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Interview with Dr. Aimee Nelson

Journalist: Yumnah Jafri

Yumnah Jafri: Welcome to SciSection. My name is Yumnah Jafri, and I am the journalist for the SciSection radio show, broadcasted on CFMU 93.3 FM radio station. We are here today with Dr. Nelson. Thank you so much for taking the time to meet with me today.

Dr. Nelson: You're welcome. My pleasure.

Yumnah Jafri: For our listeners who may not know the amazing work you're doing; I'll give you a chance to introduce yourself.

Dr. Nelson: Thanks, Yumnah. I'm a professor in the Department of Kinesiology here at McMaster University, and I'm also a Canada Research Chair, Tier 2 in Sensorimotor Neuroscience. I did my undergraduate degree here at McMaster in the Faculty of Science, and this was followed by my doctoral studies at the University of Toronto. Afterwards, I did a post-doctoral fellowship at the Massachusetts Institute of Technology in the McGovern Institute for Brain Research, and I subsequently did a second postdoc position at the Toronto Western Hospital in the Division of Neurology and Movement Disorders.

Yumnah Jafri: Thank you so much for that background. I see that you've definitely had a lot of research on the neural system and brain. What made you interested in conducting this research in the first place?

Dr. Nelson: I became interested in studying neuroplasticity during my post-doctoral position at the Toronto Western Hospital. It was there that I was working on a research study involving patients with focal hand dystonia. These individuals have unwanted muscle contractions typically during tasks that are highly repetitive and practiced, and these contractions can lead to difficulties performing regular tasks. Often, they alter the career trajectory of these individuals. For example, several participants in our study have musicians’ dystonia, whereby unwanted movements in the hands were observed during playing a musical instrument. I had the interesting opportunity to perform some brain mapping using functional magnetic resonance imaging in patients with focal hand dystonia. While the participants were lying within the magnetic resonance scanner, I stimulated their fingers using a vibration device. What does this typically look like in the brain? While in a control participant, the fingers are represented in an orderly fashion from the thumb to the fifth digit.

But that was not the case in the patients with focal hand dystonia. It was very interesting because we noticed that the representation of finger digits were highly overlapping and sometimes disorganized or even reversed. So, this was evidence that neuroplasticity had taken place in an unwanted direction, and we call this maladaptive plasticity.

It inspired me to want to seek out new opportunities to change the adult human brain to induce neuroplasticity. Specifically, I like using non-invasive approaches to study neuroplasticity.

Yumnah Jafri: Thank you so much for that answer. I know most people typically think of plasticity in a positive sense of increasing your ability to adapt to your environment, but many people don't really take into account the maladaptive adaptations of the plasticity. What is the purpose of currently conducting research to induce plasticity in your models?

Dr. Nelson:

The overall purpose of my research is to understand how neuroplasticity is induced in humans and to create non-invasive approaches to induce neuroplasticity, to benefit humans.

In my lab, we use something called transcranial magnetic stimulation, which is brain stimulation, non-invasive, and it can induce neuroplasticity. This approach involves delivering an electrical current through a coil, and the coil is shaped sort of like a figure eight, and it induces a magnetic field that enters the brain and stimulates the neural tissue in the vicinity close to the location of this coil. We use this approach to create short-term changes in the neural activity within the motor cortex, which is the area of your brain that participates in the control of your movement. Most recently, we showed that this approach could reduce symptoms of pain in an individual suffering from pain caused by spinal cord injury.

We also use other non-invasive approaches to induce neuroplasticity, and one such approach involves using muscle activity called electromyography, as biofeedback to improve motor control in certain patient populations.

In this example, we have different patients wearing electrodes on the arms and the legs, and they use their muscle contractions to control a video game interface. They try to move objects on the screen in front of them using different combinations and patterns of their muscles. What we're doing is we're teaching the brain new patterns of movement that have been lost or new skills entirely for the individual.

