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People can learn during sleep


A new Weizmann Institute study has found that if certain odors are presented after tones during sleep, people will start sniffing when they hear the tones alone – even when no odor is present – both during sleep and, later, when awake.

This indicates that people can learn new information while they sleep, and this can unconsciously modify their waking behaviour.

Sleep-learning experiments are notoriously difficult to conduct. For one thing, one must be sure that the subjects are actually asleep and stay that way during the “lessons.”

The most rigorous trials of verbal sleep learning have failed to show any new knowledge taking root. While more and more research has demonstrated the importance of sleep for learning and memory consolidation, none had managed to show actual learning of new information taking place in an adult brain during sleep.

Prof. Noam Sobel and research student Anat Arzi, together with Sobel’s group in the Institute’s Neurobiology Department in collaboration with researchers from Loewenstein Hospital and the Academic College of Tel Aviv – Jaffa, chose to experiment with a type of conditioning that involves exposing subjects to a tone followed by an odor, so that they soon exhibit a similar response to the tone as they would to the odor.

Now, underwater videogame for fish

Researchers at Princeton University have developed a video game to study the behaviour of fish.

The simple game, which is based on the type of prey favoured by the predatory bluegill sunfish, featured red dots that moved and swarmed in different ways against a translucent screen.

When they projected the game into a fish tank, they found that the fish were less likely to try to attack the dots when they moved in a group formation.

“By creating an immersive video game for the fish we were able to have complete control over the parameters,” senior researcher Dr Iain Couzin from the Department of Ecology and Evolutionary Biology at Princeton University told BBC News.

The size and colour of the simple prey graphics were carefully designed, he said.
He said it was important that the game had been coded so that the movement of the dots did not become predictable.

“In any computer game if you have one type of enemy it’s easy to learn. It would be fascinating to understand whether the fish learned to play the game better over time,” said Couzin.

The team is now looking at using 3D technology to create a more photorealistic world in which to study fish behaviour.

Manipulating gut flora could help tackle obesity
Researchers including one of Indian origin have claimed that vaccines and antibiotics may someday join caloric restriction or bariatric surgery as a way to regulate weight gain.
Bacteria in the intestine play a crucial role in digestion. They provide enzymes necessary for the uptake of many nutrients, synthesize certain vitamins and boost absorption of energy from food.


Fifty years ago, farmers learned that by tweaking the microbial mix in their livestock with low-dose oral antibiotics, they could accelerate weight gain.

More recently, scientists found that mice raised in a germ-free environment, and thus lacking gut microbes, do not put on extra weight, even on a high-fat diet.

In the new study, which focused on the interactions between diet, the bacteria that live in the bowel, and the immune system, a research team based at the University of Chicago was able to unravel some of the mechanisms that regulate this weight gain.
They focused on the relationship between the immune system, gut bacteria, digestion and obesity. They showed how weight gain requires not just caloric overload but also a delicate, adjustable — and transmissible — interplay between intestinal microbes and the immune response.

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