Faculty Spotlight: Professor Wilsaan Joiner, PhD

As interviewed by Gabriela Lee

Wilsaan Joiner, PhD is a professor in the Department of Neurobiology, Physiology and Behavior in the College of Biological Sciences and the Department of Neurology at UC Davis Health. He is a member of the Steering Committee of the Center for Neuroengineering & Medicine and an affiliated faculty with the Center for Neuroscience, as well as the Principal Investigator of The Sensorimotor Integration Lab at UC Davis. Professor Joiner has been named a 2023 Chancellor’s Fellow earlier this year.

• Tell us about your background and current field of research.

My background is in biomedical engineering. I received my undergraduate degree from Saint Louis University in Missouri and my PhD from the Johns Hopkins University, School of Medicine.

I have a fairly broad training. My PhD work was focused on the control and modeling of eye movement behavior. And then I did a postdoc at Harvard with professor Maurice Smith, where I started my research in movement, looking at control and modeling of arm-reaching behavior, using robotic manipulandums. That experience was really influential and I still use the training I received in his lab.

My second postdoc was with Robert Wurtz at the National Eye Institute at NIH, recording from visuomotor areas of behaving non-human primates. While I had read a lot of papers in neurophysiology for graduate school, I only actually did neurophysiology experiments after arriving at the NIH and that was incredibly helpful. Both Maurice Smith and Robert Wurtz were great mentors and they supported me as I applied for and was awarded an NIH K99/R00 Path to Independence award to study visual perception deficits due to defects in information processing through the thalamus in patients with schizophrenia and psychosis.

All these experiences shaped the current research in my lab, where we study how we use sources of information to aid behavior, ranging from visual perception to movement planning and updating. The long-term goal is to apply what we learn to help patients such as those with schizophrenia, dementia, and upper extremity amputees.

At my previous institution - George Mason University - I continued my research in motor learning and control, as well as in visual perception. These seem like disparate areas but in reality, our body integrates internal (from our movements) and external information (visual along with auditory and proprioception) in order to make sense of the world and plan fine movements. While at George Mason University, I received a National Science Foundation CAREER award for a project titled “Probing the Neural Integration of Sensorimotor Signals for Limb Motor Coordination and Perception”.

George Mason University was a fantastic institution, I really enjoyed my time there. But what I couldn’t easily do was applying my research to patient populations. And that’s something I really had a strong passion for. One of the reasons I came to UC Davis is that I wanted to expand and study patient populations. Having a broader network of faculty members in different departments, different labs, with different interests, has helped expand our research program even more.

I collaborate with Jon Schofield in Mechanical and Aerospace Engineering to apply our motor learning and control findings to patient populations like children and adults who use prosthetics. This line of research has been really fruitful and we currently have several funded projects. Another collaboration we have is with Lee Miller in Neurobiology, Physiology and Behavior where we combine his EEG expertise with the robotic platforms in my lab to study neural signatures of learning and control. These are just two examples of exciting projects resulting from interactions with colleagues in other fields.

We are also expanding our research in a couple of other major directions. Together with Martin Wiener at George Mason University, we are exploring the question of how does this integration of information (visual and auditory, as well as from movement) affect perception, specifically time perception)? That is, how does movement interact with other incoming sensory information and how do they integrate to optimize human experience and behavior? A number of undergraduate and graduate students have worked on this project, and we have published a number of papers. In fact, one of my graduate students was selected for an NIH F31 award based on this work. In collaboration with Dr. Julie Schweitzer at the MIND Institute, we’ve also started to do some work with patients with ADHD to determine if the information provided by movement aids in cognitive tasks.

One of the benefits of coming to UC Davis was having a joint appointment in the Neurology department, which enabled more interactions with clinicians. We have a collaboration that’s just starting with the movement disorders clinic where we can look at motor learning and control in patient populations like Huntington’s and Parkinson’s disease to better understand what the deficits are in terms of modulating the control of their bodies.

It’s also been incredibly helpful to join UC Davis because we have the imaging research center led by Dr. Cam Carter, who is both a wonderful mentor and an expert in psychosis, schizophrenia, and bipolar disease. I’ve been able to pursue that aspect of my research program really well, including imaging of patients to understand the neural substrates of why there’s this difficulty integrating internally generated and externally induced information. This project expands and builds on the work I did at the NIH looking at non-human primates.

