The human brain isn’t a single instrument, or even one system. It’s a vast array of processes, all running at the same time, sometimes even in competition.
“People are really a complicated machinery of many systems running in parallel, and we assume that they are a unified entity because in most people, there are mechanisms to keep all of these separate programs running in a coherent fashion,” said neuroscientist and psychiatrist Michael Halassa. “When that coordination breaks down, people can lose contact with reality. It’s hard to understand how fragile these mechanisms are until we see somebody experiencing psychosis.”
Halassa believes psychiatry must adjust to recognize these connections.
He has spent two decades tracing these mechanisms to their source. His research program, grounded in algorithmic circuit psychiatry, treats psychotic symptoms as failures of specific neural algorithms — particularly those the brain uses to interpret an uncertain world.
“We need a new framework for psychiatry and there is a great opportunity to contribute to that here in Roanoke, building on the strong programs in computational psychiatry at the FBRI and the excellent clinical care at Carilion Clinic psychiatry,” he said. “This new framework should bridge the gap between brain circuits and the algorithms they implement, connecting both to meaningful clinical intervention.”
Bringing brain science into the clinic
A professor with the Fralin Biomedical Research Institute, Halassa is exploring these intricate connections in the brain at the new Virginia Tech Patient Research Center at VTC, where he will conduct patient-based research in a clinical setting.
“There has never been a good biological understanding of psychosis, and Dr. Halassa brings a whole new approach based in leading edge experimental and computational science,” said Michael Friedlander, executive director of the Fralin Biomedical Research Institute at VTC and Virginia Tech’s executive vice president for health sciences and technology. “Psychiatry is one of the most challenging areas in medicine because of the complexity of the disease — with contributing factors including genes, environment and lifestyle. We’re excited to have a leading-edge physician-scientist using laboratory-based experimental approaches, computation, and clinical research with patients who need of new insights and treatments.”
Friedlander said Halassa’s program will amplify the research institute’s established national leadership role in computational psychiatry, led by Read Montague, Pearl Chiu, Brooks Casas, Stephen LaConte and Alex DiFeliceantonio.
Halassa’s laboratory work has focused on the thalamus, a region long regarded as a relay of signals to the brain’s outer layer, the cerebral cortex.
His research was the first to demonstrate that the thalamus plays an active role in shaping cognitive processing within the brain’s frontal network. That work has resulted in foundational studies including several primary papers published in Nature[MH1] helping establish the thalamus as a central node in cognitive control and a plausible target in disorders like schizophrenia. He also is the sole editor of The Thalamus by Cambridge University Press.
The thalamus extracts various signals from the frontal cortex, identifying what task should be solved and how reliable various task-relevant signals are. These findings explain why recent evidence points to the thalamus as a critical node in psychotic disorders and a target for deep brain stimulation in these conditions, he said.
“It works like a forecasting system,” Halassa said.
From many systems, one mind
“When I was in medical school, I developed an interest in the brain,” he said. “And at the time I also became philosophically interested in the question of, ‘What does it mean to have a mind?’ I got interested in the problem of consciousness. Like, what does it mean to be me? And how does science kind of begin to ask questions like that?”
After medical school, Halassa obtained his doctoral degree in neuroscience at the University of Pennsylvania, followed by a postdoctoral fellowship at Massachusetts Institute of Technology with Matthew Wilson, while pursuing his psychiatry residency at Massachusetts General Hospital.
In 2020, after focusing for seven years on basic circuit and systems neuroscience, Halassa returned to part-time clinical work. After so many years of thinking about thinking, his view of psychiatric disorders had dramatically shifted.
He was struck by the epiphany that the brain isn’t one system, but many.
“There is no homunculus, no little man in the brain directing everything,” said Halassa, “The brain is a collection of systems that require constant coordination. You take away some of that coordination and it starts to look like people are actually multiple separate entities with little coherence among them.”
Matching patients to the right treatment
Halassa’s clinical research focuses on precision psychiatry, identifying features that would allow psychiatrists to match patients to the right treatment. In 2025, he published a paper in Nature Mental Health on clinical features that predict response to Xanomeline/Trospium (XT) a first-in-class medication for adults with schizophrenia. He identified negative symptoms, characterized by poverty of thought and action initiation, to be particularly sensitive to this medication.
“In my lab, we now have a fully integrated basic science to translational science to clinical program aimed at understanding and treating negative symptoms,” said Halassa. “We have developed tasks in patients that appear to track negative symptoms that can be back-translated into laboratory animals. We could not be more excited about this.”
Now, as the first faculty member to join Virginia Tech’s new Patient Research Center at VTC, Halassa will build a patient-based research program in neuroscience alongside his laboratory program, with clinical research in partnership with Carilion Clinic.
Halassa joined the Fralin Biomedical Research Institute as a professor with an appointment in psychiatry and behavioral medicine at the Virginia Tech Carilion School of Medicine and in the Department of Biomedical Engineering at the Virginia Tech College of Engineering.
“Dr. Halassa represents the kind of physician-scientist leadership that defines the future of academic medicine in general and academic psychiatry in particular,” said Robert Trestman, chair of psychiatry and behavioral medicine at the Virginia Tech Carilion School of Medicine and Carilion Clinic and institutional research officer at Carilion Clinic. “Integrating research with patient care is essential to advancing medicine by accelerating discovery, improving outcomes, and ensuring that our patients benefit from the latest scientific insights. Our collaboration with Fralin Biomedical Research Institute at VTC enables us to translate discovery into practice, and Dr. Halassa’s arrival strengthens our shared mission.”
Halassa came to Virginia Tech from Tufts University and was previously a faculty member at MIT and New York University. He brings with him a research group of 10 other members, including two research assistant professors, four postdoctoral fellows, an M.D./Ph.D. student, and three research assistants.
He is a winner of the Vilcek Prize for Creative Promise in the Biomedical Sciences given to immigrant scientists who made “lasting contributions to American society.” He has also received several other national and international awards and recognition from the Pew, Klingenstein, Feldstein, Simons, Sloan, Kavli, Max Planck and Brain and Behavior Foundations, among others.
“At this point in my career, I want to build a coherent research program that will move our understanding of reasoning and its breakdown in psychotic disorders forward,” said Halassa, who writes extensively about neuroscience and psychiatry on Substack. “This will require more precise measurements, and modeling of the underlying neural processes at different scales. I think we have a real opportunity to do that here. This is the right place and we’re here at the right time.”