{"689228":{"#nid":"689228","#data":{"type":"event","title":"PhD Defense by Yunxuan Zheng","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003EName: Yunxuan Zheng\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ESchool of Psychology \u2013 Ph.D. Dissertation Defense Meeting\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EDate:\u003C\/strong\u003E\u0026nbsp;Wednesday, April 8th, 2026\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ETime:\u003C\/strong\u003E\u0026nbsp;10.30am - 12pm\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EZoom link:\u003C\/strong\u003E\u0026nbsp;\u003Ca href=\u0022https:\/\/gatech.zoom.us\/my\/yzheng447?omn=99368304690\u0022 target=\u0022_blank\u0022 title=\u0022https:\/\/gatech.zoom.us\/my\/yzheng447?omn=99368304690\u0022\u003Ehttps:\/\/gatech.zoom.us\/my\/yzheng447?omn=99368304690\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EDissertation Chair\/Advisor:\u003C\/strong\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EDobromir Rahnev, Ph.D. (Georgia Institute of Technology)\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EDissertation Committee Members:\u003C\/strong\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003ERick Thomas, Ph.D. (Georgia Institute of Technology)\u003C\/p\u003E\u003Cp\u003ERobert Wilson, Ph.D. (Georgia Institute of Technology)\u003C\/p\u003E\u003Cp\u003EJorge Morales, Ph.D. (Northeastern University)\u003Cbr\u003EBrian Odegaard, Ph.D. (University of Florida)\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ETitle: \u003C\/strong\u003E\u003Cem\u003E\u003Cstrong\u003EA common computational basis for perceptual decisions and metacognitive judgments\u003C\/strong\u003E\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EAbstract:\u003C\/strong\u003E\u003Cbr\u003EType-1 perceptual decision making refers to judging the identity of sensory stimuli, whereas Type-2 perceptual metacognition involves judging the accuracy of those decisions. A central question is whether these judgments are generated by the same cognitive system or by two distinct systems. This thesis addresses this issue through three experiments. In Study 1, we applied a computational model to data from a 2-alternative forced-choice and a discrimination task to separate sensory, decisional, and metacognitive noise. We confirmed decisional noise in Type-1 judgments beyond sensory noise, and identified additional metacognitive noise unique to Type-2 judgments. In Study 2, we manipulated expectation and reward structure in the Type-1 judgment to match its complexity with the Type-2 judgment. Under the conditions showing matched complexity, we found the noise magnitude in Type-1 and Type-2 judgments was also similar, suggesting that the extra metacognitive noise may be a product of task demands rather than a separate system. In Study 3, subjects further provided Type-3 judgments (certainty about their Type-2 judgments). We found that combining 2-point Type-2 and Type-3 scales was equivalent to a single 4-point confidence rating, with no evidence of additional computational noise in Type-3 judgments\u2014suggesting Type-2 and Type-3 judgments likely arise from the same system.\u0026nbsp;Together, these findings raise the possibility that perceptual decision making and metacognition may share a common computational basis and operate on the same underlying signals, challenging strong two-system accounts of cognitive architecture.\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003E\u003Cem\u003E\u003Cstrong\u003EA common computational basis for perceptual decisions and metacognitive judgments\u003C\/strong\u003E\u003C\/em\u003E\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"A common computational basis for perceptual decisions and metacognitive judgments"}],"uid":"27707","created_gmt":"2026-03-30 12:04:46","changed_gmt":"2026-03-30 12:05:28","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2026-04-08T10:30:00-04:00","event_time_end":"2026-04-08T12:00:00-04:00","event_time_end_last":"2026-04-08T12:00:00-04:00","gmt_time_start":"2026-04-08 14:30:00","gmt_time_end":"2026-04-08 16:00:00","gmt_time_end_last":"2026-04-08 16:00:00","rrule":null,"timezone":"America\/New_York"},"location":"ZOOM","extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}