Dr. Liberty Hamilton
Assistant Professor University of Texas at Austin
Postdoctoral Researcher University of California, San Francisco
PhD in Neuroscience University of California, Berkeley
Written by Sydney Smith
On our journeys into the wonderful realm of neuroscience, we often think that the most important part is our accomplishments: our acceptances, awards, and publications. However, we must never overlook the positive impact of the people we meet along the way. In addition to her impressive academic successes, Dr. Liberty Hamilton has traveled her path in neuroscience alongside a community of excellent mentors, supportive lab mates, and inspiring research participants. Now, as an Assistant Professor at the University of Texas at Austin, Liberty studies the neural basis of speech and auditory perception and production in humans.
Liberty’s path into neuroscience was circuitous. Growing up in the outdoorsy Colorado town of Boulder, Liberty first aspired to a career in geophysics, inspired by her geophysicist neighbor. After working a summer job for her neighbor’s company in high school, Liberty discovered how much she loved science, and was excited by the adventurous life a geophysicist could lead. With dreams of traveling to the most remote regions of the world and climbing volcanoes, Liberty started her undergraduate degree at Scripps College, a small liberal arts school in Claremont, California. However, upon taking her first geology class, she found that she didn't actually enjoy it. Realizing that geology may not be for her, she instead began to search for a way to combine her scientific curiosity with two of her other interests: language and music. Liberty took a class on introductory neuroscience and was fascinated. With the encouragement of her very supportive piano professor, Dr. Hao Huang, she decided to switch her major to neuroscience, specifically because its interdisciplinary nature allowed her to think about how music and language were represented in the brain.
Even though graduate school wasn’t initially on her radar after graduating, Liberty sought a research assistant position that would allow her to continue doing the neuroscience she loved. After cold-emailing faculty across southern California, she found a job working at the UCLA Laboratory of NeuroImaging (now the UCLA Brain Mapping Center) with Dr. Katherine Narr. In a building Liberty describes as akin to “working in a spaceship,” the Narr lab was using structural and functional MRI to study patients with schizophrenia and bipolar disorder. The lab was small, and Dr. Narr was very supportive, treating Liberty as an unofficial grad student. After spending two years experiencing what doing real neuroscience research was like, she decided to pursue grad school.
In her applications to PhD programs, Liberty searched for a university where she could pursue her interests in auditory neuroscience. She also wanted to find a program where her partner, Alex Huth, who was also applying to PhD programs, would be accepted. After applying together, Liberty and Alex chose the Helen Wills Neuroscience Institute, UC Berkeley’s PhD program. Liberty reflects upon her experience very fondly, “I can’t say enough good things about my time at Berkeley.” She chose to join the lab of Dr. Shaowen Bao, who studies auditory perception in rodent models. In her PhD work, Liberty implemented the then emerging technique of optogenetics to manipulate the activity of inhibitory cells in the auditory cortex of rats. Although learning a new technique was challenging, Liberty was overwhelmed by the generosity and support shown to her by Dr. Bao, her impressive lab mates, and the neuroscience community at the Helen Wills Institute. Despite her research success, Liberty felt exhausted and burnt out after five years of PhD research, and she often pondered alternative career paths with a group of trusted friends. After exploring her options in industry via informational interviews in data science, she concluded “that I did really like research, I just needed a little break.” As a way to reset after finishing her PhD, she spent a month traveling in New Zealand with her partner.
Following her decision to stay in research, Liberty started a postdoc, staying in California to work with Dr. Eddie Chang, a neurosurgeon at UC San Francisco. In Dr. Chang’s lab, Liberty found an exciting opportunity to work with human intracranial recordings: an invasive type of brain activity recording in patients who receive brain surgery. Although patients with epilepsy are most commonly treated with medication, a patient with severe epilepsy might not respond to any pharmacological intervention. For these patients, their condition may severely hinder their ability to lead a normal life: preventing them from doing things like driving or earning a living. The persistence of their seizures, and the effect they have on their quality of life, may lead these patients and their doctors to consider surgical interventions. In these surgeries, neurosurgeons aim to remove diseased brain tissue where seizures originate to prevent them from spreading to the rest of the brain. To find that tissue, surgeons and epileptologists implant electrodes on the surface of the brain and insert probes of electrodes into deeper brain structures, allowing them to record brain activity from very precise locations. Once implanted, patients will stay in the hospital under close observation for about a week. From there, an epileptologist will identify the location of the seizure origin and the neurosurgeon will remove it. These surgeries present a rare and exciting opportunity to record data directly from human brains, which is otherwise impossible due to the serious ethical limitations of performing such an invasive procedure on healthy subjects. Patients undergoing this surgery will often discuss this research opportunity with their doctors and generously agree to participate in short research experiments. Scientists can perform these experiments both in the operation room itself and during the monitoring period, as the implanted patient waits in the hospital. This is the kind of research Liberty did during her postdoc.
In her research with Dr. Chang, Liberty wanted to understand the pathways underlying speech perception. Up to this point, neuroscientists believed that when we listen to speech sounds, those sounds follow a single pathway from the ear, to primary auditory cortex, to association areas that begin to process those sounds as speech. However, Liberty found that stimulating primary auditory cortex while a patient listened to speech sounds, which should have interrupted their perception of the speech, had no effect on their ability to understand what word was played. This surprising finding has opened new areas of research to investigate what other pathways could exist in the auditory system that contribute to speech perception. Now, Liberty is investigating some of these questions in her own lab.
Now an Assistant Professor and principal investigator at UT Austin, Liberty continues to use intracranial recordings in humans to study auditory perception and speech cognition. In the first few years after starting her lab, Liberty collaborated with neurosurgeons and other clinicians at UT Austin in Austin, TX, and Baylor College of Medicine in Houston, TX to set up the complex research conditions for intracranial recording. Her lab works with children and teens to understand how auditory pathways and speech perception develop through adolescence using naturalistic sounds as stimuli in her tasks. She also runs similar experiments in healthy subjects using non-invasive scalp EEG. At every step of her career, Liberty has found inspiration in the people she has met through her research, from the resilient patients who inspire her science, to the vibrant friends, impactful mentors, and supportive research colleagues who have lifted her up throughout her career. Liberty’s passion for her work and the brilliant vitality she draws from her community and friends have propelled her into a promising career as a successful neuroscientist.
Find out more about Liberty and her lab’s research here.
Listen to Meenakshi’s full interview with Liberty on February 7th, 2023 below!
