About

Prof. Hyeongrak 'Chuck' Choi's research focuses on quantum engineering and photonics, including scalable and fault-tolerant quantum networks with photonic integrated circuits, solid-state quantum computing with spins in solids and CMOS technology, quantum magnetometers for navigation, entanglement-assisted non-local sensing, and visible photonic integrated circuits with extreme light-matter interaction.

Research topics

• Political Science
• Social psychology
• Cognitive psychology
• Psychology
• Developmental psychology
• Neuroscience
• Psychiatry
• Psychoanalysis
• Medicine

Selected publications

• Collaborative recall changes the global organization of memory: A representational similarity analysis of social influences on individual and collective memory organization.

  Journal of Experimental Psychology General · 2025-03-20 · 1 citations

  articleOpen access

  The last 25 years of research have revealed that recalling the past with others changes memory. A key finding is that former group members show increased memory overlap or collective memory. Beyond memory content, we ask whether collaborative recall changes the organization of memory. How we organize information has far-reaching consequences on learning and remembering, and research has produced sophisticated theories and measures of memory organization when people recall alone. However, research remains sparse on how social influences shape memory organization. Furthermore, studies document local changes only (small segments in recall), raising the question whether collaboration produces global changes (positional relations among all items) in memory organization that can inform how people construct memory narratives. It is also unclear whether collaboration affects memory organization differently for different emotional contents despite the well-established influence of emotion on memory. We address these questions by focusing on two important advances. Using representational similarity analysis, we seek a deeper understanding of collaborative recall on memory organization at the global level and how emotional valence influences memory organization. Comparing two collaborative recall sequences, collaborative-collaborative-individual and individual-collaborative-individual, with individual-individual-individual (baseline sequence), we replicated better memory for emotional than neutral content and collective memory for content. Novel to our aims, collaborative recall changed global memory organization, both at individual and collective levels and for neutral and emotional contents. These quantitative indices for holistic changes in memory organization reveal the depth of social influences in reshaping memory, with implications for remembering, beliefs, education, and national narratives. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

  PublisherDOI

• Collective memory and fluency tasks: Leveraging network analysis for a richer understanding of collective cognition.

  Canadian Journal of Experimental Psychology/Revue canadienne de psychologie expérimentale · 2024-12-30 · 2 citations

  articleOpen access

  in adjacent positions) are made at similar rates as well. Together, these complementary approaches suggest a striking stability in both what people recall and their ordering, providing a window into the composition of collective memories. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

  PublisherDOI

• Collaborative Recall and the Construction of Collective Memory Organization: The Impact of Group Structure

  Topics in Cognitive Science · 2023 · 17 citations

  • Political Science
  • Psychology
  • Social psychology

  Collaborative recall synchronizes downstream individual retrieval processes, giving rise to collective organization. However, little is known about whether particular stimulus features (e.g., semantic relatedness) are necessary for constructing collective organization and how group dynamics (e.g., reconfiguration) moderates it. We leveraged novel quantitative measures and a rich dataset reported in recent articles to address, (a) whether collective organization emerges even for semantically unrelated material and (b) how group reconfiguration-changing partners from one recall to the next-influences collective organization. Participants studied unrelated words and completed three consecutive recalls in one of three conditions: Always recalling individually (III), collaborating with the same partners twice before recalling alone (CCI), or collaborating with different group members during two initial recalls, before recalling alone (CRI). Collective organization increased significantly following any collaboration (CCI or CRI), relative to "groups" who never collaborated (III). Interestingly, collaborating repeatedly with the same partners (CCI) did not increase collective organization compared to reconfigured groups, irrespective of the reference group structure (from Recall 1 or 2). Individuals, however, did tend to base their final individual retrieval on the most recent group recall. We discuss how the fundamental processes that underlie dynamic social interactions align the cognitive processes of many, laying the foundation for other collective phenomena, including shared biases, attitudes, and beliefs.

