Events
Past Event
WED@NICO SEMINAR: Lightning Talks with NU Scholars!
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
May 20th Speakers:
Yulin Yu, Postdoctoral Fellow, Kellogg School of Management
Feihong Xu, PhD Candidate, McCormick School of Engineering
Maalvika Bhat, PhD Student, School of Communication
Rochana Chaturvedi, Postdoctoral Fellow, Kellogg School of Management
NICO Lightning talks are open to Northwestern graduate students, postdoctoral fellows, and visiting scholars! If you are interested in signing up for a future session, please fill out this short survey.
Talk Titles and Abstracts:
Yulin Yu
Postdoctoral Fellow
Kellogg School of Management &
Northwestern Institute on Complex Systems
Human–AI Creative Pathways: How People and Machines Differ in Creative Strategy
Generative AI offers the promise of amplifying creativity by recombining knowledge at a scale far beyond human capacity, yet humans still hold key advantages in flexibility and contextual reasoning. To understand how each achieves novelty, we analyzed more than 5,000 responses to the Divergent Association Task from both humans and AI systems using network-based methods. We find that while individual humans use fewer and simpler conceptual categories than machines, the collective diversity of human ideas is substantially higher. Human creative pathways tend to follow a one-directional but highly unpredictable trajectory, whereas AI systems rely on repetitive, back-and-forth exploration patterns. Finally, both humans and machines show anchoring effects—early ideas shape later responses—but in opposite ways: humans anchor low, while machines anchor high.
Feihong Xu
PhD Candidate
Engineering Sciences & Applied Mathematics
McCormick School of Engineering
A Well-Calibrated Model Similarity Measure for Arbitrary Neural Networks
Deep learning approaches have transformed biological and biomedical image analysis, but model opacity and fragility remain major obstacles to trustworthy use. One barrier is the lack of a well-calibrated measure of similarity across arbitrary neural networks trained with different architectures, checkpoints, random initializations, and training strategies. Existing notions of model similarity span functional and representational domains, often rely on heuristic assumptions, and are susceptible to spurious signals introduced by probing samples, making principled cross-model meta-analysis difficult. Here, we clarify prevailing notions of deep neural network similarity and benchmark their robustness under extensive out-of-distribution perturbations. We then introduce the Ahmad RV coefficient on chain weight matrices (wARV), a theoretically grounded weight-space similarity measure that combines chain-normalized weights with the RV coefficient. wARV is sample-agnostic, symmetric, computationally efficient, and better calibrated than current measures. Across benchmarks varying random initialization, training checkpoint, architecture, and training strategy, wARV more faithfully tracks functional similarity while avoiding confounding effects from probing data. Applying wARV to deep neural network models on both generic and medical image classification tasks, we uncover substantial learning heterogeneity and instability even among models with similar predictive performance.
Maalvika Bhat
PhD Student
Technology and Social Behavior
School of Communication &
McCormick School of Engineering
Scholars See Clickbait as a Greater Threat to Science Than to Their Own Work
As scientific research competes for attention in a media landscape driven by sensationalism, the risks of misrepresentation grow. This study examines whether academics, while widely recognizing clickbait as a threat to science broadly, tend to downplay its relevance to their own work. Surveying 5,603 U.S.-based researchers, we find a consistent perception gap between systemic and personal risk, one that varies by career stage and disciplinary context. Early-career scholars show a pronounced version of this asymmetry: they express heightened concern about clickbait’s harms to science while rating its relevance to their own work as comparatively lower, a pattern that leaves them most exposed at a stage when reputational stakes are highest.
Rochana Chaturvedi
Postdoctoral Fellow
Kellogg School of Management &
Northwestern Institute on Complex Systems
Who Gets the Callback? Generative Artificial Intelligence and Gender Bias
Large language models are increasingly embedded in hiring workflows, raising concerns about their potential to amplify societal biases — yet how these biases manifest within and across occupations, and the role of model 'personality' in shaping these biases, remains unexplored. We introduce a three-part attribution framework applied to 332,044 real-world job ads, measuring gender-based callback bias, associations of skills and traits with gendered stereotypes in LLMs, and the effect of simulated recruiter personas. We find that LLMs systematically favor men, especially in higher-wage roles, with their decisions tracking traditional gendered language cues in job postings. Notably, assigning a low-agreeableness persona reduces model bias, implicating sycophancy as a mechanism reinforcing societal stereotypes; at the same time, controversial personas trigger internal guardrails leading to more cautious and less-biased outputs. These findings highlight how alignment choices in AI-driven hiring systems shape bias, with important implications for fairness and diversity.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/98031689779
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, networks, and artificial intelligence. It brings together attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern, from applied math to sociology to biology and every discipline in-between. Please visit: https://bit.ly/WedatNICO for information on future speakers.
