One Blog for the Kids!: Germany

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Wednesday, February 9, 2011

Sleep makes better memories

Memories take hold better during sleep
Posted: 24 January 2011

PARIS : The best way to not forget a newly learned poem, card trick or algebra equation may be to take a quick nap, scientists surprised by their own findings reported Sunday.

In experiments, researchers in Germany showed that the brain is better during sleep than during wakefulness at resisting attempts to scramble or corrupt a recent memory.

Their study, published in Nature Neuroscience, provides new insights into the hugely complex process by which we store and retrieve deliberately acquired information - learning, in short.

Earlier research showed that fresh memories, stored temporarily in a region of the brain called the hippocampus, do not gel immediately.

It was also known that reactivation of those memories soon after learning plays a crucial role in their transfer to more permanent storage in the brain's "hard drive," the neocortex.

During wakefulness, however, this period of reactivation renders the memories more fragile.

Learning a second poem at this juncture, for example, will likely make it harder to commit the first one to deep memory.

Bjorn Rasch of the University of Lubeck in Germany and three colleagues assumed that the same thing happens when we sleep, and designed an experiment to find out if they were right.

Twenty-four volunteers were asked to memorise 15 pairs of cards showing pictures of animals and everyday objects. While performing the exercise, they were exposed to a slightly unpleasant odour.

Forty minutes later, half the subjects who had stayed awake were asked to learn a second, slightly different pattern of cards.

Just before starting, they were again made to smell the same odour, designed to trigger their memory of the first exercise.

The 12 other subjects, meanwhile, did the second exercise after a brief snooze, during which they were exposed to the odour while in a state called slow-wave sleep.

Both groups were then tested on the original task.

Much to the surprise of the researchers, the sleep group performed significantly better, retaining on average 85 per cent of the patterns, compared to 60 per cent for those who had remained awake.

"Reactivation of memories had completely different effects on the state of wakefulness and sleep," said lead author Susanne Diekelmann, also from the University of Lubeck.

"Based on brain imaging data, we suggest the reason for this unexpected result is that already during the first few minutes of sleep, the transfer from hippocampus to neocortex has been initiated," she said in an email exchange.

After only 40 minutes of shuteye, significant chunks of memory were already "downloaded" and stored where they "could no longer be disrupted by new information that is encoded in the hippocampus," she explained.

Diekelmann said the positive impact of short periods of sleep on memory consolidation could have implications for memory-intensive activities such as language training.

The findings, she said, also point to a strategy for helping victims of post-traumatic stress syndrome, a debilitating condition caused by extreme experiences.

The reactivation techniques "might prove useful in re-processing and un-learning unwanted memories," she said. "And reactivation of newly learned memories during ensuing sleep could then help consolidate the desired therapeutic effects for the long-term."

Diekelmann cautioned that computers are an imperfect metaphor for the way memories are stored in the brain.

"Human memory is absolutely dynamic. Memories are not statically 'archived' in the neocortex but are subject to constant changes by various influences," she said.

Likewise, the act of remembering does not simply entail "reading" the stored data, she added. "Recall is a reconstructive process in which memories can be changed and distorted."

- AFP/sh

Taken from ChannelNewsAsia.com; source article is below:Memories take hold better during sleep

Wednesday, June 23, 2010

How to dull the brain

This may be one study that proves the old, old saying:

"Better to be the rat among the cats,
than to be the cat among the rats."

Read on...
-----

Brain patterns predict mistakes: study

CHICAGO - It turns out that dull tasks really do numb the brain. Researchers have discovered that as people perform monotonous tasks, their brain shifts towards an at-rest mode whether they like it or not.

And by monitoring that area of the brain, they were able to predict when someone was about to make a mistake before they made it, a study published Monday in the Proceedings of the National Academy of Sciences found.

"There's this thing that's probably intrinsic where your brain says I do need to take a little break here and there's nothing you can do about it," said study author Tom Eichele of Norway's University of Bergen.

