Speaker:

Raissa D'Souza, Professor and Associate Dean for Research, College of Engineering, University of California, Davis

Title:

Complex Networks with Complex Nodes: Emergent Behaviors and Control

Abstract:

Real world networks -- from brain networks to social networks to critical infrastructure networks -- are composed of nodes with nonlinear behaviors coupled together via highly non-trivial network structures. Approaches from statistical physics reveal the fundamental implications that complex network structure has on network function and resilience. In contrast, approaches from dynamical systems and control theory reveal the impact that nonlinear nodal dynamics have on emergent behaviors when connected together in simple networks. This talk presents recent work bridging the fields. We show that the interaction between the nodal dynamics and network structure can give rise to novel emergent synchronization behaviors and extend the analysis of cluster synchronization to hypergraphs, capturing higher-order interactions in networks. With respect to cascading failures, we show that adding in oscillatory nodal dynamics to classic models of self-organized-criticality leads to an emergent timescale and the occurrence of self-amplifying dragon king failures that wipe out the system. Finally, we discuss the frontiers of control of complex networks with non-linear nodes, identifying the key challenges and opportunities for bridging control theory, dynamical systems and statistical physics.

Speaker Bio:

Raissa D'Souza uses the tools of statistical physics and applied mathematics to develop mathematical models capturing the interplay between the structure and function of networks, including dynamical processes unfolding on networks. Her focus is on the abrupt onset of large-scale connectivity in networks, network synchronization behaviors and models of cascading failure. The general principles derived provide insights into the behaviors of real-world networks such as infrastructure networks and social networks, and opportunities to identify small interventions to control the self-organizing, collective behaviors displayed in these systems. She collaborates broadly with faculty within the college and in physics, statistics, political science and the Primate Center.

Location:

In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/92514761999
Passcode: NICO2023

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.

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Speaker:

Satoru Suzuki, Professor, Department of Pychology, Northwestern University

Title:

Some simple rules governing macroscopic oscillatory neural activity in humans

Abstract:

Oscillatory neural activity is ubiquitous, potentially contributing to neural communications via frequency channels. Extensive research has related oscillatory activities in specific frequency bands and regions to performing specific behavioral functions such as attentional selection, working memory, episodic memory, decision making, motor control, and so on. Our recent EEG-based research focused on a complementary goal of discovering simple rules that may govern the global dynamics of oscillatory neural activity. I will discuss some of the rules we have identified so far, such as: (1) Macroscopic oscillatory synchronizations may change relatively slowly while maintaining maximum entropy on the seconds timescale, (2) Maximal and minimal synchronizations may occur in spatially complementary small-scale and large-scale networks, (3) The global phase organization of oscillatory activities may be controlled by phase reversals in the long-distance frontal-occipital network, and (4) Alpha-band oscillations spontaneously frequency-converge along the frontal-occipital axis, mediated by synergistic interactions, potentially enhancing information flows to and from occipital regions. These simple rules may provide useful macroscopic constraints on computational models. Given that our results are observational, future research is necessary to understand how these rules may contribute to cognition and the maintenance of adaptive, responsive, and/or metastable neural dynamics.

Speaker Bio:

Satoru Suzuki is a Professor and the Director of Graduate Studies at Northwestern’s Department of Psychology. A major goal of his research has been to understand the cortical mechanisms that enable people to perceive coherent global forms from retinal illumination patterns that are often ambiguous as to what meaningful forms and configurations are present. He has used psychophysical paradigms, recently combined with computational modeling, that allow for parametric comparisons of behavioral results with known physiological properties of visual neurons. His research provides insights into the ultimate questions of (1) how neural activity throughout the ventral visual stream generates a seemingly coherent and unitary visual awareness while responding concurrently to different components and aspects of retinal stimulation, and (2) how visual awareness is maintained in a meta-stable state so that it shifts from one coherent scene interpretation to another (driven spontaneously or by attention) at a rate optimized for efficient analyses of the visual environment.

Location:

In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/99656192503
Passcode: NICO2023

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.

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Speaker:

Yian Yin, Assistant Professor of Information Science, Cornell University

Title:

Understanding the punctuated dynamics of scientific and technological frontiers

Abstract:

TBA

Speaker Bio:

Yian Yin is an assistant professor of information science at Cornell University. His research applies and develops novel computational tools to understand how individual, social, and environmental processes independently and jointly promote (or inhibit) scientific progress and innovation achievements. As a computational social scientist, he has also used science and innovation as a powerful lens to examine broader processes and outcomes in a wide range of complex social processes, from artistic and cultural productions to public policy, from media attention to market competition to human conflict. Yian received his Ph.D. in Industrial Engineering and Management Science at Northwestern University, with research affiliations at Northwestern Institute on Complex Systems and Kellogg Center for Science of Science and Innovation.

Location:

In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/91574900792
Passcode: NICO2023

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.

