July 14, 2008

Study Shows Sleep Increases Brain Function, Memory

Getting good quality sleep at night may help a person's memory, according to new research.

Connections between nerve cells in the brain are strengthened by sleep, which adds to both learning and memory potential, said researchers at the University of Geneva, who presented their study to a Federation of European Neuroscience Societies conference.

Overall, 32 volunteers were involved with the study.

Each participant was taught a new skill or shown images. Tasks included following a moving dot on a computer screen using a joy stick.

Meanwhile, one group was allowed to sleep for eight hours as the other group was deprived of sleep or only allowed to take a short nap.

Researchers then used functional magnetic resonance imaging to scan brain activity of participants as they repeated tasks they learned from the previous day.

Those who had slept properly performed better, and this was reflected in their brain activity.

"Our results revealed that a period of sleep following a new experience can consolidate and improve subsequent effects of learning from the experience," said Lead researcher Dr. Sophie Schwartz.

"This improvement comes from changes in brain activity in specific regions that code for relevant features of the learned material."

Although Dr. Schwartz admitted more research was necessary to make a solid conclusion, she said that sleep seemed to help the brain consolidate learned experiences and harden up weak memories which otherwise might fade in time.

It was unclear how much sleep was required to have optimum impact, Schwartz added.

"We now want to know which brain circuits are involved in these learning effects during the night and if we can experimentally enhance such effects.

"We want to assess how sleep disorders affect emotional and cognitive functioning, and what are the biological factors responsible for these effects."

A recent poll of 4,000 adults in the UK found only one in five sleep for eight hours a night.

Dr. Neil Stanley, sleep expert at Norfolk and Norwich University, said the findings highlight the importance of a full night's sleep.

"Sleep is not just a waste of time, it is a very active time and we need it for things like memory and learning," he said.

"During the day we acquire information, but at night we sort that information.

"People complain about sleep deprivation, but now with the 24/7 society and information overload we need our sleep more than ever."


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