  PublisherOA PDFDOI

• Neural correlates of anxiety under interrogation in guilt or innocence contexts

  PLoS ONE · 2020 · 1 citations

  • Psychology
  • Neuroscience
  • Cognitive psychology

  Interrogation elicits anxiety in individuals under scrutiny regardless of their innocence, and thus, anxious responses to interrogation should be differentiated from deceptive behavior in practical lie detection settings. Despite its importance, not many empirical studies have yet been done to separate the effects of interrogation from the acts of lying or guilt state. The present fMRI study attempted to identify neural substrates of anxious responses under interrogation in either innocent or guilt contexts by developing a modified "Doubt" game. Participants in the guilt condition showed higher brain activations in the right central-executive network and bilateral basal ganglia. Regardless of the person's innocence, we observed higher activation of the salience, theory of mind and sensory-motor networks-areas associated with anxiety-related responses in the interrogative condition, compared to the waived conditions. We further explored two different types of anxious responses under interrogation-true detection anxiety in the guilty (true positive) and false detection anxiety in the innocent (false positive). Differential neural responses across these two conditions were captured at the caudate, thalamus, ventral anterior cingulate and ventromedial prefrontal cortex. We conclude that anxiety is a common neural response to interrogation, regardless of an individual's innocence, and that there are detectable differences in neural responses for true positive and false positive anxious responses under interrogation. The results of our study highlight a need to isolate complex cognitive processes involved in the deceptive acts from the emotional and regulatory responses to interrogation in lie detection schemes.

  PublisherOA PDFDOI

• Optimization and classification of developmental brain diseases using machine learning of functional brain networks

  IBRO Reports · 2019-09-01

  articleOpen access
  PublisherDOI

• Mnemonic transmission, social contagion, and emergence of collective memory: Influence of emotional valence, group structure, and information distribution.

  Journal of Experimental Psychology General · 2017-06-08 · 52 citations

  articleOpen access1st authorCorresponding

  Social transmission of memory and its consequence on collective memory have generated enduring interdisciplinary interest because of their widespread significance in interpersonal, sociocultural, and political arenas. We tested the influence of 3 key factors-emotional salience of information, group structure, and information distribution-on mnemonic transmission, social contagion, and collective memory. Participants individually studied emotionally salient (negative or positive) and nonemotional (neutral) picture-word pairs that were completely shared, partially shared, or unshared within participant triads, and then completed 3 consecutive recalls in 1 of 3 conditions: individual-individual-individual (control), collaborative-collaborative (identical group; insular structure)-individual, and collaborative-collaborative (reconfigured group; diverse structure)-individual. Collaboration enhanced negative memories especially in insular group structure and especially for shared information, and promoted collective forgetting of positive memories. Diverse group structure reduced this negativity effect. Unequally distributed information led to social contagion that creates false memories; diverse structure propagated a greater variety of false memories whereas insular structure promoted confidence in false recognition and false collective memory. A simultaneous assessment of network structure, information distribution, and emotional valence breaks new ground to specify how network structure shapes the spread of negative memories and false memories, and the emergence of collective memory. (PsycINFO Database Record

  PublisherDOI

• Effects of Inhalable Microparticles of Seonpyejeongcheon-Tang in an Asthma Mouse Model - Effects of Microparticles of SJT -

  Journal of pharmacopuncture · 2016-12-29 · 5 citations

  articleOpen access

  Objectives: Allergic asthma generally presents with symptoms of wheezing, coughing, breathlessness, and airway inflammation. Seonpyejeongcheon-tang (SJT) consists of 12 herbs. It originated from Jeong-cheon-tang (JT), also known as Ding-chuan-tang, composed of 7 herbs, in She-sheng-zhong-miao-fang. This study aimed to evaluate the effects of local delivery of SJT via inhalable microparticles in an asthma mouse model. Methods: Microparticles containing SJT were produced by spray-drying with leucine as an excipient. SJT microparticles were evaluated with respect to their aerodynamic properties, in vitro cytotoxicity, in vivo toxicity, and therapeutic effects on ovalbumin (OVA)-induced asthma in comparison with orally-administered SJT. Results: SJT microparticles provided desirable aerodynamic properties (fine particle fraction of <TEX>$48.9%{\pm}6.4%$</TEX> and mass median aerodynamic diameter of <TEX>$3.7{\pm}0.3{\mu}m$</TEX>). SJT microparticles did not show any cytotoxicity against RAW 264.7 macrophages at concentrations of 0.01 - 3 mg/mL. Inhaled SJT microparticles decreased the levels of IL-4, IL-5, IL-13, IL-17A, eotaxin and OVA-IgE in bronchoalveolar lavage fluid (BALF) in mice with OVA-induced asthma. These effects were verified by histological evaluation of the levels of infiltration of inflammatory cells and collagen, destructions of alveoli and bronchioles, and hyperplasia of goblet cells in lung tissues. The effects of SJT microparticles in the asthma model were equivalent to those of orally-administered SJT extract. Conclusion: This study suggests that SJT is a promising agent for inhalation therapy for patients with asthma.