A lot of our work for our many projects is driven by my graduate students. They are very talented, and that allows our lab can pursue multiple lines of research. A graduate student leads each of the projects I listed above, making sure that we’re on task.

Joining UC Davis has been incredibly beneficial as it allowed me access to the research infrastructure and the faculty to enhance the things I was interested in. Along the way I’ve been fortunate to have access to strong mentors and collaborators—those listed above and others like Dr. Carolynn Patten. They have helped get things off the ground and provided advice, they assisted me in making the right choices, like what to think about when planning our research projects. It’s been a very supportive environment. Being at Davis afforded me a mix of strong mentors and incredible collaborators.

• How did you get to this research field? What led you to it?

When looking at college and what to major in, one of the things my father strongly suggested was the brain as the next frontier, to understand how the brain, memory, learning, how they all work. This is one really wide-open challenge in the sciences that we need to work on diligently. Furthermore, my father thought that engineering would be a good, solid major, and he was a strong influence on my pursuing biomedical engineering. As for graduate school, the chair of my department at Saint Louis University, Dr. Cecil Thomas, was highly influential in helping me decide my next steps. He connected me to Dr. Lawrence P. Schramm and I got to spend the summer of my junior year at the Johns Hopkins University, working in the lab of Dr. Reza Shadmehr, a well-known researcher in motor learning and control. That led to pursuing my doctoral degree at Hopkins and meeting Dr. Maurice Smith in whose lab I did my first postdoc.

In my experience, nothing happens in isolation. A number of people were incredibly helpful to my career. I continued to expand my network, and I had great mentors who connected me with others who then became mentors and later collaborators or colleagues.

• What’s your passion? What motivates you?

When it comes to research in general, one motivation is that I want to give back to the next generation of students through classes and lab experiences and help them be successful. All my former students from George Mason University and from UC Davis have been successful and have gone on to prestigious programs at universities like Carnegie Mellon, Harvard and Virginia Tech. A few are interviewing now for grad study at excellent schools like the University of Michigan, UC Irvine, and Caltech. They’ve done incredibly well. For both undergraduate and graduate students, I aim to help others just like my previous mentors helped me.

Another passion and motivation is that I really want my research to be impactful. It can be easy to fall into a trap of doing experiments for the sake of it or do research because it’s a popular area. A large reason for working with patients and having an affiliation with the medical school is to do research that is translational and that has the potential to be impactful. The work with schizophrenia is trying to get at the fundamental reasons of why do we experience psychosis? How do you effectively treat it?

For movement disorders, there’s a number of tools, paradigms and approaches that the motor learning and control community have developed and have thoroughly studied, but they are rarely used with patients because the implementation is difficult. For one, you need to have collaborations with clinicians, and that could be a challenge in itself. Second, getting access to patients is time consuming. There are some collaborations, but we need to do much more.

For the work we do with prosthetic users – patients vary from kids we see at Shriners Hospital to adults at UC Davis Health - the end goal is to develop better prosthetics and better interfaces for people to use. The appreciation and motivation that our subjects demonstrate means a lot to me. The kids get so engaged and they want so much to be part of what we are doing, that it motivates us even more. We really want to make an impact on people’s lives, and I think patients wouldn’t show that kind of enthusiasm and motivation if they didn’t feel that from us too.

In terms of motivation, I also think about my parents. They made significant sacrifices for their 4 kids to go to school and have opportunities. My oldest sibling has a degree in veterinary medicine. I have my PhD and so do my younger two sisters. We’ve all done quite well, and everybody’s been modestly successful. We wanted to take advantage of the opportunities that were given to us, and to make our parents proud — recognizing how much we received and trying to give others the same kind of opportunities.

• What would you like to see the field achieve in the next 5-10 years?

