Editor's Note: Three young investigators were honored with awards at the International Association for the Study of Pain’s 16th World Congress on Pain in Yokohama, Japan, 26-30 September 2016. After the meeting, the award winners spoke by phone with Neil Andrews, PRF executive editor, to discuss their research. Below is an edited transcript of an interview with Tasha Stanton, winner of the Ronald Dubner Research Prize. Also see interviews with Luana Colloca and Marco Loggia.
Tasha Stanton is a National Health and Medical Research Council Early Career Fellow and Senior Research Fellow working with the Body in Mind research group at the University of South Australia, Adelaide, and Neuroscience Research Australia, Sydney. She received an MSc in rehabilitation science in 2007 from the University of Alberta, Canada, and a PhD in medicine (public health) in 2010 from the University of Sydney.
Why did you become a pain researcher?
I originally trained as a physiotherapist and started clinical practice at a worker’s compensation rehabilitation unit where we saw a variety of patients with different chronic conditions, such as back pain, burns, and itch. I saw so many very challenging and interesting cases where it wasn’t always clear how to choose the best treatment for the patient, given the knowledge available at the time. That experience really sparked a lot of questions for me.
At that point, I looked into doing a master's degree; I thought I’d try doing research and see if I liked it. So I went back to the University of Alberta, where I had completed my bachelor's, and started a master's degree with Professor Greg Kawchuk, who studied spinal biomechanics. I really loved it—it was a chance to be creative, to problem solve, and to ask the questions I wanted to ask. That experience opened the door to research for me. I was then fortunate enough to get an international recruitment scholarship to go to the University of Sydney to complete my PhD; this was with an excellent pain epidemiology group, including physiotherapists. My PhD investigated how to determine which treatments patients will best respond to, using subgrouping methodology.
During my PhD, I also read a lot about clinical pain neuroscience and was absolutely intrigued. So I took a leap of faith and decided to change my research focus after I completed my PhD. I was able to get a Canadian Institutes of Health Research postdoctoral fellowship and made the switch into pain neuroscience, which is what I've been studying for almost seven years now at the Body in Mind research group. It's fantastic—it’s such compelling work. I get really excited about the mechanisms behind things, and so to get to study exactly that is great. When I realized this, I knew I was a pain researcher and that I was exactly where I wanted to be.
What does your work focus on?
I'm interested in evaluating the role that our perception of our own body plays in pain. I became intrigued by the fact that in chronic pain conditions, people will often have altered perceptions of their body—it feels wrong to them, too big or too small, and their ability to localize touch on their skin, or know where their limb is in space, is poor. What we're starting to see is that these dysfunctions likely involve not only things happening in the periphery but also in the brain, too, and I've been quite intrigued with that relationship.
That led me into the field of multisensory integration, which looks at how the brain combines different sensory information about the body to give you a dynamic perception of who you are. It is this perception that helps you know where "you" end and where space begins, and it allows you to interact with the world. I’m now trying to understand what role multisensory integration might play in pain.
I chose this focus primarily out of curiosity but also because it's really nice to work with patients, explore some of the strange perceptions or feelings that they have, and then try your best to figure out why those are occurring. Giving people an explanation—even if it's based only on theory—is helpful because there's nothing scarier than not knowing why something is happening to you.
What are the major projects you are working on now?
I just completed a project—we’ve now submitted it for publication—looking at multisensory integration in people with chronic low back pain and stiffness. We were asking the question, When you feel stiff in your back, does that reflect that you are truly stiff—that is, are the joints themselves actually stiff and that's why you have the sensation of stiffness? The short answer is, "No!" Using an objective, validated way of measuring actual stiffness of the back, our work showed that feelings of back stiffness don't relate at all to these objective measures of back stiffness. Thus, our perception is not in line with what is going on in the periphery.
What we did find, though, is that how stiff your back feels relates well to protective behavior at the back. We assessed this protective behavior by having people estimate how much force they thought we applied to their spine; we used a specialized machine to apply force. People who feel very stiff in their back greatly overestimate how much force is being applied to their back—they think they are in more danger than they really are—while those who feel less stiff are much more accurate. And this is where it got fun! We then used a paradigm where we paired different sounds to the force applied to the back to see if we could modulate this perception of force that relates so well to feelings of stiffness. We did this by playing a creaky door noise: Every time force was applied to the back, subjects heard a big creak that was perfectly synchronized to the force pushing into their back. Right away, that made people become much more protective of their back; they started to overestimate the force being applied, even more so than before. This suggests that our bodily feelings are created using various sources of sensory information—it’s a really complex process—and that we can manipulate perception based on altering this sensory information.
