During the past five years, Lee Miller, PhD, Edgar C. Stuntz Distinguished Professor of Neuroscience, professor in physiology and physical medicine and rehabilitation, has captured the world’s beauty and its curiosity all the same. An avid landscape photographer, Miller sits surrounded by scenes from Haiti, China, and Colorado, while maintaining a lab now globally recognized for re-animating the muscles of a paralyzed hand.
When the concept of a brain machine interface (BMI) was first published a decade ago, Miller began to anticipate the outgrowth of his basic science past. A physicist with a biomedical engineering master’s degree, McCormick ’84, he decided to pursue the basic science component of his studies further. After graduating with a PhD in physiology, FSM ’90, his post-doctoral research brought him to the Netherlands before returning to Feinberg as a research associate in 1992. Joining the faculty a year later, Miller continued with basic science research before shifting his grant application focus and migrating back to the biomedical engineering side of things about 10 years ago.
“My work with BMI started six or seven years ago,” Miller said. “My most recent research is really highly varied and multidisciplinary and illustrates how some components are only accomplished through collaboration with great science minds, while others depend on the technical knowledge of others. The past five years have been a difficult, very rewarding time in my career and my basic science past helped build an important critical foundation for the work I do today.”
What are your research interests?
The primary goal of the research we do is to understand the nature of the somatosensory and motor signals within the brain that control our arm movements. We study the language of these control signals and the networks of neurons that produce them. Our current lab focus centers around signals recorded from the brains of monkeys trained to reach for objects and do other hand movements. In addition to exploring the brain signals necessary to make those movements, we have begun looking at the somatosensory parts of the brain that supply our sense of touch and body position. Along with this basic research, we are working to develop neural interfaces that directly connect the brains of our monkeys with the outside world. These interfaces already allow human patients to operate a computer or a prosthetic device. A unique project in my lab is to bypass the injured spinal cord completely in order to reactivate paralyzed muscles through brain-controlled electrical stimulation. We are also working to restore the sense of touch and limb movement that is lost to spinal cord injury.
What is the ultimate goal of your research?
Most of the experiments in my laboratory involve recordings made directly from the brains of monkeys during behavior. In these experiments, we are able to study not only the intricate circuits comprising real networks of nerves and neurons, but also the signals produced by individual neurons during movement. Much of this work is done in collaboration with students and faculty from the biomedical engineering department and the neuroscience program.
The three fundamental goals of my research are to understand the nature of the brain’s own signals, to understand the mechanisms by which these signals are produced, and to develop applications of these basic principles that could be of therapeutic value to human patients.
The goal of our brain-computer interface research is to deliver messages from the brain directly to the muscles to enable voluntary and complex movement of a paralyzed hand. The muscles are activated through functional electrical stimulation (FES), a well-established clinical method that, uniquely in my lab, is controlled through signals from the brain. By bypassing the spinal cord, we see the opportunity to restore voluntary movement to humans with spinal cord injuries or amyotrophic lateral sclerosis.
Have you recently published any papers?
We recently had an article published in Nature, “Restoration of grasp following paralysis through brain-controlled stimulation of muscles.” We recorded the electrical brain and muscle signals using implanted electrodes while the monkeys grasped a ball, lifted it, and released it into a small tube. Those recordings allowed us to develop an algorithm or “decoder” that enabled us to process the brain signals and predict the patterns of muscle activity that occur when the monkeys grasp the ball.
Next we gave the monkeys a local anesthetic to block nerve activity at the elbow, causing temporary paralysis of the hand. With the help of the special devices in the brain and the arm, the monkeys’ brain signals were used to control tiny electric currents delivered to their muscles, causing them to contract, and allowing the monkeys to pick up the ball and complete the task nearly as well as they did before.
Who makes up your research team and what role does each individual play?
Christian Ethier, a post-doctoral fellow, was most critical to all aspects of the brain-FES project, and Emily Oby, a graduate student in neuroscience, assisted him closely, although the main focus of her work included basic studies of these motor control signals as well.
I currently have two technicians, Rebecca Friesen and David Bontrager, who assist in all of the projects in the lab, including the FES work.
Post-doc Nick Sachs and biomedical engineering graduate students Stephanie Naufel and Matt Perich are also working on projects to restore mobility through brain recordings and FES. Post-docs Brian London, Boubker Zaaimi, and Paul Wanda, along with neuroscience graduate student Ricardo Ruiz Torres and biomedical engineering graduate student Brian Dekleva are working on experiments to understand and restore somatosensation through cortical recording and stimulation as well as a project to study how sensory and motor signals are processed during reaching movements.
What do you enjoy about mentoring young scientists?
I really enjoy classroom teaching and mentorship. As my lab has gotten larger, it is a bit frustrating at times to not be in the lab much more. At the same time, I enjoy being at the center of our operations, organizing them, and making them happen. This has replaced much of the hands-on work I used to do. A major challenge in mentoring students is that in their entire student life they have been learning to answer questions – and getting quite good at it. Now is the time for them to start asking the important, solvable ones, which is the crux of what science is all about.