"Probably everyone knows that feeling that sometimes your brain is not as receptive or as well performing and you didn't do anything to actually induce that."

When that happens, blood flows into the part of the brain which is more active in states of rest.

And since this state begins about 30 seconds prior to a mistake being made, it could be possible to design an early-warning system which could alert people to be more focused or more careful, Eichele said.

That could significantly improve workplace safety and also improve performance in key tasks such as airport security screening.

"We might be able to build a device (that could be placed) on the heads of people that make these easy decisions," he told AFP.

"We can measure the signal and give feedback to the user that well, your brain is in the state where your decisions are not going to be the right one."

Eichele and his colleagues in the United States, Britain and Germany were able to detect these brain patterns with MRI scans, which are not portable.

The next step is to see if more mobile EEG devices are able to detect the phenomenon.

A prototype of a wireless, mobile, and lightweight EEG amplifier is currently in development and could be ready for the market in 10 to 15 years, he said. - AFP/ar

From ChannelNewsAsia.com; source article is below:Brain patterns predict mistakes: study
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Thursday, July 2, 2009

Myanmar fossil may shed light on evolution

Image via Wikipedia

07/02/2009 | 08:53 AM

BANGKOK, Thailand – Fossils recently discovered in Myanmar could prove that the common ancestors of humans, monkeys and apes evolved from primates in Asia, rather than Africa, researchers contend in a study released Wednesday.

However, other scientists said that the finding, while significant, won't end the debate over the origin of anthropoids — the primate grouping that includes ancient species as well as modern humans.

The pieces of 38 million-year-old jawbones and teeth found near Bagan in central Myanmar in 2005 show typical characteristics of primates, said Dr. Chris Beard, a paleontologist at the Carnegie Museum of Natural History in Pittsburgh and a member of the team that found the fossils.

"When we found it, we knew we had a new type of primate and basically what kind of primate it was," Beard said in a telephone interview from Pittsburgh. "It turns out that jaws and teeth are very diagnostic. ... They are almost like fingerprints for fossils like this."

The findings were published in the Proceedings of The Royal Society B, a London-based peer-reviewed journal.

Beard and his team from France, Thailand and Myanmar concluded that the fossils — which they dubbed Ganlea megacanina — came from 10 to 15 individuals of a new species that belonged to an extinct family of Asian anthropoid primates known as Amphipithecidae.

Wear and tear found on the canine teeth suggest the tree-dwelling, monkey-like creatures with long tails used their teeth to crack open tropical fruit to get to the pulp and seeds — behavior similar to modern South American saki monkeys that inhabit the Amazon basin, Beard said.

"Not only does Ganlea look like an anthropoid, but it was acting like an anthropoid 38 million years ago by having this feeding ecology that was quite specialized," Beard said.

His team determined that the fossil was 38 million years old, making it several million years older than any anthropoid found in Africa and the second-oldest discovered in Asia.

In 1994, Beard and his Chinese colleagues found fossilized foot bones of the anthropoid Eosimias — one of the worlds smallest primates — which lived between 40 million and 45 million years ago and roamed ancient rain forest on the eastern coast of China.

Beard said the age of both fossils was the evidence he needed to challenge contentions that anthropoid primates had evolved in Africa, where Lucy, a 3.2 million-year-old fossil, was discovered in 1974.

"This new fossil Ganlea definitely helps us argue — and we think the argument is pretty close to settled now — that when you go back this far in time, the common ancestor of monkeys, apes and humans was definitely in Asia, not in Africa," Beard said.

In May, researchers unveiled a nearly intact skeleton of a 47 million-year-old primate — found in Germany and dubbed "Ida" — that they said provides a glimpse into how our distant ancestors may have looked.

"We wouldn't claim Ganlea is missing link, but we know Ganlea is much more closely related to our ancestors than Ida ever was — even though, unfortunately, we don't have complete skeleton like they did for Ida," he said.

Jorn Hurum, who brought Ida to the University of Oslo Natural History Museum, said that it was too early to draw conclusions from the Myanmar fossils because only jawbones and teeth were found.