A third approach that we're using to induce neuroplasticity involves both brain and muscle activity recorded simultaneously. In this case, we use the EMG from the muscle, and we use something called electroencephalography from the brain. What we do is we calculate the activity between them, the brain signal, and the muscle signal. This measure is called cortical muscular coherence. We use this cortical muscular coherence as a source of feedback to participants to improve their performance in motor tasks. For example, we have one study that investigates individuals with chronic neck pain, and the participant is required to rotate their head to a particular target location while brain signals and muscle signals from the neck are being record. The cortical muscular coherence is calculated for each trial and displayed to the participant, allowing them the opportunity to improve their cortical muscular coherence score in the next trial. So, it’s a feedback.

Last, my lab uses physical exercise like high intensity aerobic exercise as a means to induce neuroplasticity. This seems to be a great option in patient populations capable of meeting the challenging demands of exercise. We also see that exercise is a potent modulator of brain activity.

Yumnah Jafri: Thank you so much for letting us know about all these incredible techniques you're using in your lab, which I believe goes by the Neuro Lab at McMaster?

Dr. Nelson: That's correct.

Yumnah Jafri: It's incredible how many different integrated approaches you have to strengthen muscles, strengthen muscle memory, or induce new associations between the muscle and the mind. Thank you so much for letting me know about that. What are some key takeaways from what you have learned from your experiments at your Neuro Lab at McMaster?

Dr. Nelson: Thanks for that question. I think that the takeaways are applicable to everyone doing research in neurosciences, particularly in non-invasive brain stimulation. I really feel that research today should be interdisciplinary, involving expertise across a wide range of disciplines. And that's exactly what our lab does. So, any research project in our lab can include faculty from engineering, science and health sciences. We could even expand to humanities and social sciences.

The important point here is that having the perspectives and expertise across widespread disciplines allows the science to be very rich and detailed and impactful.

I think that's a key takeaway from the work we do. In terms of brain stimulation, a key takeaway is that any brain stimulation study should be equipped with a placebo or sham control. We've noticed, it's quite interesting how people respond to placebo stimulation, and nothing is being induced into the brain at that time by the coil. That's something we think about often.

Another piece relates to the reliability of measurements. We found in our brain stimulation approaches we always need to include a measure of reliability. This is because all our measurements, all our dependent measures can vary from one individual to another and they can vary from day to day, even within an individual. So, we need to incorporate statistical measures of reliability, so we can understand better how our measures are fluctuating. That's what I would say are the main big takeaways. They're sort of big picture takeaways, but I think they're important.

Yumnah Jafri: I completely agree with you. They're incredibly important, especially the fact about creating results or finding results in lab that you can actually apply to a variety of real-life situations and real-life groups of people. So, making it interdisciplinary rather than secluded to a specific field or a specific group of people. Is that correct?

Dr. Nelson: Absolutely. The students gain so much more from that experience because they are exposed to multiple supervisors, and they become leaders of a larger, more intensive project. The experience, overall, is quite different for trainees when they're required to do an interdisciplinary project. It's difficult at first to create an interdisciplinary team. It takes a long time, it takes trust, and you're developing professional relationships and friendships with people. It takes time. At the end, I think the results are worth the effort and time because we have a more thorough understanding of, for example, in our case, the mechanisms that underpan neuroplasticity.

Yumnah Jafri: So, the results are more meaningful. I completely agree with you and I'm so glad that you brought that up, especially. Going back a little bit further into your past, Dr. Nelson, what do you think you did differently compared to your peers (when you were an undergraduate student) that actually helped you become who you are today or develop the ideals about research and as you mentioned, interdisciplinary research that you have today.

Dr. Nelson: If I go back to my undergraduate studies, it's a long time ago. I don't think I knew anything of interdisciplinary studies at that time. I think that's emerged over the last, maybe six years of my faculty position. But when I was an undergraduate student, I did have a chance to work closely with a professor in neuroscience here at McMaster. Her name is Dr. Judy Shedden. I was very inspired by Judy. She introduced me to measurements of brain activity that we call EEG, I spoke about them earlier. I just loved working on my own research project and being a leader of a project, that was so exciting for me. It was really the first opportunity I had had in my undergrad degree to be able to have ownership over something that I cared so much about. Then I realized that Judy was—or I should call her Dr. Shedden at that time, I suppose. Now she's a colleague.

