of lines, forms, and volumes in the absence of physical support (e.g., luminance gradients).  ...  Neurosci. 30, 12978-12995 7 Stanley, D.A. and Rubin, N. (2003) fMRI activation in response to illusory contours and salient regions in the human lateral occipital complex.  ... 
doi:10.1016/j.tics.2013.07.004 pmid:23928336 fatcat:3c3wz54dqvaunlqi5bnjdwfv3y

Ventral stream hierarchy underlying perceptual organization in adolescents with autism

Laurie-Anne Sapey-Triomphe, Bart Boets, Lien Van Eylen, Ilse Noens, Stefan Sunaert, Jean Steyaert, Johan Wagemans
2020 NeuroImage: Clinical  
The brain patterns were generally similar in both groups, but the ASD group showed greater activation than TD participants in the middle occipital gyrus and lateral occipital complex when perceiving fully  ...  Five conditions displayed Gabor patterns (defined by texture and/or contour) with increasing levels of perceptual organization. In each condition, both groups showed similar abilities.  ...  Gabor patterns, Farah Martens and Hans Op de Beeck (KU Leuven) for providing us with a functional mask of LOC, and Susan Whitfield-Gabrieli (MIT) for initial advise on using the ART Artifact Detection  ... 
doi:10.1016/j.nicl.2020.102197 pmid:32014827 pmcid:PMC6997624 fatcat:e4ux32m3abcodif3htfzus2b2e

Perceptual Organization Impairment in Schizophrenia and Associated Brain Mechanisms: Review of Research from 2005 to 2010

S. M. Silverstein, B. P. Keane
2011 Schizophrenia Bulletin  
Preliminary data on drug effects on PO and on changes in response to treatment suggest that anomalies in PO may furnish a biomarker for the integrity of its associated biological mechanisms.  ...  All of this recent evidence allows for a clearer picture of the nature of the impairment and how it relates to broader aspects of brain and behavioral functioning in schizophrenia.  ...  The Authors have declared that there are no conflicts of interest in relation to the subject of this study.  ... 
doi:10.1093/schbul/sbr052 pmid:21700589 pmcid:PMC3122298 fatcat:6emqzsmueravrls7pw6nii62cm

Recognition Alters the Spatial Pattern of fMRI Activation in Early Retinotopic Cortex

P.-J. Hsieh, E. Vul, N. Kanwisher
2010 Journal of Neurophysiology  
Yet several recent results indicate that neural representations in early retinotopic cortex reflect not just the sensory properties of the image, but also the perceived size and brightness of image regions  ...  of object identity-also affects the representation of an object in early retinotopic cortex.  ...  This analysis was applied to three (independently defined) ROIs: the lateral occipital complex (LOC); the foveal confluence (FC), an early retinotopic area at the occipital pole where the foveal representations  ... 
doi:10.1152/jn.00812.2009 pmid:20071627 pmcid:PMC3257064 fatcat:gx6tukyj4zf7pmfffwezgw3j6q

V3A Processes Contour Curvature as a Trackable Feature for the Perception of Rotational Motion

Gideon P. Caplovitz, Peter U. Tse
2006 Cerebral Cortex  
We found that the blood oxygen level--dependent signal in retinotopic area V3A and possibly also lateral occipital cortex (LOC) varied parametrically with the degree of CC.  ...  Contour curvature (CC) is a vital cue for the analysis of both form and motion.  ...  Individual Lateral Occipital Complex Masks An individual LOC mask was also determined individually for the same subjects for whom individual hMT+ masks were made following standard procedures (Kourtzi  ... 
doi:10.1093/cercor/bhl029 pmid:16831857 fatcat:e3viyik7tfbkhgg5kjsblisepy

V3A processes contour curvature as a trackable feature for the perception of rotational motion

P. U. Tse, G. P. Caplovitz
2010 Journal of Vision  
We found that the blood oxygen level--dependent signal in retinotopic area V3A and possibly also lateral occipital cortex (LOC) varied parametrically with the degree of CC.  ...  Contour curvature (CC) is a vital cue for the analysis of both form and motion.  ...  Individual Lateral Occipital Complex Masks An individual LOC mask was also determined individually for the same subjects for whom individual hMT+ masks were made following standard procedures (Kourtzi  ... 
doi:10.1167/6.6.578 fatcat:dgwm33kdprfn5ppbsa44ymg6ta

