Feline's four-legged walk reveals how memory works: study
Last Updated: Monday, August 20, 2007 | 5:04 PM ET
CBC News
Researchers found that cats' memories were much longer after stepping over an obstacle, rather than just seeing an object, says a study published Monday in the science journal Current Biology.
The scientists who led the study, David A. McVea and Keir G. Pearson, from the Department of Physiology at the University of Alberta, conducted a simple experiment to measure the felines' memories.
Audrey, a current resident of the Hemingway House in Key West, Fla.
(Wilfredo Lee/Associated Press)
They halted the cats' walking after their forelegs, but not hind legs, had cleared an obstacle. Then they distracted the animals with food, and lowered the obstacle into the walking surface. The next step revealed whether the cat remembered stepping over the "disappearing" obstacle.
The researchers then repeated the experiment to find out if the cats remembered what they saw, versus what they did. But this time they stopped the cats just before they made their first step.
McVea, told CBC News that this form of memory is equally vital to humans. "Although we use vision extensively to guide our walking, we don't look at our feet as we walk — we look three or four steps ahead and remember the terrain."
The scientists wanted to find out how long this type of memory lasts. "We found that the answer is a very long time. In fact, if you pause a cat after the front legs, but not the hind legs, have stepped over an object, it will remember the exact size and position of the object [without looking at it] for up to 10 minutes," he added.
McVea said this finding surprised the scientists, since short-term memories about objects usually fade away in under a minute.
"We began to think about what could make this memory special or different, and realized that one possibility was that the stepping of the forelegs over the object could engage a specialized part of the brain to preserve the memory of the object until the time when the hind legs had to step over the object," said McVea.
This research shows how we might remember things in our environment, even though we are constantly moving relative to those things.
"Think of all of the movements you make while you are in your office for example — swivelling in your chair, getting up to answer the door, reaching into the back of a desk. Your brain has to keep track of these movements and their impact on the position of objects around you," said McVea.
"We plan to use these sorts of experiments as simple ways to answer more complex questions, which will help us understand how animals and humans manage to remember the position of objects in their environment even as they move relative to them," he added.
