Human performance in extreme environments
Humans have always striven to push boundaries: to go higher, further, faster, deeper and especially where no man - or woman - has been before. And that often includes into space. In other words, into unnatural environments that humans have not evolved to accommodate. On the one hand this presents an opportunity to study human physiology at the extremes, and learn how to better manage more mundane situations and conditions back here on Earth. But on the other hand, keeping people fit, healthy and safe when they’re operating under these pressures is also a major priority. And, speaking with Chris Smith, this is what Michael Schmidt - CEO and Chief Scientific Officer at Solaris Aerospace - does for a living…
Michael - So one of the things unique to our field is we work in extreme environments. Everything from the space flight environment to military special forces or to sports where the environment is not harsh, but where the training, the competition, the physical loading, the psychological loading is very dynamic. And so they have higher risk and they have a higher demand for high performance. So any decrements and performance really can impact their ability to do their work safely and even survive. Any improvements that we can make in their ability to perform can be very important for their success in those environments. If you're operating in an extreme environment like a spacewalk and you've lost 10% of your metabolic activity, that could be very serious. And so we as precision medicine to enter that world, basically ask the question, if we measure these 500 biochemical markers that give us a picture of the landscape, what can that tell us about a way to optimise your performance? So it's like going into a forest and instead of choosing just a couple of trees to understand the health of the forest, we're gonna measure a thousand trees. We're gonna get the best possible picture, and from that, then we can prescribe what the forest needs.
Chris - Isn't one of the challenges confronting you, and people working in this sort of setting, a data problem in the sense that when you've got millions of people that you can study, doing everyday things that everyday people do, you've got plenty of data to iron out the noise. When you've got extreme circumstances with just a handful of people, there's gonna be huge amounts of noise differences between individuals, differences between the individual settings. And does that not make this much more difficult to do meaningfully?
Michael - It does in one respect, which is why we, we do it in high performance environments, as I mentioned, from space flight to NFL football, to soccer, to military special forces, et cetera. So we're constantly testing that and we're constantly measuring that. We're asking the questions in those extreme environments, you know, is what we're doing, we're detecting these changes, and then we're developing a precise intervention for them. Is it having an impact on our performance, which is constantly being measured in all kinds of ways in these different environments anyway, so we get relatively rapid feedback on what we're doing. Has it made a difference in individual and in group performance? And so you're right, there's a lot of data that comes out of that. But we broke it down also into essential inputs into a system. So if you were flying a Saturn five rocket - and we'll use the old days! - The engineers would've built that and they know what goes into it, right? All the inputs. They know well how the processes work, because they engineered those, and they know what the output is; they know what's supposed to happen. And it's that way with all engineered systems. And the human system's already been built. It's very complicated, as you know, we're trying to simplify that equation into, well, what are the essential inputs? What are the things that the body must have in order to function? Number two, what are the conditionally essential ones? What are those intermediate ones where the body normally makes them because of various circumstances, it's no longer making them sufficiently. And then what are the non-essential inputs like drugs and environmental exposures, the things that are not needed? So what of these three tiers that are going into the system are themselves creating these perturbations? I'll use one example if I may. There was a study looking at the effect of inflammation on what's called psychomotor speed. This is the speed of processing and reaction time. And if somebody throws a baseball at you, how quickly can you react to that? What they found is that the higher the levels of inflammation, the slower the reaction time. But what was interesting is that they asked the different question than of the data, and they said, well, what if we break it down, not based on age, but based on the levels of these inflammatory markers. And what they found out was, regardless of age, those with the higher levels of inflammatory chemicals had the slower reaction times, meaning that you could be in your thirties, but if your inflammatory markers were high, you might have the slower reaction time of someone who's in their seventies. So this is where understandings that some of the molecular processes that affect critical capabilities like reaction time, can help us develop a molecular map. And so across these different molecular processes, there's a wide range of things that impact things critical to performance, like reaction time. NASA did a similar study in their Hera experiment, where they simply changed the diet and they gave a regular space station diet over 45 days, and then an enhanced diet, which had a range of different nutrients, and they looked at psychomotor vigilance tasks; and those with the enhanced diet had a better psychomotor vigilance. So those are the increments that we're trying to look for.
Chris - We often find that when we look at performance in extreme circumstances, it can be extremely informative about the more mundane or the more pedestrian circumstance. Scientists went to the top of Everest and took blood from mountaineers in order to learn better how to manage people with low blood oxygen in the intensive care unit, for example. So I suppose that by having clear examples of how things operate at the extreme, you nevertheless learn quite a bit about how you can do things for the man and woman and child on the street?
Michael - Exactly. And there's three examples that could quickly go over. So one is the bone loss and muscle loss in space flights. So that's a, there's a very diligent efforts to try and reverse that, and that's informed us a great deal about bone and muscle muscle loss on earth. There's another problem called space associated neuro-ocular syndrome, which essentially because when you go in space, the fluid all floats up towards your head and you get pressure inside the cranium and inside the eyes, and you develop visual problems. Probably happens with 25 to 40% of the astronauts who are up there for four months or longer. So we're looking extensively at what are the molecular underpinnings of that? There's genetic markers that seem to make that subgroup more susceptible, and now we have a target to intervene upon. And then a new phenomenon related to that is called jugular vein stasis. So the, the large veins in the neck that are supposed to drain blood out of the cranium, out of the brain, it gets stagnant there. And then in a handful of astronauts, there's been some clotting there. So that can inform us about related phenomenon on earth.