Dec. 22, 2005
Courtesy Science
and World Science staff
Humans may dredge up memories by recreating the pattern of brain activity that occurred when a remembered event first happened, some scientists believe. The psychologist Endel Tulving has called the process “mental time travel.”
Now, researchers have found that we do much of this time traveling before the memory actually “resurfaces” to parts of the brain in which we can talk about it.
Sean Polyn of Pennsylvania State University in University Park, Penn., and colleagues analyzed brain scans from people who looked at pictures of celebrities such as Bruce Lee and Halle Berry, famous places like the Taj Mahal and everyday objects such as tweezers. The participants were later asked to recall as many of the photos as possible.
The researchers found that brain activity patterns associated with each picture reinstated themselves seconds before the people talked about them.
The scientists were even able to do a little “mind-reading,” they added, by guessing whether the people were going to remember a celebrity, place or object from the reestablished brain pattern.
The findings are published in the Dec. 23 edition of the research journal Science. The authors wrote that their technique is “...a powerful new tool that researchers can use to test and refine theories of how people mine the recesses of the past.”
The mind-reading capabilities of brain scanning technologies have been improving, scientists say. A study published last April found that when people were shown simple patterns of stripes tilted in different directions, a computer could analyze their brain activity to figure out which pattern they were looking at.
