Kathleen E. Cullen received a PhD in 1991 from the Committee on Neurobiology. Her advisor was Robert A. McCrea. Dr. Cullen was a Fellow at the Montreal Neurological Institute where she worked in the Department of Neurology and Neurosurgy. In 1994, Dr. Cullen became an assistant professor in the Department of Physiology at McGill University, with appointments in Biomedical Engineering, Neuroscience, and Otolaryngology. In 2002, Cullen was appointed a William Dawson Chair in recognition of her work in Systems Neuroscience and Neural Engineering, and served as Director of McGill’s Aerospace Medical Research Unit comprising four faculty and their research labs. In 2016, Dr. Cullen moved to Johns Hopkins University, where she is now a Professor in Biomedical Engineering, and holds joint appointments in the Departments of Neuroscience and in Otolaryngology – Head and Neck Surgery.
Kathy's general area of interest is in systems and computational neuroscience, with an emphasis on translational approaches to restoring sensory function. Her research expertise lies in understanding the coding strategies that the brain uses to create neural representations of self-motion: she studies how the brain combines information from the vestibular sensors with extra-vestibular cues (visual, touch, motor) to estimate self-motion to ensure accurate motor control and postural stability.
One of Kathy's main findings has been the identification of a distinct and surprisingly small cluster of cells deep within the brain that reacts within milliseconds to readjust our movements when something unexpected happens. For instance, if a person starts to trip, the neck may flex to keep the head stable, the torso becomes more rigid so that the body remains upright and the legs and feet take a stutter step.
The experiment that lead to the discovery, devised by Kathy and one of her former PhD students, Jess Brooks, involved putting macaque monkeys inside a device similar to a flight-simulator. Monitoring their subjects' brain activity, the researchers were able to identify the specific cluster in the cerebellum that reacted to the unexpected movements they were creating. What is astounding is that each individual neuron in this tiny region (smaller than a pin's head) displays the ability to predict and selectively respond to unexpected motion.
This finding both overturned current theories about how we learn to maintain our balance as we move through the world, and also has significant implications for understanding the neural basis of motion sickness.
The study was published in the journal Current Biology, and was widely covered by the media, in the Wall Street Journal and PBS among other venues.
Want to learn more about Kathy's work? Check out her website and her Scholarpedia article.