October 31, 2008

Asleep or Awake, Brain Functions the Same

FRIDAY, Oct. 31 (HealthDay News) -- The mind functions essentially the same when asleep as when awake, a new study shows.

The discovery, reported in the online journal Human Brain Mapping, could help scientists better understand the difference between a normal and an abnormal brain.

The finding is based on research by a team from Johns Hopkins University School of Medicine that studied the rapid eye movements (REM) in "dream" sleep of 11 healthy male and female participants in conjunction with special MRI images of their brain activity. It was found that during sleep, activity still occurs in areas of the brain that control sight, hearing, smell, touch, balance and body movements.

"This is the first time we have been able to detect brain activity associated with REM in areas that control senses other than sight," lead researcher Dr. Charles Hong, an assistant professor in the department of psychiatry and behavioral sciences at Johns Hopkins University School of Medicine, said in a school news release. "After comparing our data to other studies on awake people, we learned that our findings lend great support to the view that the waking brain functions in a similar way."

Such simultaneous study of major brain systems activated during REMs may be helpful in examining people with psychiatric diseases, movement disorders such as Parkinson's disease, Alzheimer's, and even in infant evaluations, Hong said. In awake studies, its required that subjects follow instructions and perform tasks to stimulate brain activity tasks that these groups might have difficulty completing.

"Head movements can create false data in MRI studies," he said, "while conveniently, REM sleep greatly reduces muscle tone, thus head movements."

Also, obtaining reliable results from awake participants required studying multiple subjects, while only six minutes of MRI data from a participant in the REM study produced "robust results," Hong said.

"We can also analyze changes over time within a single person with a psychiatric disease. Our method may make a powerful tool to study the development of the brain starting from birth," he said.

More information

The National Sleep Foundation has more about the importance of sleep.

-- Kevin McKeever
SOURCE: Johns Hopkins University School of Medicine, news release, Oct. 28, 2008
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