I Think, Therefore I'm an Old Polecat

Virginia Postrel links to a University of Rochester study on ferret brain activity. (What's the difference between a ferret and a polecat? "Taxonomically speaking -- there is no difference. Both are currently classified as Mustela putorius.")

There's an old myth that we only use 10 percent of our brains, but researchers at the University of Rochester have found in reality that roughly 80 percent of our cognitive power may be cranking away on tasks completely unknown to us. Curiously, this clandestine activity does not exist in the youngest brains, leading scientists to believe that the mysterious goings-on that absorb the majority of our minds are dedicated to subconsciously reprocessing our initial thoughts and experiences. The research, which has possible profound implications for our very basis of understanding reality, appears in this week's issue of the journal Nature.

"We found neural activity that frankly surprised us," says Michael Weliky, associate professor of brain and cognitive sciences at the University of Rochester. "Adult ferrets had neural patterns in their visual cortex that correlated very well with images they viewed, but that correlation didn't exist at all in very young ferrets, suggesting the very basis of comprehending vision may be a very different task for young brains versus old brains."

A second surprise was in store for Weliky. Placing the ferrets in a darkened room revealed that older ferrets' brains were still humming along at 80 percent as if they were processing visual information. Since this activity was absent in the youngsters, Weliky and his colleagues were left to wonder: What is the visual cortex so busy processing when there's no image to process?

Initially, Weliky's research was aimed at studying whether visual processing bore any resemblance to the way real-world images appear. This finding may help lead to a better understanding of how neurons decode our world and how our perception of reality is shaped.