{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/90853"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/90853","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"The role of crowding in parallel search","abstract":"Crowding is the deleterious effect of nearby objects on object recognition in the peripheral (Pelli, 2008). In three visual search experiments the contribution of visual crowding to reaction time performance in an efficient search task was evaluated by varying the factors known to affect the strength of crowding: spacing between objects and similarity. Traditionally, pop-out search is believed to isolate the first stage of visual processing and has been characterized as producing shallow search slopes (<10 ms/item), which are independent of set size. Recent results from our lab suggest discrimination pop-out search has a logarithmic relationship between reaction time and set size, which is modulated by the lure-target similarity (Buetti et al., in press). These results have been interpreted as resulting from the first stage of visual processing that is exhaustive, unlimited-in-capacity and resolution limited. Items sufficiently dissimilar to the target are rejected by stage-one processing, and items sufficiently similar to the target are inspected with focused attention. Here we ask if the limitation in resolution in stage-one processing is a result of crowding and evaluate the contribution of crowding to our previous logarithmic search slope findings. In three experiments reaction time performance was compared on two possible display types which differed in the spatial arrangements. The results from three experiments converge on the same pattern of results: reaction times increased logarithmically with set size and were modulated by lure-target similarity for both display types.","abstract_html":"Crowding is the deleterious effect of nearby objects on object recognition in the peripheral (Pelli, 2008). In three visual search experiments the contribution of visual crowding to reaction time performance in an efficient search task was evaluated by varying the factors known to affect the strength of crowding: spacing between objects and similarity. Traditionally, pop-out search is believed to isolate the first stage of visual processing and has been characterized as producing shallow search slopes (&lt;10 ms/item), which are independent of set size. Recent results from our lab suggest discrimination pop-out search has a logarithmic relationship between reaction time and set size, which is modulated by the lure-target similarity (Buetti et al., in press). These results have been interpreted as resulting from the first stage of visual processing that is exhaustive, unlimited-in-capacity and resolution limited. Items sufficiently dissimilar to the target are rejected by stage-one processing, and items sufficiently similar to the target are inspected with focused attention. Here we ask if the limitation in resolution in stage-one processing is a result of crowding and evaluate the contribution of crowding to our previous logarithmic search slope findings. In three experiments reaction time performance was compared on two possible display types which differed in the spatial arrangements. The results from three experiments converge on the same pattern of results: reaction times increased logarithmically with set size and were modulated by lure-target similarity for both display types.","abstract_has_math":false,"creators":["Madison, Anna M"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.A.","degree_level":"Thesis","degree_discipline":"Psychology","degree_department":null,"school":null,"contributors":["Buetti, Simona L","Lleras, Alejandro"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-07-07T20:35:30Z","date_published":"2016-07-07T20:35:30Z","updated_at":"2026-07-22T22:26:34Z","subjects":["efficient search","visual search","crowding"],"languages":["en"],"rights":["Copyright 2016 Anna Madison"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/90853","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Buetti, Simona L","Lleras, Alejandro"]},{"key":"dc:creator","label":"Author","values":["Madison, Anna M"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2016-07-07T20:35:30Z","2018-07-08T09:15:33Z","2016-04-29","2016-05"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Psychology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.A."