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Perceptual “Read-Out” of Conjoined Direction and Disparity Maps in Extrastriate Area MT
Cortical neurons are frequently tuned to several stimulus dimensions, and many cortical areas contain intercalated maps of multiple variables. Relatively little is known about how information is “read out” of these multidimensional maps. For example, how does an organism extract information relevant...
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Formato: | Texto |
Lenguaje: | English |
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Public Library of Science
2004
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC368171/ https://www.ncbi.nlm.nih.gov/pubmed/15024425 http://dx.doi.org/10.1371/journal.pbio.0020077 |
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author | DeAngelis, Gregory C Newsome, William T |
author_facet | DeAngelis, Gregory C Newsome, William T |
author_sort | DeAngelis, Gregory C |
collection | PubMed |
description | Cortical neurons are frequently tuned to several stimulus dimensions, and many cortical areas contain intercalated maps of multiple variables. Relatively little is known about how information is “read out” of these multidimensional maps. For example, how does an organism extract information relevant to the task at hand from neurons that are also tuned to other, irrelevant stimulus dimensions? We addressed this question by employing microstimulation techniques to examine the contribution of disparity-tuned neurons in the middle temporal (MT) visual area to performance on a direction discrimination task. Most MT neurons are tuned to both binocular disparity and the direction of stimulus motion, and MT contains topographic maps of both parameters. We assessed the effect of microstimulation on direction judgments after first characterizing the disparity tuning of each stimulation site. Although the disparity of the stimulus was irrelevant to the required task, we found that microstimulation effects were strongly modulated by the disparity tuning of the stimulated neurons. For two of three monkeys, microstimulation of nondisparity-selective sites produced large biases in direction judgments, whereas stimulation of disparity-selective sites had little or no effect. The binocular disparity was optimized for each stimulation site, and our result could not be explained by variations in direction tuning, response strength, or any other tuning property that we examined. When microstimulation of a disparity-tuned site did affect direction judgments, the effects tended to be stronger at the preferred disparity of a stimulation site than at the nonpreferred disparity, indicating that monkeys can selectively monitor direction columns that are best tuned to an appropriate conjunction of parameters. We conclude that the contribution of neurons to behavior can depend strongly upon tuning to stimulus dimensions that appear to be irrelevant to the current task, and we suggest that these findings are best explained in terms of the strategy used by animals to perform the task. |
format | Text |
id | pubmed-368171 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2004 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-3681712004-03-16 Perceptual “Read-Out” of Conjoined Direction and Disparity Maps in Extrastriate Area MT DeAngelis, Gregory C Newsome, William T PLoS Biol Research Article Cortical neurons are frequently tuned to several stimulus dimensions, and many cortical areas contain intercalated maps of multiple variables. Relatively little is known about how information is “read out” of these multidimensional maps. For example, how does an organism extract information relevant to the task at hand from neurons that are also tuned to other, irrelevant stimulus dimensions? We addressed this question by employing microstimulation techniques to examine the contribution of disparity-tuned neurons in the middle temporal (MT) visual area to performance on a direction discrimination task. Most MT neurons are tuned to both binocular disparity and the direction of stimulus motion, and MT contains topographic maps of both parameters. We assessed the effect of microstimulation on direction judgments after first characterizing the disparity tuning of each stimulation site. Although the disparity of the stimulus was irrelevant to the required task, we found that microstimulation effects were strongly modulated by the disparity tuning of the stimulated neurons. For two of three monkeys, microstimulation of nondisparity-selective sites produced large biases in direction judgments, whereas stimulation of disparity-selective sites had little or no effect. The binocular disparity was optimized for each stimulation site, and our result could not be explained by variations in direction tuning, response strength, or any other tuning property that we examined. When microstimulation of a disparity-tuned site did affect direction judgments, the effects tended to be stronger at the preferred disparity of a stimulation site than at the nonpreferred disparity, indicating that monkeys can selectively monitor direction columns that are best tuned to an appropriate conjunction of parameters. We conclude that the contribution of neurons to behavior can depend strongly upon tuning to stimulus dimensions that appear to be irrelevant to the current task, and we suggest that these findings are best explained in terms of the strategy used by animals to perform the task. Public Library of Science 2004-03 2004-03-16 /pmc/articles/PMC368171/ /pubmed/15024425 http://dx.doi.org/10.1371/journal.pbio.0020077 Text en Copyright: © 2004 DeAngelis and Newsome. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
spellingShingle | Research Article DeAngelis, Gregory C Newsome, William T Perceptual “Read-Out” of Conjoined Direction and Disparity Maps in Extrastriate Area MT |
title | Perceptual “Read-Out” of Conjoined Direction and Disparity Maps in Extrastriate Area MT |
title_full | Perceptual “Read-Out” of Conjoined Direction and Disparity Maps in Extrastriate Area MT |
title_fullStr | Perceptual “Read-Out” of Conjoined Direction and Disparity Maps in Extrastriate Area MT |
title_full_unstemmed | Perceptual “Read-Out” of Conjoined Direction and Disparity Maps in Extrastriate Area MT |
title_short | Perceptual “Read-Out” of Conjoined Direction and Disparity Maps in Extrastriate Area MT |
title_sort | perceptual “read-out” of conjoined direction and disparity maps in extrastriate area mt |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC368171/ https://www.ncbi.nlm.nih.gov/pubmed/15024425 http://dx.doi.org/10.1371/journal.pbio.0020077 |
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