- German scientists say they have demonstrated for the
first time that our sleeping brains continue working on problems that baffle
us during the day, and the right answer may come more easily after 8 hours
- The German study is considered to be the first hard evidence
supporting the common sense notion that creativity and problem solving
appear to be directly linked to adequate sleep, scientists say. Other researchers
who did not contribute to the experiment say it provides a valuable reminder
for overtired workers and students that sleep is often the best medicine.
- Previous studies have shown that 70 million Americans
are sleep-deprived, contributing to increased accidents, worsening health
and lower test scores. But the new German experiment takes the subject
a step further to show how sleep can help to turn yesterday's problem into
- "A single study never settles an issue once and
for all, but I would say this study does advance the field significantly,"
said Dr. Carl E. Hunt, director of the National Center on Sleep Disorders
Research at the National Institutes of Health.
- "It's going to have potentially important results
for children for school performance and for adults for work performance,"
- Scientists at the University of Luebeck in Germany found
that volunteers taking a simple math test were three times more likely
than sleep-deprived participants to figure out a hidden rule for converting
the numbers into the right answer if they had eight hours of sleep. The
results appear in Thursday's issue of the journal Nature.
- The study involved 106 people divided into five separate
groups of equal numbers of men and women ages 18 to 32. One group slept,
another stayed awake all night, and a third stayed awake all day for eight-hour
periods before testing following training in the main experiment. Two other
groups were used in a supplemental experiment.
- The study participants performed a "number reduction
task" according to two rules that allowed them to transform strings
of eight digits into a new string that fit the rules. A third rule was
hidden in the pattern, and researchers monitored the test subjects continuously
to see when they figure out the third rule.
- The group that got eight hours of sleep before tackling
the problem was nearly three times more likely to figure out the rule than
the group that stayed awake at night.
- Jan Born, who led the study, said the results support
biochemical studies of the brain that indicate memories are restructured
before they are stored. Creativity also appears to be enhanced in the process,
- "This restructuring might be occurring in such a
way that the problem is easier to solve," Born said.
- Born said the exact process in the sleeping brain for
sharpening these abilities remains unclear. The changes leading to creativity
or problem-solving insight occur during "slow wave" or deep sleep
that typically occurs in the first four hours of the sleep cycle, he said.
- The results also may explain the memory problems associated
with aging because older people typically have trouble getting enough sleep,
especially the kind of deep sleep needed to process memories, Born said.
- "Even gradual decreases in the total time for slow
wave sleep and deep sleep is correlated to a kind of decrease in memory
function, and in turn to a decrease in the ability to recognize hidden
structures or the awareness of such things," Born said.
- Other researchers said they have long suspected that
sleep helps to consolidate memories and sharpen thoughts. But until now
it had been difficult to design an experiment that would test how it improves
- History is dotted with incidents where artists and scientists
have awakened to make their most notable contributions after long periods
of frustration. For example, that's how Russian chemist Dmitri Mendeleev
established the periodic table of elements and British poet Samuel Taylor
Coleridge wrote his epic "Kubla Khan."
- Born and his team "have applied a clever test that
allows them to determine exactly when insight occurs," wrote Pierre
Maquet and Perrine Ruby at the University of Liege in a commentary on the
research, also published in Nature.
- Maquet and Ruby both say the study should be considered
a warning to schools, employers and government agencies that sleep makes
a huge difference in mental performance.
- The results "give us good reason to fully respect
our periods of sleep - especially given the current trend to recklessly
curtail them," they said.
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