Brain Uses Past to Peer Into Future
Wednesday, January 3, 2007; 12:00 AM
WEDNESDAY, Jan. 3 (HealthDay News) -- Your past may be key to your dreams for the future, new research suggests.
In experiments using high-tech brain imaging, scientists have found that neurological memory centers are highly active whenever people envision upcoming events.
"It shows us that memory is just as important to imagining the future as it is to remembering the past," said lead researcher Karl Szpunar, a graduate student in the department of psychology at Washington University, in St. Louis.
Besides furthering understanding of the brain, the findings might help research into amnesia and depression, Szpunar added.
His team published its findings in this week's issue of theProceedings of the National Academy of Sciences.
According to Szpunar, there's been a century of intensive research on how the brain recalls the past but precious little on how it projects into the future -- something only humans are thought able to do. "No one had really looked at how it is that we form these vivid mental images of events that have not yet occurred," he said.
To find out more, Szpunar's team had 21 young adults undergo real-time functional MRI (fMRI), which tracks ongoing activity in the brain. Participants were asked to ponder a variety of personal scenarios, either from the past or the imagined future.
One surprise emerged early. "Until now, people had really thought that thinking about the future is a process that occurs solely in the brain's frontal lobe," Szpunar said. However, the fMRI data showed that a variety of brain areas were activated when subjects daydreamed about the future -- in the cortex's frontal and posterior lobes, in the cerebellum, and elsewhere.
Most important, neurological memory centers leapt into activity whether participants were recalling the past or envisaging their future, the researchers found.
The exact role of memory in the latter case isn't clear, but Szpunar has a theory.
"In order to form these vivid mental images of the future, what we are doing is relying on our memories," he said. "For example, if I am imagining myself at the grocery store, the mental images that I have stored in my head are of thelocalgrocery store -- it's not just coming out of thin air. I'm retrieving it from my memory and using it in this novel way."
One expert said the theory makes sense based on what scientists know about the brain.