"These fragments are still too few and far between," Hurum said. "This is the kind of scientific debate that will continue until more complete skeletons like Ida has been found, and this may take several hundred years."

Stony Brook University Prof. John G. Fleagle, a paleontologist, said the discovery of Ganlea is important because it shows how several different primates found in Myanmar are related and provides interesting suggestions about a unique dietary specialization.

But he said the Myanmar fossils do little to prove whether anthropoids evolved in Asia or Africa — or even whether Ganlea was an anthropoid or an early relative of lemurs.

"This doesn't add anything new about whether anthropoids came from Africa or Asia or the broader evolutionary relationships of these particular primates ," Fleagle said.

"The definitive features that would resolve it in people's mind would be in the skull," he said. "Without a skull to demonstrate the distinctive anthropoid features of the eye and ear regions, scientists will still continue to debate whether the dental similarities just indicate similar diets or are the result of a common heritage."

Beard isn't letting the criticism slow him down. He and his team expect to return in November to Myanmar to continue searching for more fossils and exploring how anthropoids evolved in Asia and then migrated to Africa.

"The question is when and how did this big evolutionary shift occur from Asia to Africa," Beard said. "That is something we are trying to establish. We have a team working in Myanmar which has ideas of places to go in Africa to try and pick up thread there." - AP

From GMANews.tv; see the source article here.

Tuesday, May 19, 2009

Scientists piece together human ancestry

Updated 35 minutes ago

The fossil is believed to be an ancestor of monkeys, humans and other primates.

(CNN) -- Scientists hailed Tuesday a 47-million-year-old fossil of an ancient "small cat"-sized primate as a possible common ancestor of monkeys, humans and other primates.

Scientists say the fossil, dubbed "Ida," is a transitional species, living around the time the primate lineage split into two groups: A line that would eventually produce humans, primates and monkeys, and another that would give rise to lemurs and other primates.

The fossil was formally named Darwinius masillae, in honor of the anniversary of Charles Darwin's 200th birthday.

"This is the most complete primate fossil before human burial," said Dr. Jorn Hurum, of the Natural History Museum at the University of Oslo, who led the study of the fossil, a young female primate.

"And it's not a few million years old; it's 47 million years old," Hurum said, speaking at a news conference at the American Museum of Natural History in New York.

The fossil was discovered in 1983 in the Messel Pit, Germany, near Frankfurt, and had been until recently in private collections, according to an article published Tuesday in the scientific journal PLoS ONE, a publication of the Public Library of Science. Read the report from PLoS ONE

However, because it was split into two parts, its significance was not immediately recognized.

An international team of scientists, which Hurum led, conducted a detailed forensic analysis of the fossil for the past two years, the release said.

Hurum nicknamed the fossil Ida after his young daughter, he said.

The fossil's body is nearly complete; only part of one leg is missing, according to Hurum. In addition to the bones, the softer features are also preserved, as are the remnants of its last meal: fruits, seeds and leaves, which were found in Ida's gut, according to the scientists.

"It's such a beautiful specimen," Hurum said of Ida. He said the fossil is about 2 feet long, "like a small cat in size."

The fossil has both adult and baby teeth, indicating that it was weaned and about 9 months old when it died, the PLoS article said.

She would have eventually grown to the size of a lemur, the article said.

The young primate fossil does not have two crucial anatomical features found in lemurs: a grooming claw on the second digit of its foot and a fused row of teeth in the middle of its lower jaw, known as a toothcomb, the scientists said.

X-rays revealed a broken wrist, which the team of scientists believe may have contributed to Ida's death, according to a news release from the museum at Oslo.

Ida may have been overcome by carbon dioxide gas while drinking from the Messel lake, which was often covered by a low-lying blanket of the gas, the news release said. Hampered by the broken wrist, the young primate may have fallen into unconsciousness and may have slipped into the lake. The primate sunk to the bottom and was preserved for 47 million years, the news release said.

(See the press release video here).

From CNN.com; see the source article here.