Psychophysical differences in processing of global motion and form detection and position discrimination.

In models of complex motion processing of expanding, contracting or rotating patterns, localization of the center of motion is regarded as an implicit function of the system, used for heading determination and achieved by coarse population encoding. The situation modeled contains an optic flow patte...

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Główni autorzy: Harvey, B, Braddick, O
Format: Journal article
Język:English
Wydane: 2008
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author Harvey, B
Braddick, O
author_facet Harvey, B
Braddick, O
author_sort Harvey, B
collection OXFORD
description In models of complex motion processing of expanding, contracting or rotating patterns, localization of the center of motion is regarded as an implicit function of the system, used for heading determination and achieved by coarse population encoding. The situation modeled contains an optic flow pattern that is modified by including translational motion, as occurs when the observer is not looking directly at their heading, and relies on global processing of the entire optic flow field. Our psychophysics experiments show that accurately localizing the center of a symmetrical complex motion pattern, or an analogous complex radial or concentric form pattern, relies on local processing near the center of the pattern. This contrasts with detection of the same patterns, which involves considerable spatial summation, relies on global processing, and is very tolerant of noisy stimuli. Coarse localization uses both central and peripheral information, involving some spatial summation. Some differences are seen between different pattern types. The low level of spatial summation seen in position discrimination is surprising if position discrimination is seen as an implicit function of the global processing system, and suggests modifications may be needed to models of heading determination.
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spelling oxford-uuid:f4539f5e-9488-4f7b-a848-3ef17a1df2a22022-03-27T12:19:01ZPsychophysical differences in processing of global motion and form detection and position discrimination.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:f4539f5e-9488-4f7b-a848-3ef17a1df2a2EnglishSymplectic Elements at Oxford2008Harvey, BBraddick, OIn models of complex motion processing of expanding, contracting or rotating patterns, localization of the center of motion is regarded as an implicit function of the system, used for heading determination and achieved by coarse population encoding. The situation modeled contains an optic flow pattern that is modified by including translational motion, as occurs when the observer is not looking directly at their heading, and relies on global processing of the entire optic flow field. Our psychophysics experiments show that accurately localizing the center of a symmetrical complex motion pattern, or an analogous complex radial or concentric form pattern, relies on local processing near the center of the pattern. This contrasts with detection of the same patterns, which involves considerable spatial summation, relies on global processing, and is very tolerant of noisy stimuli. Coarse localization uses both central and peripheral information, involving some spatial summation. Some differences are seen between different pattern types. The low level of spatial summation seen in position discrimination is surprising if position discrimination is seen as an implicit function of the global processing system, and suggests modifications may be needed to models of heading determination.
spellingShingle Harvey, B
Braddick, O
Psychophysical differences in processing of global motion and form detection and position discrimination.
title Psychophysical differences in processing of global motion and form detection and position discrimination.
title_full Psychophysical differences in processing of global motion and form detection and position discrimination.
title_fullStr Psychophysical differences in processing of global motion and form detection and position discrimination.
title_full_unstemmed Psychophysical differences in processing of global motion and form detection and position discrimination.
title_short Psychophysical differences in processing of global motion and form detection and position discrimination.
title_sort psychophysical differences in processing of global motion and form detection and position discrimination
work_keys_str_mv AT harveyb psychophysicaldifferencesinprocessingofglobalmotionandformdetectionandpositiondiscrimination
AT braddicko psychophysicaldifferencesinprocessingofglobalmotionandformdetectionandpositiondiscrimination