Artist’s rendition of astronauts on Mars. (NASA)

Traveling into deep space could accelerate the onset of Alzheimer’s disease, an incurable form of dementia, according to a new report.

The NASA-funded study assessed how cosmic radiation would impact the astronauts throughout their trip in deep space. The effect of cosmic radiation on the human body has been a  concern for the US space agency as it plans manned missions into deep space, such as one to a distant asteroid in 2021, and another to Mars in 2035.

Earth’s magnetic field usually keeps us, and those in low Earth orbit, safe from the perils of cosmic radiation. However, beyond Earth’s protective magnetic fields, space travelers are exposed to a constant barrage of radiation.

With adequate warning, such as in the case of solar flares, steps can be taken to protect astronauts from dangerous forms of radiation. However, other forms of cosmic radiation, which occur without warning, cannot be blocked as effectively.

“Galactic cosmic radiation poses a significant threat to future astronauts,” said M. Kerry O’Banion,  a professor in the University of Rochester Medical Center (URMC) and senior author of the study. “The possibility that radiation exposure in space may give rise to health problems such as cancer has long been recognized. However, this study shows for the first time that exposure to radiation levels equivalent to a mission to Mars could produce cognitive problems and speed up changes in the brain that are associated with Alzheimer’s disease.”

Artist’s illustration of the shape and function of the Earth’s magnetic field that protects us from harmful cosmic radiation (NASA)

In the past,  scientists studied the impact of cosmic radiation on a living being’s cardiovascular and musculoskeletal systems, as well as potential risks of contracting various forms of cancer.But the new study,  published in  PLOS ONE, examined the possible effects of space radiation on neurodegeneration, a gradual loss of brain structure or function.

For this study, researchers wanted to find out what role, if any, cosmic radiation plays in accelerating the biological and cognitive indicators of Alzheimer’s disease, especially in those  predisposed to developing the illness.

They specifically wanted to learn more about the impact of radiation from high-mass, high-charged (HZE) particles, which come in many forms and travel through space with the force of exploding stars.

Instead of examining hydrogen protons, which are produced by solar flares, the researchers decided to study iron particles. They say HZE particles, such as iron, when combined with their high rate of speed, are able to go through solid objects, like a spacecraft’s walls and protective shielding.

“Because iron particles pack a bigger wallop, it is extremely difficult, from an engineering perspective, to effectively shield against them,” said O’Banion. “One would have to essentially wrap a spacecraft in a six-foot block of lead or concrete.”

Brain affected by Alzheimer’s Disease (left) vs normal brain (right) – (US Dept of Veterans Affairs)

The researchers exposed mice to various doses of radiation, including levels that would be similar to what astronauts would experience during deep space voyages.To evaluate the cognitive and biological impact of the radiation exposure, the mice were then put through a series of experiments in which they had to recall objects or specific locations. Researchers observed that the radiation- exposed mice were much more likely to fail these tests, suggesting neurological impairment, earlier than the symptoms would typically appear.

Along with symptoms of neurological damage, the researchers found that the mice’s brains also showed signs of vascular changes and had a greater than usual buildup of beta amyloid, the protein “plaque” that gathers in the brain and is one of the characteristics of Alzheimer’s Disease.

“These findings clearly suggest that exposure to radiation in space has the potential to accelerate the development of Alzheimer’s disease,” said O’Banion. “This is yet another factor that NASA, which is clearly concerned about the health risks to its astronauts, will need to take into account as it plans future missions.”

(Images: Jossifresco via Wikimedia Commons/Creative Commons)

People who consider themselves highly religious are less motivated by compassion than non-believers, according to a new study from the University of California at Berkeley

After conducting three experiments, social scientists found that people who considered themselves to be “less religious” were consistently driven by compassion to be more generous to those in need.

As far as those described as being “highly religious”, researchers found that their measure of generosity was largely unrelated to how generous they were.

Compassion is defined by the study “as an emotion felt when people see the suffering of others which then motivates them to help, often at a personal risk or cost.”

“Overall, we find that for less religious people, the strength of their emotional connection to another person is critical to whether they will help that person or not,” said UC Berkeley social psychologist Robb Willer, a co-author of the study. “The more religious, on the other hand, may ground their generosity less in emotion, and more in other factors such as doctrine, a communal identity, or reputational concerns.”

Although the Berkeley study, published in Social Psychological and Personality Science, examined the connection between religion, compassion and generosity, it did not directly study the reasons for why highly religious people are less compelled by compassion to help others.

Researchers involved with the study do theorize however, that a sense of moral obligation, rather than compassion, drive religious people more strongly than those who are more non-religious.

Size matters to female crickets

(Image: Open Clip Art Library)

It turns out the size of a male cricket matters to female crickets, and the male crickets aren’t above faking it to attract a mate, according to a new study from England’s University of Bristol.

To attract females, male crickets sing loud and repetitive songs at night by rubbing their wings together. This sets the wings into a resonant vibration, which produces a loud and intense sound, allowing the female crickets to find them.  The lady crickets also listen for this sound in order to find the hottest guys.

The male cricket mating song contains many cues females can use to assess their desirability. However, most have thought the one attribute that couldn’t be faked or augmented was the sound which indicates the cricket’s size.

Males communicate their size through their mating song.  Lower pitched sounds are usually produced by larger males, while the sounds the smaller guys produce have a higher pitch. So, the females – who prefer larger male crickets – simply listen for those lower-pitched sounds to find the guy cricket of their dreams.

Experts have always thought the smaller males were stuck with making the high pitched, squeaky sounds.  But the study found that tiny and nearly transparent tree crickets, said to be highly unusual creatures, use temperature to change the pitch of their song making them sound much bigger than they really are.

Warmer temperatures made the tree crickets livelier and they called faster, producing sounds in a higher frequency mode. However, when it was cooler, the crickets behaved in the opposite manner, producing lower-pitched sounds making them sound much bigger than they really were, allowing the little guys to attract females.

Speaking more than one language fine-tunes hearing and enhances attention

(Image: Flickr/Creative Commons)

Speaking more than one language can enhance attention and working memory, according to a new study from Northwestern University, by fine tuning a person’s auditory nervous system, allowing them to manipulate verbal input.

The study’s research, led by Northwestern University’s bilingualism expert Viorica Marian and auditory neuroscientist Nina Kraus, found that speaking more than one language changes how the nervous system responds to sound.

“People do crossword puzzles and other activities to keep their minds sharp,” Marian said. “But the advantages we’ve discovered in dual language speakers come automatically simply from knowing and using two languages. It seems that the benefits of bilingualism are particularly powerful and broad, and include attention, inhibition and encoding of sound.”

The researchers, working with 23 bilingual (English and Spanish speaking) teenagers along with 25 teens who only spoke English, recorded their subjects brain-stem responses to complex speech sounds under loud and quiet conditions.

Both groups had the same response when the listening conditions were quiet.  But, when it wasn’t so quiet, and there was a bit of background noise, the researchers found that the brains of the bilingual teens were much better a picking up and detecting speech sounds.

“Bilinguals are natural jugglers,” said Marian. “The bilingual juggles linguistic input and, it appears, automatically pays greater attention to relevant versus irrelevant sounds. Rather than promoting linguistic confusion, bilingualism promotes improved ‘inhibitory control,’ or the ability to pick out relevant speech sounds and ignore others.”