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Speaker:

Joshua Jackson, Assistant Professor of Behavioral Science, The University of Chicago Booth School of Business

Title:

The History of our Minds: Evidence for Co-Evolution of Cultural and Psychological Processes

Abstract:

Biologically modern humans are more than 100,000 years old. Many scientists have devoted their lives to understanding how architecture, social structure, and language has changed over this history. Yet we know much less about the history of human minds. Behavioral science research has instead focused nearly exclusively on contemporary people, and psychological theories often draw from taxonomies which assume a culturally and historically stable structure to emotion, personality, morality, and other psychological processes. In this talk, I discuss new methods of studying the “psychological fossil record,” with emerging insights that challenge existing psychological taxonomies. Psychological change is often patterned and predictable based on cultural change, and general evolutionary principles may explain psychological changes in multiple domains. We now have the methodological and theoretical tools to build a more historically enriched science of human cognition and behavior, with a basic capacity to make foundational discoveries and an applied capacity to predict human futures.

Speaker Bio:

Joshua Conrad Jackson is an assistant professor of behavioral science at University of Chicago’s Booth School of Business. He studies how culture has shaped the mind throughout human history, and how it continues to shape human futures. He has published over 50 papers examining how historical and contemporary changes in technology, conflict, and migration have influenced moral psychology, emotion, prejudices, and belief systems. Prior to joining Booth, Josh was a DRRC Postdoctoral Fellow at the Kellogg School of Management. He earned his PhD from University of North Carolina at Chapel Hill and his BA from McGill University.

Location:

In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/99952026190
Passcode: NICO2023

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.

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Speaker:

Malcolm MacIver, Professor of Mechanical and Biomedical Engineering, McCormick School of Engineering, Northwestern University

Title:

TBA

Abstract:

TBA

Speaker Bio:

Malcolm A. MacIver is a group leader of the Center for Robotics and Biosystems at Northwestern University, where he is Professor with joint appointments between Mechanical Engineering and Biomedical Engineering, and an additional appointment in the Department of Neurobiology (courtesy). His work focuses on extracting principles underlying animal behavior, focusing on interactions between biomechanics, neuronal processing, evolution and sensory system properties. He then incorporates these principles into advanced biorobotic systems, or large scale simulations on computing clusters, for synergy between technological and scientific advances. For this work he received the 2009 Presidential Early Career Award for Science and Engineering from President Obama at the White House. MacIver has also developed interactive science-inspired art installations that have exhibited internationally, and frequently consults for science fiction film and TV series makers.

Location:

In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/97462977152
Passcode: NICO2023

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.

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Speaker:

Vicky Chuqiao Yang, Assistant Professor in System Dynamics, Sloan School of Management, MIT

Title:

Dynamical system models for voting and collective decisions

Abstract:

I will overview two studies using behavioral dynamical system models to study voting and collective decision-making. The first proposes a mechanism for the polarization of the US Congress despite the lack of clear evidence for voters taking more extremist policy positions. The model considers voters using the bounded-rational, satisficing decision-making---one chooses a candidate who is good enough instead of finding the best option. The model suggests that party polarization can be an outcome of increasing ideological purity within the parties without changes in the voters' policy positions. We also compare models' predictions with historical data. The second project further examines the potential disconnect between voter's preferences and the winning outcomes. It is well known that many voters in the US do not evaluate the merit of the options themselves (individual learning), but follow others (social learning). I use a dynamical model to investigate whether a majority vote system can settle on the better of two options under the presence of social learners. The model predicts a critical proportion of social learners above which either option can win the majority regardless of merit.

Speaker Bio:

Vicky Chuqiao Yang is an Assistant Professor of System Dynamics at the MIT Sloan School of Management. Her work uses quantitative behavioral models, assisted by the analysis of data, to study collective human behavior on a broad range of organization levels, from teams to cities. Recent research applications include collective decision-making, political polarization, scaling laws in cities, and bureaucracy in organizations. She received her PhD in Applied Mathematics from Northwestern University and was a fellow at the Santa Fe Institute.

Location:

In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/95731218751
Passcode: NICO2023

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.

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Speaker:

Tessa Charlesworth, Assistant Professor in Management & Organizations, Kellogg School of Management, Northwestern University

Title:

Mapping long-term change in attitudes and stereotypes

Abstract:

How do the humans of today think and feel differently than the humans of the past? In particular, when it comes to our attitudes and stereotypes of social groups, defined by gender, race, sexual orientation, and more, where has our society progressed, regressed, or remained stagnant? In this talk, I will lay out the evidence of change versus stability using empirical records from archival surveys of humans’ attitudes and stereotypes (part one) as well as expanded records of attitudes and stereotypes that can be gleaned from traces of naturalistic language (part two). I will close by discussing a new framework for how we conceptualize these records of change across multiple levels of analysis, sources of change, and durability of change.

Speaker Bio:

Tessa Charlesworth is an Assistant Professor in Management & Organizations at the Kellogg School of Management at Northwestern University. Her research tackles the question of how and why biased thoughts (beliefs) and feelings (attitudes) of social groups change across the long timespans of history, as well as across more immediate interventions. She uses a multi-level, multi-method approach: seeking to understand change within the micro-level of an individual, within meso-level aggregates (e.g., demographic groups, organizations), and at largest macro-level of our entire society. To do so requires methodological insights from across social, developmental, cognitive, and quantitative psychology, as well as computer science, organizational behavior, sociology, and economics, including laboratory experiments, natural language processing, time series, and big data analyses. Professor Charlesworth received her PhD from Harvard University.

Location:

In person: Kellogg Global Hub room L130 (lower level) - please note, this is a different location than usual.
Remote option: https://northwestern.zoom.us/j/95822930327
Passcode: NICO2023

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.

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