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Here's a reason to tell your boss to "give you a break." As this ScienCentral News video explains, scientists working with rats say breaks from activities may help your memory.
Instant Replay for the Brain
"Crunch time" in our lives may mean no "break time." While some people feel like they don't have time between meetings, appointments, and chores throughout the day, researchers at the Massachusetts Institute of Technology say regular breaks are key to forming memories.
David Foster and his colleagues say that when rats take a break while exploring an unfamiliar area, their brains instantly replay the information they've just gathered.
As the rats run across a track, certain brain cells fire in a specific sequence. Each cell picks a "favorite place" on the track to go off, and a pattern emerges that is replicated every time the rat repeats the route. This "place cell" effect has been documented for more than 30 years.
These place cells lie in the hippocampus, which plays a key role in memory and navigation. Foster's research focuses on this part of the brain, which when damaged, he says, may leave a patient with memory problems similar to those seen in the popular 2000 movie "Memento."
But Foster and his colleagues were surprised to learn that when the rats took a break after running the track, the same exact place cells fired in reverse order. Replaying multiple times, these patterns were sped up, Foster says, almost 20 times faster.
"This immediately suggested some kind of learning mechanism occurring at times when the animal has just had an experience, but has in fact stopped," he says.
Foster theorizes that this repeated rewind gives other parts of the brain time to process and store the information. "Generally speaking, in the real world, rats exploring an environment are exposing themselves to dangers from predators," he says. "So if a rat can make the best use of his experience by replaying it in a safe place, it would presumably do so."
Previous research found a replay pattern occurring during sleep. But it was difficult to pin this pattern to learning, Foster says, because "sleep is possibly many hours from the experience, and in a different place." This overnight replay may be the brain's way of consolidating information for long-term memory.
He says that the replay mechanism may be part of how the brain packages information and sends it off to different parts of the brain. "It's still a little controversial," Foster says, "but the idea is that information may first be stored in the hippocampus, but then slowly integrated into long-term stores in different parts of the brain."
Brain cells in the rat instantly replay, in reverse order, when the rat takes a break.
According to Foster, this work can help explain previous research, which found that animals and people learn best when information isn't crammed together.
"Perhaps we don't take breaks seriously enough," Foster says. "Perhaps we're wrong to expect all learning to occur on the job. Perhaps an important part of learning in general, and in jobs and at school, is occurring during breaks."
Foster, who admits that he typically doesn't have enough time for coffee breaks, says that the rats, when taking a break, would be "eating, grooming ... basically at rest doing things that were natural to them. So it's really the idea of a mental break."
Foster's research was published in the March 30, 2006 edition of "Nature," and featured in the May 2006 edition of "Discover" Magazine. His research is funded by the National Institutes of Health and RIKEN, the Institute of Physical and Chemical Research in Japan.