Time
Wednesday, May 20, 2026 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Timothy Tangherlini, UC Berkeley "Chat Agents, Conspiracy Theory & Threat Narratives: Cultural Analytics and Narrative at Scale"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
//
Lower Level, Chambers Hall
Details
Speaker:
Timothy Tangherlini, Elizabeth H. and Eugene A. Shurtleff Chair in Undergraduate Education, Distinguished Professor in the Dept. of Scandinavian and the School of Information, University of California, Berkeley
Title:
Chat Agents, Conspiracy Theory & Threat Narratives: Cultural Analytics and Narrative at Scale
Abstract:
In this talk, I present current work on the intersection of conspiracy theory and narratives of threat, with the shifting terrain of chat bots increasingly influencing the social media ecosystem. I present a generative model of narratives of threat, explore aspects of stance detection and the narrative sorting of actants and institutions into "insiders" and "outsiders." I then explore the topology of conspiracy theory as a narrative predilection for a comprehensive explanation of allegedly witnessed or experienced phenomena along with inferences about connections based on a monologic world view. Using examples from earlier political social media discussions, and updating these observations in the context of contemporaneous debates about the role of AI in society allow for insight into the thicket of connections that characterize the ongoing negotiation of belief through narrative
Speaker Bio:
Timothy R. Tangherlini, Elizabeth H. and Eugene A. Shurtleff Chair of Undergraduate Education, is a Distinguished Professor in the Dept. of Scandinavian and the School of Information at the University of California, Berkeley. He is also associate director of the Berkeley Institute for Data Science and the Faculty Director of the Berkeley Folklore Archive. He has worked on computational approaches to folklore, with an emphasis on stories and storytelling over the past three decades. Under the auspices of the NSF's Institute for Pure and Applied Mathematics, he co-directed a program on Culture Analytics, as well as an NEH Institute on Network Analysis for the Humanities. He is the author of several books, and various articles. He has done extensive fieldwork on storytelling among paramedics, and shamanism in South Korea, as well as archival work on rural 19th century Denmark. His current work focuses on generative models of common story genres such as legend, rumor, personal experience narratives, and conspiracy theories, as well as understanding cultural phenomena such as dance and cuisine across many scales of analysis.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/95645191725
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, networks, and artificial intelligence. It brings together attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern, from applied math to sociology to biology and every discipline in-between. Please visit: https://bit.ly/WedatNICO for information on future speakers.
Time
Wednesday, October 14, 2026 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Andreia Sofia Teixeira, Northeastern University London "Human Relational Ecology and Conversational AI: From Social Actor to Asymmetric Co-Regulation"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
//
Lower Level, Chambers Hall
Details
Speaker:
Andreia Sofia Teixeira, Associate Professor, Network Science Institute, Northeastern University London
Title:
Human Relational Ecology and Conversational AI: From Social Actor to Asymmetric Co-Regulation
Abstract:
Human cognition, mental health and relationships unfold within interconnected social systems that change over time. Drawing on work on cognitive-affective structure, the evolution of supportive and conflictual ties in adolescent social networks, and distinct social envirotypes associated with mental health and context-dependent patterns of brain connectivity, I will discuss what these different perspectives tell us about the human relational ecology in which wellbeing is embedded, including the role of co-regulation in shaping emotion, cognition and behaviour.
Understanding this ecology is especially important as conversational AI emerges as a new kind of social actor. These systems can simulate some of the interactional signals associated with co-regulation, including responsiveness, validation, emotional language and apparent empathy, but without reciprocal lived experience, vulnerability, embodiment or shared accountability. I will introduce the concept of asymmetric co-regulation to frame this distinction.
Building on emerging work at the intersection of AI use, social networks and real-world human–AI conversations, I will ask what happens when conversational AI moves beyond instrumental use and starts to occupy more relational roles: when it may scaffold or substitute for existing human capacities and forms of support, how repeated interactions may shape regulation and sense of agency over time, and how these dynamics may become embedded within wider social relationships.
Speaker Bio:
Andreia Sofia Teixeira is an Associate Professor at the Network Science Institute, Northeastern University London, where she leads the BRAN Lab (Behavioral Research and Adaptive Networks). Her research sits at the intersection of network science and machine learning, developing measures, computational models and simulation frameworks to understand the structure and dynamics of complex systems, and how local behaviour can spill over to collective scales. Her work spans human–AI interaction, collective behaviour, cognitive and affective networks, signed and temporal social networks, mental health and neuropsychiatric and neurodegenerative disorders. Across these areas, she is particularly interested in how individual states, relationships and broader social environments shape one another over time.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/98367624907
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, networks, and artificial intelligence. It brings together attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern, from applied math to sociology to biology and every discipline in-between. Please visit: https://bit.ly/WedatNICO for information on future speakers.
Time
Wednesday, October 21, 2026 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Rafael Prieto-Curiel, Complexity Science Hub Vienna "Why Incarcerating Cartel Members has not Worked to Reduce their Violence"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Rafael Prieto-Curiel, Faculty Member, Complexity Science Hub Vienna
Title:
Why Incarcerating Cartel Members has not Worked to Reduce their Violence
Abstract:
Organised crime cartels must largely be analysed as black boxes because direct observation is rarely possible, and available evidence consists mostly of imperfect proxies and very limited data. I will present complex systems models to quantify recruitment and incarceration to analyse the effect of organised criminals in Mexico. The results suggest that incarcerating cartel members has minor effects on reducing cartel violence, even with harsher punishment or longer sentences.
