People who tend to remember their dreams also respond more
strongly than others to hearing their name when they're awake, new research
suggests.
Everyone dreams during sleep, but not everyone recalls the
mental escapade the next day, and scientists aren't sure why some people
remember more than others.
To find out, researchers used electroencephalography to
record the electrical activity in the brains of 36 people while the
participants listened to background tunes, and occasionally heard their own
first name. The brain measurements were taken during wakefulness and sleep.
Half of the participants were called high recallers, because they reported remembering
their dreams almost every day, whereas the other half, low recallers,
said they only remembered their dreams once or twice a month.
When asleep, both groups showed similar changes in brain
activity in response to hearing their names, which were played quietly enough
not to wake them.
However, when awake, high recallers showed a more sustained
decrease in a brain
wave called the alpha wave when they heard their names, compared with
the low recallers.
"It was quite surprising to see a difference between
the groups during wakefulness," said study researcher Perrine Ruby,
neuroscientist at Lyon Neuroscience Research Center in France.
The difference could reflect variations in the brains of
high and low recallers that could have a role in how they dream, too, Ruby
said.
Who remembers their dreams
A well-established theory suggests that a decrease in the
alpha wave is a sign that brain regions are being inhibited from responding to
outside stimuli. Studies show that when people hear a sudden sound or open
their eyes, and more brain regions become active, the alpha wave is reduced.
In the study, as predicted, both groups showed a decrease in
the alpha wave when they heard their names while awake. But high recallers
showed a more prolonged decrease, which may be a sign their brains became more
widely activated when they heard their names.
In other words, high recallers may engage more brain regions
when processing
sounds while awake, compared with low recallers, the researchers said.
While people are asleep, the alpha wave behaves in the opposite way —it
increases when a sudden sound is heard. Scientists aren't certain why this
happens, but one idea is that it protects the brain from being interrupted by
sounds during sleep, Ruby said.
Indeed, the study participants showed an increase in the
alpha wave in response to sounds during sleep, and there was no difference between
the groups.
One possibility to explain the lack of difference, the
researchers said, could be that perhaps high recallers had a larger increase in
alpha waves, but it was so high that they woke up.
Time spent awake, during the night
The researchers saw that high recallers awoke
more frequently during the night. They were awake, on average, for 30
minutes during the night, whereas low recallers were awake for 14 minutes.
However, Ruby said "both figures are in the normal range, it’s not that
there’s something wrong with either group."
Altogether, the results suggest the brain of high recallers
may be more reactive to stimuli such as sounds, which could make them wake up
more easily. It is more likely a person would remember their dreams if they are
awakened immediately after one, Ruby said.
However, waking up at night can account for only a part of
the differences people show in remembering
dreams. "There's still much more to understand," she said.
Don't forget to follow my facebook fanpage and instagram - ile.ustimih
Credits: https://www.livescience.com/38856-why-people-recall-dreams.html
The study is published online today (Aug. 13) in the journal
Frontiers in Psychology.
Email Bahar
Gholipour. Follow LiveScience @livescience, Facebook & Google+.
Original article on LiveScience.
Follow Us
Were this world an endless plain, and by sailing eastward we could for ever reach new distances