Catnap helps you live longer

A 45-minute catnap helps lower blood pressure, American researchers reported last week. They said a daytime snooze could improve heart health, particularly if you’re not getting as much sleep as you should at night. This follows a recent six-year Greek study which found that people who took a 30-minute siesta at least three times a week appeared to have a 37 per cent lower risk of heart-related death.

The theory is that napping, by encouraging you to relax, reduces blood pressure. It can also help your brain. A study by the University of California found that after a 90-minute daytime sleep, volunteers performed better in complicated written tests than those who were kept awake. The study leader, Dr Matthew Walker, says napping works over and beyond helping you catch up on lost sleep: ‘At a neuro-cognitive level, it moves you beyond where you were before you took a nap.’

This has been backed up by research on pilots which shows that a 26-minute in-flight nap (during which the plane is manned by a co-pilot) enhances performance by 34 per cent and overall alertness by 54 per cent.

The researchers suggest the brain uses this snatched extra sleep to help it process short-term memories (effectively moving them into a longer-term storage area in the brain), creating ‘space’ for new facts to be learned. But it’s not just enough to put your head down. Here, we show you the right way to nap.

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http://nation.com.pk/pakistan-news-newspaper-daily-english-online/Entertainment/10-Mar-2011/Catnap-helps-you-live-longer/1

Humans, Like Animals, Are Fearless Without Amygdala

In the 1930s, researchers discovered that when a certain part of monkeys’ brains were removed, the animals became fearless. They approached snakes, started batting them around like sticks and played with their hissing tongues.

This experiment has been repeated in animals numerous times, and the scientific consensus is that when the amygdala is removed, an animal loses any sense of fear.

Now, scientists have confirmed that a missing amygdala results in similar behavior in humans, according to a study in the journal Current Biology.

“There’s not very many humans with this sort of brain damage,” said Justin Feinstein, the study’s lead author and a clinical neuropsychologist at the University of Iowa. “Luckily for us, we had access to a patient, SM, and we studied her different fear behaviors and we read her personal diaries.”

Patient SM, due to a rare condition called lipoid proteinosis has holes where her amygdala would normally reside. Researchers found that she, like the monkeys, has no fear of creatures like snakes and spiders, which ordinarily alarm people.

But while this behavior is relatively benign, the researchers also found SM putting her life at risk. In one instance, she walked through a park alone at night and was attacked by a man with a knife.

“The following day, she again walked through the same park,” Mr. Feinstein said.

Mr. Feinstein and his colleagues are trying to coach the patient to behave in a more cautious manner. They also believe that understanding how the mind of a patient like SM works could help researchers develop therapies for individuals who express excessive amounts of fear, like war veterans.

“We may be able to dampen the effects of the amygdala,” he said. “We can do that through psychotherapy and possibly through medication.”

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http://www.nytimes.com/2010/12/21/science/21obbrain.html