Similarly, I’m just about to submit another paper that evaluated the effect of multisensory illusions in people with painful knee osteoarthritis. We use a set-up of cameras and video goggles to alter video in real time—so people see their own knee and watch it grow/shrink and change in front of their eyes. We incorporate principles of multisensory integration—as the image of the knee visually changes, we pair this with congruent touch input; if the knee appears to visually elongate and stretch, then we pull on the calf muscle at the same time. This creates a very compelling feeling that the knee is truly changing in size. We found that these illusions are analgesic—significantly more so than a touch control condition—reducing pain by approximately 20-40 percent. These findings support the idea of important links between the perceived physical body and pain.
The other major project, which is being led by my honor student Claudia Neubauer, looks at the effects of hypnosis, specifically task-motivating suggestions, on corticomotoneuronal excitability. We’re just starting this work, though, so I have no results to share, but it's interesting to study what physiological effects task-motivating suggestions provided under hypnosis may actually have.
What's the most exciting thing you've found so far?
As I mentioned, with our work on multisensory integration in back pain, we saw that people's perception of stiffness of their own back changed just by pairing a noise with the application of force. What’s exciting is that when we decreased the volume of the creaky noise, we saw an opposite effect on perception—they were less protective of their backs and began to underestimate the force applied.
These findings are exciting because they show that people with back pain are able to integrate multisensory information. Often we think they're not very good at doing so, but they had the exact same perceptional alterations as people without back pain. That opens the door for using multisensory approaches in our treatments.
What’s the most surprising thing you’ve found so far?
We did a study using functional magnetic resonance imaging to map the size of the hand representation in the primary somatosensory cortex (S1) in people with complex regional pain syndrome (CRPS); this work was performed by Dr. Flavia Di Pietro during her PhD. All of the literature suggested that the cortical representation of the hand affected by CRPS was smaller than the representation of the unaffected, healthy hand. We found that, too, but in order to tell which representation is actually altered, this requires a comparison to a healthy control sample. We found the S1 representation size of the CRPS-affected hand was no different compared to healthy controls. Rather, the representation of the unaffected hand was much larger in patients compared with controls—we found an expanded representation of the healthy hand in people with CRPS, not a shrunken representation of the CRPS-affected hand. This raises the possibility that other factors, such as how the brain hemispheres interact, might be important in CRPS. It opens up a whole set of new questions.
What future projects do you have planned?
I'm becoming quite interested in looking at the idea of implicit bias and how it might influence behavioral choices. There are many things going on outside of conscious awareness that affect our decisions and our behavior. For example, if you were standing next to a hill and were asked to estimate how steep the hill is, if you're wearing a heavy backpack or are fatigued, you'll estimate the hill as being steeper than you otherwise would. But you don’t realize that you are having this altered perception. This suggests that underneath our conscious awareness are processes that take into account the state of our body and everything around us, which then alters our perceptions of the world. I think this has real implications for things like exercise where we inherently make a choice as to whether or not we can perform an activity given our abilities and the environmental challenges. What if this choice was really being largely influenced by processes occurring outside of our awareness?
Where is the field of low back pain research headed?
Hopefully toward a better understanding of pain mechanisms. An interesting example of this is David Yarnitsky’s work on pain modulatory profiles—the idea that inherent pain modulatory systems can either work well or not work well in different people. This involves testing inhibitory and facilitatory nociceptive mechanisms such as conditioned pain modulation and temporal summation. Mapping out people's profiles in this regard may well help us to understand which treatments will work in which specific individuals. One of the real challenges, particularly for low back pain, is that we have this huge "nonspecific back pain" label that encompasses approximately 85 percent of people, which makes it difficult to know the type of treatment people should receive. Having ways to evaluate different potential pain mechanisms is an interesting and fruitful path to go down.
In terms of the clinic, the real challenge is always to take treatments that have been shown to work in research settings and integrate them within the confines of a healthcare system. We know from some of the studies we've done on the importance of explaining the neurobiology of pain to chronic pain patients that in order to improve their pain levels and/or ability to function, most people in the studies receive a three-hour intensive session, one-on-one. When you look at how our healthcare system is set up in most places, often that's not feasible.
