Events
Past Event
WED@NICO SEMINAR: Cristian Huepe, Northwestern University "Online opinions and interactions regarding Covid-19 vaccinations: a Complex Systems analysis"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
//
Lower Level, Chambers Hall
Details
Speaker:
Cristian Huepe - Adjunct Professor, Engineering Sciences & Applied Mathematics (ESAM), Northwestern University, and External Faculty, Northwestern Institute on Complex Systems (NICO)
Title:
Online opinions and interactions regarding Covid-19 vaccinations: a Complex Systems analysis
Abstract:
Digital social networks can significantly affect Covid-19 vaccination campaigns, if well-connected conversations emerge that discourage immunization. Although the information in these platforms could help understand and manage the communities and narratives that influence vaccination, it has rarely been used to help evaluate or guide public health policy.
I will present an interdisciplinary study in which we analyzed all Chilean tweets related to the Covid-19 vaccines and vaccination process produced during a period of 6 months, to examine quantitatively and qualitatively the structure and dynamics of their opinions and interactions in a society that achieved high levels of immunization while experiencing substantial sociopolitical conflict. We trained a machine learning algorithm to score the tweeting accounts from the most pro-vaccine to the most anti-vaccine. We show that four categories with distinct tweeting practices and connectivity naturally emerge: pro-vaccine activists, anti-vaccine activists, and moderates that promote or inhibit vaccination in discussions, which also play a key role. Accounts disfavoring vaccination tend to appear in the periphery of the interaction network, consistent with Chile’s high immunization levels, but are more active in addressing those favoring vaccination than vice-versa, which reveals a potential problem in communication policy. Our results highlight the importance of social networks and online interventions for successful immunization campaigns.
Speaker Bio:
CHuepeLabs develops research in complex systems, nonequilibrium physical dynamics and quantitative social sciences. Current efforts focus on collective motion, active matter, complex networks, modular-hierarchical evolutionary structures, and opinion formation.
CHuepeLabs is a global research team centered on the work of Cristián Huepe in Chicago and at NICO (Northwestern Institute on Complex Systems) & ESAM (Applied Math Dept.) at Northwestern University (USA). CHuepeLabs also include collaborative teams at the School of Systems Science of Beijing Normal University (China), the Middle East Technical University ODTÜ/METU (Turkey), and the Social Listening Lab SoL-UC (Chile).
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/92818942739
Passcode: NICO22
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems and data science. 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 9, 2022 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
Data Science Nights - MAY 2026 - Speaker: Xudong Tang, Computer Science and NICO
Northwestern Institute on Complex Systems (NICO)
5:30 PM
//
M416, Technological Institute
Details
MAY MEETING: Thursday, May 28, 2026 at 5:30pm (US Central)
LOCATION:
ESAM Conference Room, Tech M416
2145 Sheridan Road, Evanston, IL 60208
AGENDA:
5:30pm - Meet and greet with refreshments
6:00pm - Talk with Xudong Tang, PhD Student, Computer Science, NICO, and the Human-AI Collaboration Lab, Northwestern University
TALK TITLE:
Human and Machine Perception of Voice Similarity
ABSTRACT:
Modern voice cloning systems generate synthetic speech that listeners frequently cannot identify as being synthetic. But a voice can sound natural without sounding like the intended person, and what determines whether a clone is heard as a particular person is an open question. Here we report a large-scale preregistered experiment in which we collected 92,239 responses from 175 participants on their perception of pairs of real recordings, voice clones, and continuously morphed voices drawn from 100 contemporary celebrities across 20 speaker groups. We find that voice clones do not reliably preserve perceived speaker identity, reducing same-speaker judgments by 12.7 percentage points even though the clones are produced by a state-of-the-art text-to-speech model, while leaving different-speaker judgments unchanged. Using continuously morphed stimuli, we find that speakers vary substantially in how much variation their perceived identity tolerates, and that this variation is not predicted by speaker demographics. Speaker embeddings account for 58.9\% (95\% CI = [55.7, 61.9]) of variance in identity judgments, which is more than acoustic features, social attributes, and clone status combined. Once all these observed features are accounted for, clone status adds no additional predictive power. These results shows that the perceptual impact of voice cloning is positional rather than categorical: we can model how listeners judge a voice by how close it falls to the perceptual boundary that defines each speaker's recognizable voice, applying the same criterion to real and synthetic speech alike.
DATA SCIENCE NIGHTS are monthly meetings featuring presentations and discussions about data-driven science and complex systems, organized by Northwestern University graduate students and scholars. Students and researchers of all levels are welcome! For more information: http://bit.ly/nico-dsn
FUTURE DATES:
Data Science Nights will return in September!
Time
Thursday, May 28, 2026 at 5:30 PM - 7:00 PM
Location
M416, Technological Institute Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
Spring 2026 Commencement
University Academic Calendar
All Day
Details
Spring 2026 Commencement
Time
Sunday, June 14, 2026
Contact
Calendar
University Academic Calendar
Juneteenth - University Closed
University Academic Calendar
All Day
Details
Juneteenth - University Closed
Time
Friday, June 19, 2026
Contact
Calendar
University Academic Calendar
Independence Day (observed) - University Closed
University Academic Calendar
All Day
Details
Independence Day (observed) - University Closed
Time
Friday, July 3, 2026
Contact
Calendar
University Academic Calendar
Fall 2026 Classes Begin
University Academic Calendar
All Day
Details
Fall 2026 Classes Begin
Time
Wednesday, September 23, 2026
Contact
Calendar
University Academic Calendar