Speaker Bio:
Rafael Prieto-Curiel is a Faculty Member at the Complexity Science Hub, working on violence, mobility, migration and urban dynamics. He works for the OECD and the World Bank, where he does a spatial and demographic analysis of cities. He is the Scientific Advisor of Aleph.
He was awarded the “Science Breakthrough” award by the Falling Walls Foundation in 2024.
Before, he was at the Mathematical Institute of the University of Oxford / UCL CASA, working on urban dynamics at the Peak Urban project. He earned an MSc in Statistics and a PhD in Maths and Security and Crime at University College London (UCL).
He worked in the Emergency Attention Centre from Mexico City (C5) as Director of Strategic Analysis. His work consisted basically of crime forecasting and police and resource allocation.
Rafael is very interested in science communication. When he was an undergraduate student, he directed Laberintos e Infinitos, a maths magazine. When he started his PhD at UCL, he founded Chalkdust, a mathematics magazine. He also founded Punto Decimal MX, a science communication website. In total, he has published 11 editions of a maths magazine, with nearly 30,000 printed copies and edited nearly 500 articles by more than 200 authors.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/94858847147
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, networks, and artificial intelligence. It brings together attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern, from applied math to sociology to biology and every discipline in-between. Please visit: https://bit.ly/WedatNICO for information on future speakers.
Time
Wednesday, October 28, 2026 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Hamsa Bastani, University of Pennsylvania "Challenges in Achieving Human-AI Collaboration"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Hamsa Bastani, Associate Professor of Operations, Information, and Decisions, and Statistics and Data Science, Wharton School, University of Pennsylvania
Title:
Challenges in Achieving Human-AI Collaboration
Abstract:
TBA
Speaker Bio:
Hamsa Sridhar Bastani is an Associate Professor of Operations, Information, and Decisions (OID) and Statistics and Data Science at the Wharton School of the University of Pennsylvania, where she co-direct the Wharton Healthcare Analytics Lab. Her research sits at the intersection of machine learning, operations research, and economics. She studies how to design, deploy, and evaluate AI systems that empower human decision-makers and improve societal outcomes.
Professor Bastani aims to combine methodological depth with implementation in consequential environments. She has worked with national governments to deploy algorithms at the country scale for targeted border COVID-19 screening and essential medicine access, and has co-led one of the first large field studies of generative AI tutors in high school mathematics. She studies both the mathematical properties of algorithms and the way people respond to them.
Her research has been published in leading outlets including Nature, Management Science, Operations Research, and PNAS, and has garnered numerous recognitions, including the Wagner Prize for Excellence in Operations Research, the INFORMS Pierskalla Award for best healthcare paper, and the George Nicholson Prize. Previously, she graduated summa cum laude from Harvard in 2012 with an A.M. in physics and an A.B. in physics and mathematics, completed her PhD in Stanford's Electrical Engineering department under the supervision of Mohsen Bayati, and spent a year as a Herman Goldstine postdoctoral fellow at IBM Research.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/91360427929
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, networks, and artificial intelligence. It brings together attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern, from applied math to sociology to biology and every discipline in-between. Please visit: https://bit.ly/WedatNICO for information on future speakers.
Time
Wednesday, November 4, 2026 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Mayank Agrawal, Proof of Human "The Invisible Turing Test for the Internet"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
//
Lower Level, Chambers Hall
Details
Speaker:
Mayank Agrawal, Co-founder and CEO, Proof of Human
Title:
Proof of Human: the Invisible Turing Test for the Internet
Abstract:
This presentation introduces the Process Turing Test, a new framework for distinguishing humans from AI that goes beyond linguistic output to analyze behavioral dynamics. As LLMs routinely pass text-based Turing Tests, we need methods that probe the underlying architecture of intelligence through perception, control, and decision-making patterns. Using process tracing data from canonical cognitive tasks, we demonstrate how behavioral embeddings capture computational signatures unique to human cognition. This provides robust proof-of-personhood that resists adversarial attacks while revealing fundamental principles about how humans and machines process information differently.
Speaker Bio:
Mayank Agrawal is the co-founder and CEO of Proof of Human, a research and deployment company building the proof-of-human layer in digital identity. The company develops high-impact research and translates that work into systems for bot detection, fraud prevention, and continuous authentication. Mayank’s work focuses on new approaches to distinguishing humans from AI through behavioral and cognitive signals. He earned his PhD in Psychology and Neuroscience from Princeton University, where he studied computational models of human decision-making with Jonathan Cohen, Tom Griffiths, and Nathaniel Daw. His research spans cognitive science, machine learning, and artificial intelligence, with work published in Science, PNAS, and Psychological Review. He previously studied Computer Science and Philosophy at Swarthmore College.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/96392420891
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, networks, and artificial intelligence. It brings together attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern, from applied math to sociology to biology and every discipline in-between. Please visit: https://bit.ly/WedatNICO for information on future speakers.
Time
Wednesday, November 11, 2026 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)