“Why did I eat that?” The answer lies in a feast of thought-provoking research with a lineage in PBS.
On March 2, University of Michigan Professor of Pharmacology Carrie Ferrario delivered the 2026 Eliot S. Hearst Memorial Lecture, “Why did I eat that? Neurobiology of cue-triggered food cravings in an obesogenic world.” The lecture was part of the annual Hearst Memorial Lectureship that brings leading thinkers in psychological and brain sciences to campus, thanks to the vision of its donors Joe Newman and Alida Evans who sought to honor their former PBS mentor.
Ferrario’s studies of obesity-prone and obesity-resistant rats are making major contributions to understanding the food-related behavior that leads to obesity. Among the issues she addresses are whether reward systems in the brains of obesity-prone rats respond differently to environmental food cues and whether those differences are further exacerbated by both weight gain and a diet of sugary, fatty foods.
As it happens Ferrario is an IU and PBS undergraduate alumna, who graduated in 2001 with a B.A. in psychology and English. And in her introduction to Ferrario’s lecture, PBS Professor Cara Wellman suggested that “you can see a throughline” in what “might seem like a sort of circuitous research path: from her honors thesis at PBS to her graduate work on addiction to her current work.”
We are not long into Ferrario’s own discussion, when she too begins to highlight that throughline. “I am so honored to be asked to speak today,” she explains, “not just at my alma mater, but also in this Hearst Lecture. Dr. Hearst did a lot of work in the fields of Pavlovian learning, and some of the concepts that he pioneered are really central to what I’m talking about today.” Many of those concepts, she observes, were also central to “what I learned first in Joe Steinmetz’s lab in the context of eyeblink conditioning, which I still find fascinating and incredibly useful.” And similar fundamental principles of learning underlie much of her current research.
Ferrario’s arrival in PBS Professor Emeritus Joe Steinmetz’s lab over 25 years ago was the result of an NIH grant that supported undergraduates from underrepresented groups who were interested in science and medicine. She is clear to point out, “I did not come to the university knowing what I wanted to do. I had no idea what I wanted to do.” Yet, early in her undergraduate career, a graduate student in our department recognized her talent and suggested that she get involved with research. He also told her about the program, and she applied. “It was that funding to do research,” she explains, “that really made my pursuit of this field possible at the time.”
Since then, her research has taken off. She received her Ph.D. in neuroscience from the University of Michigan where she studied the neurobehavioral basis of addiction and conducted postdoctoral research that led to her current research in the neural mechanisms contributing to food cravings and obesity, for which she has won numerous awards. As PBS Professor Dale Sengelaub puts it, “She just lit the world on fire and kept going.”
She is now, as Wellman suggests, taking the study of obesity in new directions by identifying changes in the brain’s reward circuitry that are distinct to obesity-prone rats. As Ferrario noted, “Most of the research had focused on metabolism and the regulation of energy balance, homeostasis, hunger, satiety, and energy storage. And, of course, those things are very important. But there really wasn’t much at all on these motivational circuits and how they function in an obese state.”
She and her collaborators have since found “that these Pavlovian food cues more strongly influence food-seeking behaviors in obesity-prone rats before they ever become obese,” she explains, and they further seek to illuminate “the neurobiological basis of that, how those behaviors are shifted by both weight gain itself and a diet of sugary, fatty foods.” As they observe, something shifts in the biology, “particularly in the function of the nucleus accumbens that’s important for these types of cue-triggered urges to seek out food.”
Ferrario spent the day in conversations with faculty, undergraduates, and graduate students. In a coffee hour with undergraduates, she answered questions about how obesity compares to various types of addiction and substance use disorders, as well as to eating disorders like anorexia and bulimia. Ferrario distinguishes it from those conditions, though fully explaining the differences is still “the million-dollar question.” She discussed the place food has more broadly in our lives, whether for sustenance, social connection, comfort, and celebration. She discussed how cultural norms with respect to body weight collide with the recent emergence of GLP1 drugs.
She also raised the issue on which she concluded her lecture, that while obesity is the result of an unhealthy food environment, it cannot be said to be the result of maladaptive behavior. Instead, the mechanisms and behaviors she studies developed on a much larger evolutionary timescale and have been evolutionarily adaptive. “I think it’s a really important thing for us to think about as we do these types of studies in the field, generally speaking,”
she suggested.
It was altogether an enlightening and provocative feast of ideas – everything the Hearst Memorial Lectureship is meant to be. As Sue Muthukarunakaran, a senior majoring in neuroscience, reflected, “I could have listened to her all day.”
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