Document Detail


Extrastriate cortical activity reflects segmentation of motion into independent sources.
MedLine Citation:
PMID:  20478319     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Identical local image motion signals can arise from countless object motions in the world. In order to resolve this ambiguity, the visual system must somehow integrate motion signals arising from different locations along an object's contour. Difficulties arise, however, because image contours can derive from multiple objects and from occlusion. Thus, correctly integrating respective objects' motion signals presupposes the specification of what counts as an object. Depending on how this form analysis problem is solved, dramatically different object motion percepts can be constructed from the same set of local image motions. Here we apply fMRI to investigate the mechanisms underlying the segmentation and integration of motion signals that are critical to motion perception in general. We hold the number of image objects constant, but vary whether these objects are perceived to move independently or not. 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. These data support the hypothesis that these areas integrate form and motion information in order to segment motion into independent sources (i.e. objects) thereby overcoming ambiguities that arise at the earliest stages of motion processing.
Authors:
Gideon P Caplovitz; Peter U Tse
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Publication Detail:
Type:  Journal Article     Date:  2010-05-15
Journal Detail:
Title:  Neuropsychologia     Volume:  48     ISSN:  1873-3514     ISO Abbreviation:  Neuropsychologia     Publication Date:  2010 Jul 
Date Detail:
Created Date:  2010-07-12     Completed Date:  2010-10-20     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0020713     Medline TA:  Neuropsychologia     Country:  England    
Other Details:
Languages:  eng     Pagination:  2699-708     Citation Subset:  IM    
Copyright Information:
Copyright (c) 2010 Elsevier Ltd. All rights reserved.
Affiliation:
Princeton Neuroscience Institute, 3-N-13 Green Hall, Princeton University, Princeton, NJ 08544, United States. gcaplovi@princeton.edu
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MeSH Terms
Descriptor/Qualifier:
Brain Mapping*
Cerebral Cortex / blood supply,  physiology*
Female
Fixation, Ocular / physiology
Form Perception / physiology*
Humans
Image Processing, Computer-Assisted / methods
Linear Models
Magnetic Resonance Imaging / methods
Male
Motion Perception / physiology*
Oxygen / blood
Photic Stimulation / methods
Time Factors
Visual Pathways / blood supply,  physiology
Chemical
Reg. No./Substance:
7782-44-7/Oxygen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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