The work on prosthetics is probably the most tractable and where we expect to see the most tangible advancements in the next 5-to-10 years. I’d like to see interfaces that are intuitive. Even sophisticated devices that took a lot of resources and money for sensors and algorithms to try to figure out people’s intent, still face high rate of abandonment as people don’t find them particularly helpful. There are many talented and smart people working on this, so we expect to find solutions and develop devices that are useful, with minimal training necessary. This aligns with Sanjay Joshi’s vision of getting people who are affected by disease or injury back to a somewhat normal state but even beyond that, can you augment humans with extra limbs and exceed human capacity, to integrate machine and human users? In the next 5 to 10 years, I think people will make significant progress at thinking beyond traditional ways of obtaining signals or information for the interface between the user and the robotic system, and the work we are doing at UC Davis is going to be part of that progress.

For clinical populations, we’ll have to get a better handle on different disorders like Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease. The more we apply the information that we know about the motor system, how it learns, how it controls our limbs, the better we can diagnose and understand deficits and rehabilitate patients. We are at a point where we have the tools that we can leverage, and insights that should make things more tractable to study. It’s now a matter of putting in the effort and doing the systematic studies to really understand the diseases and injury states at a deeper level than we do right now. Like everything else, this will lead to more questions, more issues, and more complications. But I do think that we have the pieces to start really making a lot of progress in those areas.

If you have an engineering background, you are only limited by your imagination. If there’s something that you want to study, you can build the tools and develop the techniques necessary. Don’t be afraid of not knowing the answer, you can figure things out. For neuroengineering, when you have well-trained engineers who know how the nervous system operates, there’s a tremendous amount of opportunity to understand it at very fundamental levels, then be creative in terms of how you actually go about interfacing with it, manipulating it, modulating it. It’s an exciting time to be in this field of neuroengineering because there’s so much that’s available in so many directions that can be pursued. Advancements are going to come rapidly in the next 5 to 10 years. In addition, new insights, tools and technologies that are becoming available will further accelerate progress for addressing neurological disorders.

• What advice do you have for current & future students interested in neuroengineering? 

I would start with practical advice: if you are interested in pursuing neuroengineering, I recommend taking a lot of math classes – I wish I took more math when I was in college and during my PhD. The more math you know, the better. It will help you understand problems and modeling aspects. Second, don’t be afraid to fail. There will be plenty of times when things aren’t going to work out. There are tons of reasons to doubt yourself and get discouraged, when this paper got rejected, or that grant was not discussed, or someone really questioned your approach to proposed experiments. You must have some amount of trust in yourself if you believe in what you’re working on. You don’t want to give up as soon as trouble starts. Research is challenging and still it can also be very rewarding.

I would absolutely recommend finding a good mentor or rather a group of mentors, to help you become the best you can be – this is critical. You need people who will cheer for you, and you need people who will tell you when you’re wrong or give you hard advice. It can be difficult to hear, but it can help you to move forward, grow, and evolve from that.

And then, you definitely want to get experience in the lab. Undergraduate students ask for research experience and that’s great, but you need to know why you want to do it. What is your motivation for working in this field/lab? You want to be somewhat focused and devote enough time to a research project so that you can start to develop expertise and a certain feel for direction. This only comes with dedicated time, to better understand it and see if it’s a good fit.

Coming from less traditional paths into neuroengineering is fine. Just bring your strengths to projects, from whatever background you have. For example, for our work with prosthetic users, your field could be user design and human factors. It’s still useful to have a strong math background. What’s most important though is imagination.

One of the coolest things at George Mason University was working with the dance school. You can draw a parallel between dance and engineering. Developing choreography is almost like an algorithm – how the elements will align to give you an output. We had different vocabulary, but we were essentially doing the same thing. You need people who think outside the box or at least differently than you. When you come together, you can come up with unique solutions to the problem.

As mentioned earlier, science is not done in isolation. You need people that you can rely on and collaborate with, at UC Davis and other places. Also, you can’t do research without dedicated and talented graduate and undergraduate students. I’m grateful to Sanjay Joshi, Karen Moxon, and Carolynn Patten for their vision to develop a neuroengineering center at UC Davis. It helps us form collaborations, get access to talented students, build support for students and postdocs. We want to get more resources through an NIH T32 and other training grants as well as strengthen the infrastructure for writing joint proposals and conducting research to help patients with neurological disorders. We have many dreams and aspirations, as well as the infrastructure and talent to pursue them.