  PublisherOA PDFDOI

• How social interactions affect emotional memory accuracy: Evidence from collaborative retrieval and social contagion paradigms

  Memory & Cognition · 2016-02-23 · 36 citations

  articleOpen access

  In daily life, emotional events are often discussed with others. The influence of these social interactions on the veracity of emotional memories has rarely been investigated. The authors (Choi, Kensinger, & Rajaram Memory and Cognition, 41, 403-415, 2013) previously demonstrated that when the categorical relatedness of information is controlled, emotional items are more accurately remembered than neutral items. The present study examined whether emotion would continue to improve the accuracy of memory when individuals discussed the emotional and neutral events with others. Two different paradigms involving social influences were used to investigate this question and compare evidence. In both paradigms, participants studied stimuli that were grouped into conceptual categories of positive (e.g., celebration), negative (e.g., funeral), or neutral (e.g., astronomy) valence. After a 48-hour delay, recognition memory was tested for studied items and categorically related lures. In the first paradigm, recognition accuracy was compared when memory was tested individually or in a collaborative triad. In the second paradigm, recognition accuracy was compared when a prior retrieval session had occurred individually or with a confederate who supplied categorically related lures. In both of these paradigms, emotional stimuli were remembered more accurately than were neutral stimuli, and this pattern was preserved when social interaction occurred. In fact, in the first paradigm, there was a trend for collaboration to increase the beneficial effect of emotion on memory accuracy, and in the second paradigm, emotional lures were significantly less susceptible to the "social contagion" effect. Together, these results demonstrate that emotional memories can be more accurate than nonemotional ones even when events are discussed with others (Experiment 1) and even when that discussion introduces misinformation (Experiment 2).

