Our brains adapt in outer space conditions and we can measure it
14 June 2017
In their newest discovery published researchers from the University of Antwerp and University of Liège show that our brains modify their activity in conditions of altered gravity, like weightlessness.
Are humans ready for space travel? We already know that outer space is not friendly to our bodies, but what about our brains? Researchers from the University of Antwerp and University of Liège, Belgium, are starting to answer this question. In their newest discovery published in Scientific Reports this week, they show that our brains modify their activity in conditions of altered gravity, like weightlessness. They discovered that when humans find themselves in atypical gravity, our brains try to combine information from unique body sensations and the surrounding world. So far, such conflicts have only been studied in controlled laboratory settings. For the first time, we have now been able to measure human brain function after exposure to altered states of gravity, during a parabolic flight.
"The brain is adapting if a conflict occurs", says Professor Floris Wuyts, research director of the Antwerp University Research centre for Equilibrium and Aerospace (AUREA) and principle investigator of the BRAIN-DTI project, funded by the European Space Agency. "That new insight can ultimately help patients with dizziness." In terms of cognitive neurosciene, “these findings help us to better understand what part of our brain is responsible for our bodily self-consciousness, that is where we are located in space”, says Dr. Athena Demertzi, post-doctoral researcher funded by the Belgian Fonds de la Recherche Scientifique (FNRS) and the French Institut National de la Santé et de la Recherche Médicale (INSERM). “An interesting question is whether our brains continue to adapt when we are in zero gravity for a long time. I am pretty confident that our great collaborative forces with the Antwerp team and the ESA partners will answer such questions soon”, points Prof. Steven Laureys, FNRS Research Director and head of the Coma Science Group, GIGA Research, University and University Hospital of Liège.
The Belgian teams, in collaboration with the Universtiy Hospital of Bordeaux (France), performed brain scans in 28 people before and after their first-time participation in a parabolic flight. During such as flight, a special airplane follows a particular track which creates phases of “hypergravity” and “microgravity” (Figure 1). Hypergravity is a state of increased gravity that occurs when the plane climbs at a certain angle, which pushes you in your seat, much like during a fast rollercoaster ride. Microgravity is a state of decreased gravity, resembling the weightlessness of zero gravity, which occurs when the plane is in free fall. The parabolic flight consists of 31 of such climbs and free falls or “parabolas” and lasts approximately 3.5 hours.
Using funtional MRI, a method which measures brain activity across time, the researchers found that a specific brain region participated less in overall brain function after the parabolic flight as compared to baseline measurements (Figure 2). Previous investigations indicated that this region, i.e. the right temporoparietal junction, plays an important role in vestibular function by, for example, helping to resolve the question “where is up and down?”, a typical experience during the phase of weightlessness. Interestingly, electrical stimulation of this area can elicit sensations of body tilt and even out-of-body experiences. This is the first study showing that altered gravity changes brain function. It therefore seems that the brain tries to fix this incompatibility. "Our findings might have implications for astronauts, who are exposed to weightlessness for a long time when residing in the International Space Station", says PhD candidate Angelique Van Ombergen, first-author of the study, funded by the Research Foundation Flanders (FWO Vlaanderen).
These results can be significant for patients with vestibular problems. Professor Wuyts concludes: "If you want to solve a problem, you must first “see” it. We can now do so. For example, I think of visually-induced dizziness. This is a form of dizziness experienced by some patients with busy visual stimuli, such as walking through the hallways of supermarkets or in busy shopping centers.” According to the researchers, their aim is to shed more light on the secrets of the human equilibrium.