| Population anisotropy in area MT explains a perceptual difference between near and far disparity motion segmentation. | |
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MedLine Citation:
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PMID: 21068268 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Segmentation of the visual scene into relevant object components is a fundamental process for successfully interacting with our surroundings. Many visual cues, including motion and binocular disparity, support segmentation, yet the mechanisms using these cues are unclear. We used a psychophysical motion discrimination task in which noise dots were displaced in depth to investigate the role of segmentation through disparity cues in visual motion stimuli (experiment 1). We found a subtle, but significant, bias indicating that near disparity noise disrupted the segmentation of motion more than equidistant far disparity noise. A control experiment showed that the near-far difference could not be attributed to attention (experiment 2). To account for the near-far bias, we constructed a biologically constrained model using recordings from neurons in the middle temporal area (MT) to simulate human observers' performance on experiment 1. Performance of the model of MT neurons showed a near-disparity skew similar to that shown by human observers. To isolate the cause of the skew, we simulated performance of a model containing units derived from properties of MT neurons, using phase-modulated Gabor disparity tuning. Using a skewed-normal population distribution of preferred disparities, the model reproduced the elevated motion discrimination thresholds for near-disparity noise, whereas a skewed-normal population of phases (creating individually asymmetric units) did not lead to any performance skew. Results from the model suggest that the properties of neurons in area MT are computationally sufficient to perform disparity segmentation during motion processing and produce similar disparity biases as those produced by human observers. |
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Authors:
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Finnegan J Calabro; Lucia M Vaina |
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Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural Date: 2010-11-10 |
Journal Detail:
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Title: Journal of neurophysiology Volume: 105 ISSN: 1522-1598 ISO Abbreviation: J. Neurophysiol. Publication Date: 2011 Jan |
Date Detail:
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Created Date: 2011-01-12 Completed Date: 2011-06-17 Revised Date: 2012-01-02 |
Medline Journal Info:
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Nlm Unique ID: 0375404 Medline TA: J Neurophysiol Country: United States |
Other Details:
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Languages: eng Pagination: 200-8 Citation Subset: IM |
Affiliation:
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Department of Biomedical Engineering, Boston University, 44 Cummington St., Boston, MA 02215, USA. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Anisotropy Distance Perception / physiology* Humans Models, Biological Motion Perception / physiology* Neurons / physiology Psychophysics Temporal Lobe / physiology* Young Adult |
| Grant Support | |
ID/Acronym/Agency:
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R01NS-064100/NS/NINDS NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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