Extra sleep boost brain power: study

British and American studies show that even getting an extra hour of sleep help improve learning capacity, and memory power.

A small boost to our nightly slumber can improve memory and increase learning capacity, according to Professor Matthew Walker, director of the Centre for Human Sleep Science at Berkeley California.

Prof Walker, who recently published his book Why We Sleep, drawing on 20 years of research and findings from his laboratory, said: "Just 60-90 minutes of additional sleep boosts the learning capacity of the brain, significantly increasing memory retention of facts and preventing forgetting."

In a study published six years ago in Current Biology, Prof Walker, along with a team of other researchers, demonstrated that during a demanding memorising task, test subjects who were allowed extra nap time performed better than those who did not.

They found the brain's ability to learn was linked to sleep spindles - which are fast pulses of electricity generated during REM (rapid eye movement) sleep, which accounts for 25% of total sleep time in adult humans.

Spindle-rich sleep, which is said to occur in the second half of the night, helps with the brain's ability to create new memories by "clearing a path to learning".

But it's not just about improved brain power.

Experiments conducted in 2013 by the Surrey Sleep Centre and the BBC showed a link between an extra hour in bed and genetic expression that helps protect against illnesses such as diabetes, cancer, inflammation and stress.

Scientists at the centre in Guildford divided the participants into two groups. During the first week, one group slept for six-and-a-half hours a night while the other had seven-and-a-half hours of shut-eye. The volunteers then switched their sleep patterns in the second week.

The researchers found that those who had less sleep struggled with mental agility tasks.

Blood tests revealed that genes associated with processes such as inflammation, immune response and response to stress became more active for those who had less sleep.

A 2008 study published in the Journal of the American Medical Association showed that adults who slept for seven hours a night had a lower chance of having calcium deposits in their arteries than adults who had only six hours of sleep.