Show simple item record

dc.contributor.authorSchmidtmann, Gen
dc.contributor.authorGordon, GEen
dc.contributor.authorBennett, DMen
dc.contributor.authorLoffler, Gen
dc.date.accessioned2017-11-16T17:25:34Z
dc.date.available2017-11-16T17:25:34Z
dc.date.issued2013en
dc.identifier.issn1662-5188en
dc.identifier.urihttp://hdl.handle.net/10026.1/10184
dc.description.abstract

The proportion of signal elements embedded in noise needed to detect a signal is a standard tool for investigating motion perception. This paradigm was applied to the shape domain to determine how local information is pooled into a global percept. Stimulus arrays consisted of oriented Gabor elements that sampled the circumference of concentric radial frequency (RF) patterns. Individual Gabors were oriented tangentially to the shape (signal) or randomly (noise). In different conditions, signal elements were located randomly within the entire array or constrained to fall along one of the concentric contours. Coherence thresholds were measured for RF patterns with various frequencies (number of corners) and amplitudes ("sharpness" of corners). Coherence thresholds (about 10% = 15 elements) were lowest for circular shapes. Manipulating shape frequency or amplitude showed a range where thresholds remain unaffected (frequency ≤ RF4; amplitude ≤ 0.05). Increasing either parameter caused thresholds to rise. Compared to circles, thresholds increased by approximately four times for RF13 and five times for amplitudes of 0.3. Confining the signals to individual contours significantly reduced the number of elements needed to reach threshold (between 4 and 6), independent of the total number of elements on the contour or contour shape. Finally, adding external noise to the orientation of the elements had a greater effect on detection thresholds than adding noise to their position. These results provide evidence for a series of highly sensitive, shape-specific analysers which sum information globally but only from within specific annuli. These global mechanisms are tuned to position and orientation of local elements from which they pool information. The overall performance for arrays of elements can be explained by the sensitivity of multiple, independent concentric shape detectors rather than a single detector integrating information widely across space (e.g. Glass pattern detector).

en
dc.format.extent37 - ?en
dc.languageengen
dc.language.isoengen
dc.subjectcontouren
dc.subjectformen
dc.subjectglobal shapeen
dc.subjectsignal integrationen
dc.subjecttextureen
dc.titleDetecting shapes in noise: tuning characteristics of global shape mechanisms.en
dc.typeJournal Article
plymouth.author-urlhttps://www.ncbi.nlm.nih.gov/pubmed/23720625en
plymouth.volume7en
plymouth.publication-statusPublished onlineen
plymouth.journalFront Comput Neuroscien
dc.identifier.doi10.3389/fncom.2013.00037en
plymouth.organisational-group/Plymouth
plymouth.organisational-group/Plymouth/00 Groups by role
plymouth.organisational-group/Plymouth/00 Groups by role/Academics
plymouth.organisational-group/Plymouth/Faculty of Health and Human Sciences
plymouth.organisational-group/Plymouth/Faculty of Health and Human Sciences/School of Health Professions
plymouth.organisational-group/Plymouth/Research Groups
plymouth.organisational-group/Plymouth/Research Groups/Institute of Health and Community
dc.publisher.placeSwitzerlanden
dcterms.dateAccepted2013-04-02en
dc.rights.embargoperiodNot knownen
rioxxterms.versionofrecord10.3389/fncom.2013.00037en
rioxxterms.licenseref.urihttp://www.rioxx.net/licenses/all-rights-reserveden
rioxxterms.licenseref.startdate2013en
rioxxterms.typeJournal Article/Reviewen


Files in this item

Thumbnail
Thumbnail

This item appears in the following Collection(s)

Show simple item record


All items in PEARL are protected by copyright law.
Author manuscripts deposited to comply with open access mandates are made available in accordance with publisher policies. Please cite only the published version using the details provided on the item record or document. In the absence of an open licence (e.g. Creative Commons), permissions for further reuse of content should be sought from the publisher or author.
Theme by 
@mire NV