She was doing something she loved so much, and she was getting paid for this. It was sort of an eye opener for myself that I could actually do something I love, have a lifelong continuous journey of learning, and get paid for this. What could be better than that?

So, that's something that I really think I had a special opportunity and maybe some of my peers did not, and I think maybe some of my peers didn't because they didn't seek out those opportunities. It takes a bit of challenge, a bit of work, bit of courage for sure, to engage with professors. To have them open their door and have them give you a small chance. Judy did that for me many years ago, and to this day, I still use EEG and occasionally meet Judy on campus.

Yumnah Jafri: That is such an incredible story, that you're now working alongside the same mentor that you had when you were an undergraduate student.

Dr. Nelson: It's very exciting. It's really nice to see.

Yumnah Jafri: In terms of students who are listening to this show right now who may also be interested in pursuing research or a career in research, you mentioned going out of your way to get that opportunity, and persevering in terms of that initial research opportunity. But do you have any other advice that you could give our listeners today?

Dr. Nelson: I think getting in touch with a professor is sometimes a little difficult through email. The problem that we all face is that we're inundated with emails from people interested in pursuing research. There are so many highly qualified young people who want to be a part of your lab, and you only have space for a limited capacity. So, I would encourage undergraduates to actually seek out the professors in person to drop by their office and connect with them. I think that is a sort of bold, courageous approach that seems to work very well for students, at least in my lab. Where they've come to me, and they discuss what they want to pursue. Maybe they don't have a research idea, but maybe it's just a genuine interest and desire to learn. Once we've met you, it makes it so much easier to converse with you over email and again in person, and improves the opportunity for you to have a placement in the lab. So, I would really encourage to directly connect with professors in person if you can. It can be as simple as waiting until after class and talking to your professor and saying, I really enjoyed your lecture. I wanna know more about this. Is this the kind of work you do in your research lab? Then start like that or drop by their office.

Yumnah Jafri: In terms of what I've heard myself as an undergraduate student, I know many people still typically or rely on these cold email approaches to try and get a placement. But I think you're completely right, that it's important that you actually show your interest, by physically being there and talking to the professors. Or other labs or whatever you're interested in and being able to communicate with them like that. In terms of the scientific community as a whole, so instead of the undergraduate experience, what do you think the scientific community as a whole needs the most right now in terms of research or in terms of applying that research to populations? What are your thoughts?

Dr. Nelson:

Yes. I think that the most important drive right now is to take our basic science and translate it into applications for clinical populations,

and that's where my lab is headed. We started this initiative about four or five years ago. Of course, we were delayed by the pandemic when our lab was closed, but we are back on this mission. We want to develop things that people actually need and want to use. One of the new approaches we're using now is we're inviting patient populations into our lab early on in the development of research to find out and survey and garner what their interests really are. Then, we're using that information to guide the development of the research, so that the end product of what we are trying to achieve is something that can be applied directly to patient populations.

Yumnah Jafri: Thank you so much for that answer, Dr. Nelson. It's really important, I think, to take it from a step-by-step basis in knowing if the populations that you're trying to benefit, actually do benefit from what you're researching or what tools you're trying to create. That's a really important approach. For our final question, what do you think is the coolest or least well-known fact about neuroscience?

Dr. Nelson: Well, I think people don't realize how big neuroscience is in our world. The Society for Neuroscience is a society I belong to, and they have over 37,000 members worldwide. We host one of the largest conferences in the world. We're talking just days upon days and rows upon rows of posters, talks from trainees and professors, and it's very exciting. The field of neuroscience is enormous, ranging from molecular neuroscience all the way through to computational neuroscience. Behavioral and systems-level neuroscience! So many different aspects of neuroscience that people can engage in. The membership continues to grow. The areas and differentiation of these areas continue to flourish. So, I think it's really a exciting field of research to be in.

Yumnah Jafri: I completely agree. I think neuroscience is understated even though it encompasses such an important part of our system, the brain and everything to do with the brain. I hope our listeners today get at least a small taste of what it's like to conduct research within this field.

And that's it for this week of SciSection! Make sure you check out our podcast available on global platforms for our latest interviews.


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