Looking for an excuse to sleep a little later in the morning? Researchers offered a good one - extra sleep helps people learn better.

The team at Harvard University found that people who learned a new skill, and then slept well, were better at the task the next day. "We would train people in the evening before they went to bed in our sleep lab, and record their sleep across the night, and the next morning wake them up and test them and, lo and behold, they would be 20 percent better on average", Matthew Walker, the neuroscientist who led the study, said.

The idea that sleep helps learning is nothing new, but Walker’s team, writing in the July 3 issue of Neuron, said they had shown how much it helps. "We tested about 62 subjects in total in various small experiments," Walker said. The group trained in the morning and then re-tested 12 hours later were able to improve their performance by about 2 percent," he said. The performance of those trained in the evening and re-tested 12 hours later, after a good night’s sleep, improved far more significantly - an average of 20 percent.

The test was simple - they had to use their non-dominant hand and type out a repeated sequence of keys on a computer keyboard. "What they had to do was try and execute that particular sequence over and over again as quickly and accurately as possible," Walker said.

When the researchers analysed the sleep pattern, they found a one-over-looked phase of sleep, called stage 2 sleep, seemed particularly important. This is the stage everyone goes through when heading into deep, restorative sleep, and then back up into rapid eye movement, or REM sleep - the stage during which dreaming occurs.

"You spend about 50 percent of your night in stage 2 non-REM sleep," Walker said. Then the researchers looked at timing. "What we found is that the most critical time, it seemed, for this learning is in the last quarter of the night. Let’s live in a fantasy world where we all get eight hours of sleep - that would make the last two hours the most important," he added. "The is the part of a good night’s sleep that many people will cut short by getting up early."

(courtesy: Reuters)

A study by scientists in Finland has found that mobile phone radiation could cause changes in human cells that might affect the brain. Darius Leszcznski, who headed the two-year study and will present findings soon, said more research was needed to determine the seriousness of the changes and their impact on the brain or the body.

The study at Finland’s Radiation and Nuclear Safety Authority found that exposure to radiation from mobile phones could cause increased activity in hundreds of proteins in human cells grown in a laboratory, he said. "We know that there is some biological response. We can detect it with our very sensitive approaches, but we do not know whether it can have any physiological effects on the human brain or human body," Leszczynski said.

Nonetheless, the study, the initial findings of which were published in the scientific journal Differentia-tion, raises new questions about whether mobile phone radiation could weaken the brain’s protective shields against harmful substances.

According to research, breast-fed babies may grow up to be smarter adults. Most previous studies did not measure breast-feeding’s effects on IQ into adulthood. The few that did so ignored factors such as parents’ education and social status, said the researchers, who took such factors into account.

In their study of 3,253 Danish men and women, the more babies were breast-fed through nine months of age, the higher they scored on intelligence tests in their late teens and 20s.

The link can probably be explained by the effect of nutrients in mothers’ milk on the developing brain and benefits from the close physical and psychological relationship breast-feeding involves, researchers said. Mothers who take time to breast-feed may spend more time interacting with their youngsters throughout childhood, which also could affect intelligence, the researchers said. The study found that those children who had been breast-fed for seven to nine months scored an average of about six points higher on IQ tests than those whose mothers said they nursed for less than one month.

Study director, June Machover Reinisch insisted that the studies could be the difference "between normal and bright-normal, or bright-normal and superior children.