Astronauts Brains Could Be Affected By Travel to Mars; Can NASA Protect Them From Such Scenario?

Various NASA-funded studies claimed astronauts' minds could be affected by their trip to Mars due to chronic radiation toxicity and other factors that could influence their moods and even their ability to think.

Also, the anatomy of astronauts' brains may be altered by space travel. Since emerging from the International Space Station (ISS), astronauts have demonstrated anatomical improvements in their minds. The brain physically moves upwards inside the head, where there is little connectivity between regions on the cortex layer of the brain and those inside the skull.

Scientists are still trying to figure out how these shifts influence behavior, but they're getting closer. Disorientation, visual illusions, coordination problems, and motion sickness are all known to affect astronauts. However, those conclusions are often focused on small samples.

Microgravity Simulation

According to a recent study published in Frontiers in Physiology, spending nearly two months in simulated weightlessness has a small but widespread detrimental impact on cognitive efficiency that brief bursts of artificial gravity can not counter.

In simulated microgravity, though cognitive speed on most tests initially decreased but then remained constant over time, emotion recognition speed deteriorated. The study, titled "Continuous and Intermittent Artificial Gravity as a Countermeasure to the Cognitive Effects of 60 Days of Head-Down Tilt Bed Rest," claimed that the participants were more likely to label facial expressions as angry rather than joyful or neutral.

Mathias Basner, the study professor who serves as a psychiatry professor in the University of Pennsylvania, astronauts' ability to correctly "interpret" each other's emotional emotions would be critical for successful teamwork and mission performance. The results, however, indicate that their capacity to do so can deteriorate over time.

For two months, the researchers asked the participants to lie on their backs at a 6° angle without moving. They were required to complete a set of cognitive exercises tailored for astronauts and applicable to spaceflight daily to assess their spatial orientation, memory, risk-taking behavior, and emotional comprehension of others.

In activities requiring sensory and motor abilities, the results revealed a modest but consistent weakening in cognitive speed. This seems to be consistent with improvements in brain tissue density found during spaceflight in the "sensorimotor cortices," the main sensory and motor regions of the brain that help process sensory signals and gestures. When staring at people's ears, participants have had trouble interpreting feelings.

Overwhelmed

According to a separate NASA-funded report published in the journal ENeuro on Aug. 5, the existence of the radiation atmosphere in space may be the single most significant barrier that humanity could overcome to move beyond Earth's orbit.

Dr. Munjal Acharya, radiation oncologist at the University of California, Irvine, and the study's lead scientist, told NBC News that radiation toxicity influences cognitive capacity and behavior at the molecular level. He suggested that the exposure could make it difficult for astronauts to respond successfully in unpredictable or stressful circumstances.

In the study titled "New Concerns for Neurocognitive Function during Deep Space Exposures to Chronic, Low Dose-Rate, Neutron Radiation," Acharya and his colleagues subjected 40 mice to radiation for six months before testing their memory and behavior.

Radiation-exposed mice were shown to be less likely to detect small differences in their surroundings than control mice in one experiment. Another study found that the radiation-exposed mice were so nervous that they "froze" in conditions when the control mice were not.

By disrupting relations between various regions of the mice's brains, the radiation tended to make it impossible for them to learn and adapt, according to Acharya.

According to J.D. Polk, NASA's chief health and medical officer, the report is a significant addition to our knowledge of the possible danger of radiation to astronauts.

In any case, NASA is now trying to minimize the number of radiation astronauts will be exposed to on future flights.

Keeping Astronauts Healthy

According to NBC, the space agency is now placing a radiation-shielding jacket to the test to reduce astronauts' exposure to radiation. And the company's latest Orion spacecraft will have a radiation-sensing instrument that will alert astronauts to a radiation surge, allowing them to shift to the center of the craft and cover themselves with supplies bags.

They may mainly use Orion for lunar flights, but the space agency can also use it to shuttle astronauts to a moon-orbiting spaceport from where they will board a larger craft known as the Deep Space Transport for a trip to Mars. Scientists at NASA's Langley Research Center in Hampton, Virginia, are currently working on developing safety measures for the latter craft.

Scientists are looking for ways to incorporate hydrogen-rich materials into the spacecraft's composition because hydrogen absorbs radiation. Water tanks could be used to cover the walls, which is one option being considered. Another choice is to use polyethylene shielding, which is the same lightweight material used to make water bottles.

The disadvantage of applying water or rubber to the Deep Space Transport is that it will make the spacecraft much heavier, according to Polk. As a result, the researchers are looking at other choices, such as making the craft its own radiation-blocking electromagnetic field - a complex and potentially expensive technology that Polk compared to the deflector shields used in "Star Trek."

NASA is curious as to how much radiation protection would be needed to protect astronauts, given the cost and weight considerations. Future testing, including animal experiments, may assist NASA in making that decision, according to Polk. Experts will pursue new research to identify the exact pathways that trigger cognitive loss to find solutions to prevent it.

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