Decision ambiguity is mediated by a late positive potential originating from cingulate cortex
Sai Sun,
Shanshan Zhen,
Zhongzheng Fu,
Daw-An Wu,
Shinsuke Shimojo,
Ralph Adolphs,
Rongjun Yu,
Shuo Wang
Affiliations
Sai Sun
School of Psychology, Center for Studies of Psychological Application, and Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, South China Normal University, Guangzhou 510631, PR China
Shanshan Zhen
School of Psychology, Center for Studies of Psychological Application, and Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, South China Normal University, Guangzhou 510631, PR China; Department of Psychology, National University of Singapore, 117570, Singapore
Zhongzheng Fu
Department of Computing and Mathematical Sciences, California Institute of Technology, Pasadena, CA 91125, USA
Daw-An Wu
Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
Shinsuke Shimojo
Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
Ralph Adolphs
Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Humanities and Social Sciences, California Institute of Technology, Pasadena, CA 91125, USA
Rongjun Yu
School of Psychology, Center for Studies of Psychological Application, and Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, South China Normal University, Guangzhou 510631, PR China; Department of Psychology, National University of Singapore, 117570, Singapore; Corresponding author at: School of Psychology, Center for Studies of Psychological Application, and Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, South China Normal University, Guangzhou 510631, PR China.
Shuo Wang
Humanities and Social Sciences, California Institute of Technology, Pasadena, CA 91125, USA; Blanchette Rockefeller Neurosciences Institute, West Virginia University, Morgantown, WV 26505, USA; Corresponding author at: Blanchette Rockefeller Neurosciences Institute, West Virginia University, Morgantown, WV 26505, USA.
People often make decisions in the face of ambiguous information, but it remains unclear how ambiguity is represented in the brain. We used three types of ambiguous stimuli and combined EEG and fMRI to examine the neural representation of perceptual decisions under ambiguity. We identified a late positive potential, the LPP, which differentiated levels of ambiguity, and which was specifically associated with behavioral judgments about choices that were ambiguous, rather than passive perception of ambiguous stimuli. Mediation analyses together with two further control experiments confirmed that the LPP was generated only when decisions are made (not during mere perception of ambiguous stimuli), and only when those decisions involved choices on a dimension that is ambiguous. A further control experiment showed that a stronger LPP arose in the presence of ambiguous stimuli compared to when only unambiguous stimuli were present. Source modeling suggested that the LPP originated from multiple loci in cingulate cortex, a finding we further confirmed using fMRI and fMRI-guided ERP source prediction. Taken together, our findings argue for a role of an LPP originating from cingulate cortex in encoding decisions based on task-relevant perceptual ambiguity, a process that may in turn influence confidence judgment, response conflict, and error correction.