Extrastriate cortical activity reflects segmentation of motion into independent sources

G. Caplovitz, P. Tse
2011 Journal of Vision  
We find that BOLD signal in V3v, V4v, V3A, V3B and MT varies with the number of distinct sources of motion information in the visual scene.  ...  Here we apply fMRI to investigate the mechanisms underlying the segmentation and integration of motion signals that are critical to motion perception in general.  ...  Localizing the lateral occipital complex (LOC) Individual LOC masks were made following standard procedures (Kourtzi & Kanwisher, 2000a) .  ... 
doi:10.1167/11.11.724 fatcat:vz6rgjydszdrfhzezgw7pxgbme

Extrastriate cortical activity reflects segmentation of motion into independent sources

Gideon P. Caplovitz, Peter U. Tse
2010 Neuropsychologia  
We find that BOLD signal in V3v, V4v, V3A, V3B and MT varies with the number of distinct sources of motion information in the visual scene.  ...  Here we apply fMRI to investigate the mechanisms underlying the segmentation and integration of motion signals that are critical to motion perception in general.  ...  Localizing the lateral occipital complex (LOC) Individual LOC masks were made following standard procedures (Kourtzi & Kanwisher, 2000a) .  ... 
doi:10.1016/j.neuropsychologia.2010.05.017 pmid:20478319 fatcat:2xojos4gtbe5nn24mwbnlweabq

How Close Are We to Understanding V1?

Bruno A. Olshausen, David J. Field
2005 Neural Computation  
In particular, we identify five problems with the current view of V1 that stem largely from experimental and theoretical biases, in addition to the contributions of nonlinearities in the cortex that are  ...  In this review, rather than stating what is known, we attempt to estimate how much is still unknown about V1 function.  ...  Many of the ideas in this review were first developed in Olshausen, B. A., & Field, D. J. (2005). In T. J. Sejnowski & L. van Hemmen (Eds.), Twenty-three problems in systems neuroscience.  ... 
doi:10.1162/0899766054026639 pmid:15969914 fatcat:jwyzuic4tvf5tdw6fktwj36ysm

Object Perception: Generative Image Models and Bayesian Inference [chapter]

Daniel Kersten
2002 Lecture Notes in Computer Science  
Humans perceive object properties such as shape and material quickly and reliably despite the complexity and objective ambiguities of natural images.  ...  The visual system does this by integrating prior object knowledge with critical image features appropriate for each of a discrete number of tasks.  ...  The lateral occipital complex (LOC) is a higher level object processing area that has received considerable recent attention [18, 11] .  ... 
doi:10.1007/3-540-36181-2_21 fatcat:qna36b6rybb2lcqprprnnkdwdi

Early Stages of Figure–Ground Segregation during Perception of the Face–Vase

Michael A. Pitts, Antígona Martínez, James B. Brewer, Steven A. Hillyard
2011 Journal of Cognitive Neuroscience  
In Experiment 2, subjects selectively attended to the face or vase region, and the same early ERP components were again produced.  ...  In Experiment 3, subjects performed an identical selective attention task, but on a display lacking distinctive figure-ground borders, and neither of the early components were produced.  ...  supported by the Center for Biomedical Imaging (CIBM) of Geneva and Lausanne.  ... 
doi:10.1162/jocn.2010.21438 pmid:20146604 pmcid:PMC3071650 fatcat:qltwtidcqvgptireii46xvcv5i

Scene complexity modulates degree of feedback activity during object detection in natural scenes

Iris I. A. Groen, Sara Jahfari, Noor Seijdel, Sennay Ghebreab, Victor A. F. Lamme, H. Steven Scholte, Samuel J. Gershman
2018 PLoS Computational Biology  
First, functional magnetic resonance imaging (fMRI) activity in early visual cortex (V1) was enhanced for target objects in scenes with high, but not low or medium complexity.  ...  variation in the EEG feedback response.  ...  Acknowledgments We thank Anne Urai for helpful discussions on the HDDM analyses. Author Contributions  ... 
doi:10.1371/journal.pcbi.1006690 pmid:30596644 pmcid:PMC6329519 fatcat:dgov4xc7rbfd3pf4h22a3lmlhm
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