SSP Forum: Julia Fischer, JD Pruett, and Xi Jia Zhou (M.S. Candidates)

The
Symbolic Systems Forum(
community sessions of SYMSYS 280 - Symbolic Systems Research Seminar)
presents

Evaluation and Comparison of Statistical Models for Intensive Longitudinal Data
Julia Fischer(M.S. Candidate)
Symbolic Systems Program

Ontologies of Cognitive Control: Evidence from Self-Regulatory Interventions in Binge Eating and Smoking
JD Pruett(M.S. Candidate)
Symbolic Systems Program

Simulating variation in infant-caregiver attachment using reinforcement learning
Xi Jia Zhou(M.S. Candidate)
Symbolic Systems Program

Monday, May 5, 2025
12:30-1:45 pm PT [Note - extended ending time]
Margaret Jacks Hall (Bldg. 460), Room 126
In-person event, not recorded
(see below for entry instructions if you are not an active Stanford affiliate)

Note: Lunch is provided, if pre-ordered, only for members of SYMSYS 280, but others are welcome to bring a lunch and eat during the presentation.

Abstracts:

Julia Rose Fischer, Evaluation and Comparison of Statistical Models for Intensive Longitudinal Data (Primary Advisor: Nilam Ram (Psychology and Communication)
     The advent of intensive longitudinal data gives rise to complex nonlinear models of psychological processes. Though theory can help guide model selection, it is still unclear how to choose models that are appropriately complex and accurate for examining the phenomenon of interest. My thesis develops a framework for selecting statistical models for intensive longitudinal data in a principled manner. Drawing on literature from both social science and machine learning, I argue that neither qualitative model assessment nor automated accuracy testing is sufficient for selecting an appropriate longitudinal model. I instead offer a structured model selection framework that integrates three model properties — complexity, efficacy, and interpretability — to provide clarity on which models are best aligned with a researcher’s analysis goals. To illustrate the practical utility of the framework, I apply it to an example research inquiry focusing on the time-oriented process of cognitive skill acquisition.

JD Pruett, Ontologies of Cognitive Control: Evidence from Self-Regulatory Interventions in Binge Eating and Smoking (Primary Advisor: Russ Poldrack, Psychology)
     Self-control is central to daily functioning, yet failures of self-regulation remain a major driver of health-risk behaviors. Why do some individuals improve with support while others continue to struggle? This study investigates the neural mechanisms underlying behavior change in two populations for whom self-regulation is critical: people who smoke and those with binge eating disorder. Using a pre/post fMRI design paired with a month-long intervention, we examine how brain activity during tasks involving impulse control, delayed reward, and craving regulation shifts with daily self-regulation training. Our goal is to identify which cognitive processes are most responsive to intervention and how those changes relate to real-world behavior. This work is part of a broader effort to build a structured framework—or ontology—of self-regulation that can guide more targeted and effective interventions.

Xi Jia Zhou, Simulating variation in infant-caregiver attachment using reinforcement learning (Primary Advisor: Nick Haber, Education; Second Reader: Mike Frank, Psychology)
     Infants’ attachment to their caregivers is a central feature of their early social and emotional development. Attachment Theory posits that these relationships vary systematically across distinct styles, though there has been debate about the extent to which these differences reflect features of caregivers’ responsiveness vs. infants’ own temperament. We develop a simple reinforcement learning model of infant exploration that allows us to vary the characteristics of simulated infants and caregivers and analyze the resulting patterns of model behavior. A set of equilibria reliably emerges that corresponds qualitatively to canonical attachment styles; particular agents’ equilibria are controlled by both caregiver and infant parameters. These simulations point the way towards a quantitative synthesis of prior theoretical debates about the nature of attachment.

Notes on entry to the meeting room:

Entry to the building is open to anyone with an active Stanford ID via the card readers next to each door. If you do not have a Stanford ID, you can gain entry between 12:15 and 12:30pm ONLY by knocking on the exterior windows of room 126. These windows are to the left of the west side exterior door on the first floor of Margaret Jacks Hall, which faces the back east side of Building 420. Please do not knock on these windows after 12:30pm when the talk has started. We will not be able to come out and open the door for you at that point.