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["efficient search","visual search","crowding"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2016 Anna Madison"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/90853"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Crowding is the deleterious effect of nearby objects on object recognition in the peripheral (Pelli, 2008). In three visual search experiments the contribution of visual crowding to reaction time performance in an efficient search task was evaluated by varying the factors known to affect the strength of crowding: spacing between objects and similarity. Traditionally, pop-out search is believed to isolate the first stage of visual processing and has been characterized as producing shallow search slopes (<10 ms/item), which are independent of set size. Recent results from our lab suggest discrimination pop-out search has a logarithmic relationship between reaction time and set size, which is modulated by the lure-target similarity (Buetti et al., in press). These results have been interpreted as resulting from the first stage of visual processing that is exhaustive, unlimited-in-capacity and resolution limited. Items sufficiently dissimilar to the target are rejected by stage-one processing, and items sufficiently similar to the target are inspected with focused attention. Here we ask if the limitation in resolution in stage-one processing is a result of crowding and evaluate the contribution of crowding to our previous logarithmic search slope findings. In three experiments reaction time performance was compared on two possible display types which differed in the spatial arrangements. The results from three experiments converge on the same pattern of results: reaction times increased logarithmically with set size and were modulated by lure-target similarity for both display types.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2018-05-01","The student, Anna Madison, accepted the attached license on 2016-04-29 at 14:52.","The student, Anna Madison, submitted this Thesis for approval on 2016-04-29 at 14:56.","This Thesis was approved for publication on 2016-04-29 at 15:16.","DSpace SAF Submission Ingestion Package generated from Vireo submission #9590 on 2016-07-07 at 13:51:14","Made available in DSpace on 2016-07-07T20:35:30Z (GMT). No. of bitstreams: 2 MADISON-THESIS-2016.pdf: 1985282 bytes, checksum: e30f5783e69c5239561e6a55132ec85f (MD5) LICENSE.txt: 4209 bytes, checksum: 171f172cda97f1bac01017a03cf461ff (MD5) Previous issue date: 2016-04-29","Embargo set by: Seth Robbins for item 93206 Lift date: 2018-07-07T20:35:34Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only Restriction Lifted for Item 93206 on 2018-07-08T09:15:33Z."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["The role of crowding in parallel search"]}]}],"canonical_facts":{"dc:contributor":["Buetti, Simona L","Lleras, Alejandro"],"dc:creator":["Madison, Anna M"],"dc:date":["2016-07-07T20:35:30Z","2018-07-08T09:15:33Z","2016-04-29","2016-05"],"dc:description":["Crowding is the deleterious effect of nearby objects on object recognition in the peripheral (Pelli, 2008). In three visual search experiments the contribution of visual crowding to reaction time performance in an efficient search task was evaluated by varying the factors known to affect the strength of crowding: spacing between objects and similarity. Traditionally, pop-out search is believed to isolate the first stage of visual processing and has been characterized as producing shallow search slopes (<10 ms/item), which are independent of set size. Recent results from our lab suggest discrimination pop-out search has a logarithmic relationship between reaction time and set size, which is modulated by the lure-target similarity (Buetti et al., in press). These results have been interpreted as resulting from the first stage of visual processing that is exhaustive, unlimited-in-capacity and resolution limited. Items sufficiently dissimilar to the target are rejected by stage-one processing, and items sufficiently similar to the target are inspected with focused attention. Here we ask if the limitation in resolution in stage-one processing is a result of crowding and evaluate the contribution of crowding to our previous logarithmic search slope findings. In three experiments reaction time performance was compared on two possible display types which differed in the spatial arrangements. The results from three experiments converge on the same pattern of results: reaction times increased logarithmically with set size and were modulated by lure-target similarity for both display types.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2018-05-01","The student, Anna Madison, accepted the attached license on 2016-04-29 at 14:52.","The student, Anna Madison, submitted this Thesis for approval on 2016-04-29 at 14:56.","This Thesis was approved for publication on 2016-04-29 at 15:16.","DSpace SAF Submission Ingestion Package generated from Vireo submission #9590 on 2016-07-07 at 13:51:14","Made available in DSpace on 2016-07-07T20:35:30Z (GMT). No. of bitstreams: 2 MADISON-THESIS-2016.pdf: 1985282 bytes, checksum: e30f5783e69c5239561e6a55132ec85f (MD5) LICENSE.txt: 4209 bytes, checksum: 171f172cda97f1bac01017a03cf461ff (MD5) Previous issue date: 2016-04-29","Embargo set by: Seth Robbins for item 93206 Lift date: 2018-07-07T20:35:34Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only Restriction Lifted for Item 93206 on 2018-07-08T09:15:33Z."],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/90853"],"dc:language":["en"],"dc:rights":["Copyright 2016 Anna Madison"],"dc:subject":["efficient search","visual search","crowding"],"dc:title":["The role of crowding in parallel search"],"dc:type":["text"],"thesis:degree_discipline":["Psychology"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.A."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:34Z"}