The challenge is to find ways to alter some of those treatments in order to fit them into the healthcare system or lobby to change the system. If you can show that explaining to patients what occurs in chronic pain can prevent pain from becoming chronic, that would be incredibly important for sufferers and also for cost savings. We’re actually performing a trial now in people with subacute low back pain in Sydney, led by Dr. James McAuley. This trial is specifically looking to see if education can prevent the onset of chronic pain.
What treatments actually work for chronic low back pain?
There’s evidence that pretty much any type of exercise, as long as it's properly supervised, has an effect similar to other active interventions, and probably a small effect compared to placebo, although true placebo is hard to test in exercise! For back pain, there’s also evidence that education and conceptual change interventions such as Explain Pain are helpful. Explain Pain aims to explain the physiology behind nociception and how this differs from pain, what central sensitization is, how pain modulatory mechanisms work, how beliefs and emotions can contribute to pain, and why patients will sometimes experience the symptoms they have. A recent systematic review showed it to be helpful for decreasing disability and pain catastrophizing, amongst other outcomes. But for many other treatments, such as more invasive ones like surgery, there is little evidence that they provide a long-term benefit.
What is Body in Mind?
Body in Mind is a blog started by Lorimer Moseley, and its main goal is to promote better understanding of pain science by bringing together clinicians and researchers, and potentially patients as well, to engage in a discussion about research findings and to bring light to research projects that might get overlooked but certainly merit a discussion. The main goal isn't always to completely change practice, because we often shouldn't do that based just on one study. It’s more to ask, What did the study tell us? What things will be important to follow up? We often get authors of studies to write blog posts for Body in Mind, and it’s a unique opportunity for them to interact with people they might not ordinarily interact with.
There is also a Body in Mind research group, which is located out of the University of South Australia, and we also have an affiliate group, led by Dr. James McAuley, in Sydney at Neuroscience Research Australia. The main goal of the research within this group is to better understand clinical pain. We use experimental pain models as well as clinical pain populations to look at the relationship between the brain and the body, and try to understand what role factors like expectations or beliefs play in the pain experience.
What is the biggest challenge facing young scientists?
I think funding shortages are the biggest challenge. There is extreme competition for a finite number of positions, which is something that’s changed over time. When we speak to our mentors or to people who finished their PhDs 15 to 20 years ago, they were applying when one-third of grants got funded. Now, in all of health and medicine in Australia, that number is only 5 percent—only five out of 100 grants will be funded even though there are so many good projects and good people doing those projects.
Bridging the gap between early and mid-career is particularly challenging because there are more early-career fellowships available; as you move up in your career in Australia, there are fewer and fewer fellowships available to sponsor research-only positions. It’s really hard for an early-career researcher to get a big grant that you need to advance further, because you’re competing against more senior researchers. But I think that much of the problem for young researchers is that nothing is certain—having a job that only lasts for three or four years at a time of your life when you need things to be a bit more certain is difficult. It’s also hard to move around all the time because you often have a partner that may not be able to move, given his or her own profession.
But there is more attention to this issue now in Australia, including the creation of a grant category for early-career researchers, where they will be judged separately from more senior researchers. That’s quite important, because if senior researchers are the only successful grantees, fewer new ideas will be coming through, and when they retire, there will be no one to fill their place because we've all had to go somewhere else. Still, research is also a very rewarding career, so it balances out.
If you could have dinner with one scientist, living or dead, in the pain field or outside of the pain field, who would it be and why?
I would choose a living scientist outside of the pain field, the Nobel Laureate Elizabeth Blackburn, who won the Nobel Prize for her work on the telomerase enzyme. When you look at her accomplishments, you almost have to blink your eyes a couple of times because they are so impressive. But she made many of those accomplishments at a time when it was probably a fair bit harder for female researchers, which makes her achievements even more impressive. I'd love to pick her brain and ask her how she made different decisions in her career, and what role serendipity played, because I think what often happens is that an amazing opportunity comes up and you’re brave enough to take it; you didn’t necessarily plan it. This human element is just as intriguing to me as the science.
When you are not doing science, what are you doing? Any hobbies?
I’m an outdoors person, and an avid runner and hiker. I was also on the wrestling team for the University of Alberta in Canada, which was very good fun, and where I realized that, even when you think you're completely tired, you have more to give. Also, now that I’m living in South Australia, which has beautiful wine regions in every single direction, I'm becoming slightly more discerning in my taste.
