Tolerance for local and global differences in the integration of shape information
© 2015 ARVO. Shape is a critical cue to object identity. In psychophysical studies, radial frequency (RF) patterns, paths deformed from circular by a sinusoidal modulation of radius, have proved valuable stimuli for the demonstration of global integration of local shape information. Models of the me...
| Main Authors: | , , , |
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| Format: | Journal Article |
| Language: | English |
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2015
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| Online Access: | http://purl.org/au-research/grants/arc/DP1097003 http://hdl.handle.net/20.500.11937/80930 |
| _version_ | 1848764291613720576 |
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| author | Dickinson, J.E. Cribb, S.J. Riddell, Hugh Badcock, D.R. |
| author_facet | Dickinson, J.E. Cribb, S.J. Riddell, Hugh Badcock, D.R. |
| author_sort | Dickinson, J.E. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | © 2015 ARVO. Shape is a critical cue to object identity. In psychophysical studies, radial frequency (RF) patterns, paths deformed from circular by a sinusoidal modulation of radius, have proved valuable stimuli for the demonstration of global integration of local shape information. Models of the mechanism of integration have focused on the periodicity in measures of curvature on the pattern, despite the fact that other properties covary. We show that patterns defined by rectified sinusoidal modulation also exhibit global integration and are indistinguishable from conventional RF patterns at their thresholds for detection, demonstrating some indifference to the modulating function. Further, irregular patterns incorporating four different frequencies of modulation are globally integrated, indicating that uniform periodicity is not critical. Irregular patterns can be handed in the sense that mirror images cannot be superimposed. We show that mirror images of the same irregular pattern could not be discriminated near their thresholds for detection. The same irregular pattern and a pattern with four cycles of a constant frequency of modulation completing 2p radians were, however, perfectly discriminated, demonstrating the existence of discrete representations of these patterns by which they are discriminated. It has previously been shown that RF patterns of different frequencies are perfectly discriminated but that patterns with the same frequency but different numbers of cycles of modulation were not. We conclude that such patterns are identified, near threshold, by the set of angles subtended at the center of the pattern by adjacent points of maximum convex curvature. |
| first_indexed | 2025-11-14T11:17:01Z |
| format | Journal Article |
| id | curtin-20.500.11937-80930 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | eng |
| last_indexed | 2025-11-14T11:17:01Z |
| publishDate | 2015 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-809302021-01-05T08:07:07Z Tolerance for local and global differences in the integration of shape information Dickinson, J.E. Cribb, S.J. Riddell, Hugh Badcock, D.R. detection discrimination form global integration radial frequency patterns shape threshold Adult Form Perception Humans Pattern Recognition, Visual Photic Stimulation Psychophysics Sensation Sensory Thresholds © 2015 ARVO. Shape is a critical cue to object identity. In psychophysical studies, radial frequency (RF) patterns, paths deformed from circular by a sinusoidal modulation of radius, have proved valuable stimuli for the demonstration of global integration of local shape information. Models of the mechanism of integration have focused on the periodicity in measures of curvature on the pattern, despite the fact that other properties covary. We show that patterns defined by rectified sinusoidal modulation also exhibit global integration and are indistinguishable from conventional RF patterns at their thresholds for detection, demonstrating some indifference to the modulating function. Further, irregular patterns incorporating four different frequencies of modulation are globally integrated, indicating that uniform periodicity is not critical. Irregular patterns can be handed in the sense that mirror images cannot be superimposed. We show that mirror images of the same irregular pattern could not be discriminated near their thresholds for detection. The same irregular pattern and a pattern with four cycles of a constant frequency of modulation completing 2p radians were, however, perfectly discriminated, demonstrating the existence of discrete representations of these patterns by which they are discriminated. It has previously been shown that RF patterns of different frequencies are perfectly discriminated but that patterns with the same frequency but different numbers of cycles of modulation were not. We conclude that such patterns are identified, near threshold, by the set of angles subtended at the center of the pattern by adjacent points of maximum convex curvature. 2015 Journal Article http://hdl.handle.net/20.500.11937/80930 10.1167/15.3.21 eng http://purl.org/au-research/grants/arc/DP1097003 http://purl.org/au-research/grants/arc/DP110104553 http://purl.org/au-research/grants/arc/DP130102580 http://creativecommons.org/licenses/by/4.0/ fulltext |
| spellingShingle | detection discrimination form global integration radial frequency patterns shape threshold Adult Form Perception Humans Pattern Recognition, Visual Photic Stimulation Psychophysics Sensation Sensory Thresholds Dickinson, J.E. Cribb, S.J. Riddell, Hugh Badcock, D.R. Tolerance for local and global differences in the integration of shape information |
| title | Tolerance for local and global differences in the integration of shape information |
| title_full | Tolerance for local and global differences in the integration of shape information |
| title_fullStr | Tolerance for local and global differences in the integration of shape information |
| title_full_unstemmed | Tolerance for local and global differences in the integration of shape information |
| title_short | Tolerance for local and global differences in the integration of shape information |
| title_sort | tolerance for local and global differences in the integration of shape information |
| topic | detection discrimination form global integration radial frequency patterns shape threshold Adult Form Perception Humans Pattern Recognition, Visual Photic Stimulation Psychophysics Sensation Sensory Thresholds |
| url | http://purl.org/au-research/grants/arc/DP1097003 http://purl.org/au-research/grants/arc/DP1097003 http://purl.org/au-research/grants/arc/DP1097003 http://hdl.handle.net/20.500.11937/80930 |