Will future Mars explorers be able to overcome the cognitive problems associated with long journeys under heavy conditions? Image by Nicolas Lobos / Unsplash.
Astronauts on long space missions may experience a cognitive decline that makes them slower to read emotions on other people’s faces and more likely to perceive facial expressions as angry. According to a new study conducted by scientists at the University of Pennsylvania and the German Aerospace Center (DLR), published on March 17, 2021, in the peer-reviewed journal Frontiers in physiology.
In their study, the scientists subjected people to simulated weight for two months and tested their cognitive abilities, such as finding a single element that does not belong to a group of objects or memorizing 10 shapes. In these cognitive tests, participants showed an initial decrease in speed, but then remained unchanged over time. The exception was the recognition of emotions or the ability to describe the emotion on someone’s face in a photograph, which continued to deteriorate. The decline of these types of skills, say researchers, could have serious consequences for the well-being of a crew on a long mission to Mars, due to the essential need for teamwork and harmony in such a precarious mission.
The study details the experiments performed to test cognitive functioning in a long mission to Mars. The study had 24 subjects who spent 60 days locked in bed, with their heads tilted down 6 degrees, to simulate a weightless environment. Some of the participants also suffered 30 minutes a day in a centrifuge to simulate short periods of gravity, a method that could be used in space to help counteract the effects of weight.
Resting upside down at a slight angle of 6 degrees is the standard way to simulate the effects of microgravity on Earth. Image via DLR.
Subjects tested in the centrifuge are spun to experience artificial gravity. Image via DLR.
In this long-exposure photo, the bright lights show the movement of the rotating centrifuge. Image via DLR.
Participants completed cognitive tests, along with a short survey of alertness and mood, before, during and after rest periods with the bed tilted. At first, subjects showed signs of slowing cognitive function, but only one experienced factor tested for – emotion recognition performance – continued to decline throughout the study. The more participants spent time in the reclining position with their head down, the more they had to recognize their facial emotions. They also reported seeing more negative emotions on their faces during and after the study than before starting the antigravity simulations.
The task of recognizing emotions measures how well the participant recognizes the emotions in facial expressions. Study participants would look at photos of professional actors showing a variety of emotions on their faces. Then, participants labeled the expressions as happy, sad, angry, fearful, or neutral. An in-depth analysis showed that participants were significantly less likely to rate their faces as happy or neutral and more likely to rate them as upset with the increase in time spent in antigravity simulation.
Being able to work together in space will be the key to the success of any mission. Misreading emotional cues has all the hallmarks of a dramatic space work. But the threat is real. As Mathias Basner of the University of Pennsylvania, lead author of the cognitive and antigravity study, said:
The ability of astronauts to “read” each other’s emotional expressions correctly will be of paramount importance for effective teamwork and mission success. Our findings suggest that their ability to do so may be affected over time.
Mathias Basner of the University of Pennsylvania was the lead author of the study that looked at the cognitive effects astronauts might experience on a mission to Mars. Image via the University of Pennsylvania.
In order for space astronauts to feel the effects of gravity and probably combat some of the associated cognitive decline, either the spacecraft or the astronauts themselves should be rotated to induce artificial gravity. None of these methods have yet been used in space practice. But the 30 minutes a day in a centrifuge to simulate artificial gravity had no positive effect on the participants in this test.
The results of the study on the harmful effects on the knowledge of astronauts under heavy conditions raise questions about astronauts who are already in space for long periods of time. EarthSky asked Basner, “Is this an effect that space station astronauts are currently facing?” He answered:
We don’t know that. Astronauts spend more on the International Space Station (ISS) than subjects exposed to bed rest in our study. However, the ISS is currently the size of a 4-bedroom house and there are plenty of ways astronauts can connect with their loved ones on the ground. We have some data to test the recognition of emotions in a very limited number of ISS astronauts, but the number of astronauts will have to increase in the next few years.
EarthSky also asked Basner about the difference between a long mission to Mars and astronauts who spent a year or two in space on the International Space Station. He said:
There are only 4 astronauts who have spent more than a year in a row on the ISS! The mission to Mars will be much longer (~ 3 years), the spacecraft much smaller, the crew smaller (probably 3 or 4), no rescue possibilities, radiation exposure is a much bigger problem and communication delays. So the mission to Mars will be much more stressful.
The effects of microgravity media on astronauts’ cognitive emotional responses is an area that still needs further study. Alexander Stahn of the University of Pennsylvania was one of the scientists in the study. Stahn said:
We cannot say whether the effects observed in the emotion recognition test were induced by simulated microgravity or by the isolation and isolation inherent in the study, with separate bedrooms and sporadic contact with the study team. Future studies will have to deal with these effects.
But the possible link between weight and decreasing ability to read someone’s emotions is an important one that still needs to be addressed. The study stated:
The relevance of the space flight of a deterioration in emotional processing with increasing mission time cannot be overstated, especially for space exploration missions, where astronauts will be limited to a small space with a small group of colleagues for up to 3 years. .
Conclusion: A study showed that people subjected to 60 days of simulated weight had a slower ability to read the emotions on people’s faces, often seeing anger there compared to before the start of testing.
Source: Continuous and intermittent artificial gravity as a countermeasure to the cognitive effects of 60 days of rest in a bed tilted upside down