  PublisherOA PDFDOI

• The Social Transmission of Emotional Memory

  PsycEXTRA Dataset · 2014-01-01

  dataset1st authorCorresponding

  People frequently reminisce about emotional occurrences with others in social settings. Past research has shown the benefits and costs of emotional or social influences on individual memory, but less is known about the interactive effects of these two factors. This dissertation research aimed to investigate the retrieval and transmission of emotional and nonemotional information by examining 1) how social interaction via group collaboration shapes one’s and a group’s memory for emotional information, 2) how shared or the absence of shared experiences among group members differentially affects the transmission of emotional memory. In Experiment 1, participants studied emotional (negative or positive) and nonemotional (neutral) pictures with words. Next, they completed three consecutive recall sessions either individually or in groups of three in one of three conditions: Individual-Individual-Individual (Control), Individual-Collaborative-Individual, and Collaborative-Collaborative-Individual. The results showed that the memory enhancement effects of emotional information observed in individual memory carries into group memory as well as into post-collaborative individual memory. It was also found that collaboration boosted post-collaborative individual recall of negative information to a greater extent than it did for positive information. In Experiment 2, participants completed three consecutive recall sessions in one of three conditions: Individual–Individual–Individual (Control), Collaborative–Collaborative (Identical group)–Individual, and Collaborative–Collaborative (Reconfigured group)–Individual. When individuals recalled the stimuli alone repeatedly, the memory enhancement effect of emotion was attenuated, illustrating the contributions of a more exhaustive retrieval effort. However, when people repeatedly retrieved emotional memory with others in groups, the memory enhancement effect of emotion was reinforced and boosted, especially for negative information. Finally, people remembered more negative information than positive information mainly when the information was shared with other group members, and did so more when they were asked to recall information with the same group of people, compared to a different group of people. Together, these findings converge to show that the retrieval and spread of emotional memory largely depends on whether the remembering of emotional experiences occurs in social or non-social context, as well as on whether such experiences are shared or unshared. | People frequently reminisce about emotional occurrences with others in social settings. Past research has shown the benefits and costs of emotional or social influences on individual memory, but less is known about the interactive effects of these two factors. This dissertation research aimed to investigate the retrieval and transmission of emotional and nonemotional information by examining 1) how social interaction via group collaboration shapes one’s and a group’s memory for emotional information, 2) how shared or the absence of shared experiences among group members differentially affects the transmission of emotional memory. In Experiment 1, participants studied emotional (negative or positive) and nonemotional (neutral) pictures with words. Next, they completed three consecutive recall sessions either individually or in groups of three in one of three conditions: Individual-Individual-Individual (Control), Individual-Collaborative-Individual, and Collaborative-Collaborative-Individual. The results showed that the memory enhancement effects of emotional information observed in individual memory carries into group memory as well as into post-collaborative individual memory. It was also found that collaboration boosted post-collaborative individual recall of negative information to a greater extent than it did for positive information. In Experiment 2, participants completed three consecutive recall sessions in one of three conditions: Individual–Individual–Individual (Control), Collaborative–Collaborative (Identical group)–Individual, and Collaborative–Collaborative (Reconfigured group)–Individual. When individuals recalled the stimuli alone repeatedly, the memory enhancement effect of emotion was attenuated, illustrating the contributions of a more exhaustive retrieval effort. However, when people repeatedly retrieved emotional memory with others in groups, the memory enhancement effect of emotion was reinforced and boosted, especially for negative information. Finally, people remembered more negative information than positive information mainly when the information was shared with other group members, and did so more when they were asked to recall information with the same group of people, compared to a different group of people. Together, these findings converge to show that the retrieval and spread of emotional memory largely depends on whether the remembering of emotional experiences occurs in social or non-social context, as well as on whether such experiences are shared or unshared. | 87 pages

  PublisherDOI

• The role of group configuration in the social transmission of memory: Evidence from identical and reconfigured groups

  Journal of Cognitive Psychology · 2013-12-03 · 43 citations

  article1st authorCorresponding

  Collaborating with others during recall shapes both group and individual memories. Individuals contribute less when recalling in groups than when recalling alone, a phenomenon called collaborative inhibition. In contrast, collaboration improves post-collaborative individual memory by providing re-exposure to information that would have been otherwise forgotten. Collaboration also influences collective memory—the overlap in post-collaborative memory among group members. We examined the role of group configuration on such transmission of memory by varying group configuration across repeated recalls. Participants (N = 162) studied words and completed three recall sessions in one of three conditions (N = 54/condition): Individual–Individual–Individual (Control), Collaborative–Collaborative (Identical group)–Individual and Collaborative–Collaborative (Reconfigured group)–Individual. Collaborative inhibition occurred in both the Identical and Reconfigured groups during the first recall but disappeared in the Reconfigured groups during the second recall. Post-collaborative individual memory was greater following Reconfigured than Identical group collaboration. This pattern reversed for collective memories; repeated collaboration increased overlap in the remembered and forgotten items in Identical groups compared to Reconfigured groups. Finally, Reconfigured groups provided a quantifiable index of the influence of distal partners (i.e., no direct collaboration involved) on post-collaborative individual memory. We conclude that group configuration has powerful consequences on the amount, the similarity and the variety of memory representations.

  PublisherDOI

Frequent coauthors

• Elizabeth A. Kensinger

  Boston College

  6 shared

• Hae‐Jeong Park

  Yonsei University

  5 shared

• Sole Yoo

  Yonsei University

  5 shared

• Suparna Rajaram

  Stony Brook University

  5 shared

• Hanseul H. Choi

  Yonsei University

  4 shared

• Suparna Rajaram

  3 shared

• Hyunseok Bahng

  Yonsei University

  3 shared

• Haeil Park

  Catholic University of Korea

  2 shared

Labs

• Quantum Engineering & PhotonicsPI

  Quantum computing, networking, sensing, and photonics