Jay Ingram

“I once read that if the folds in the cerebral cortex were smoothed out it would cover a card table. That seemed quite unbelievable but it did make me wonder just how big the cortex would be if you ironed it out. I thought it might just about cover a family-sized pizza: not bad, but no card-table. I was astonished to realize that nobody seems to know the answer. A quick search yielded the following estimates for the smoothed out dimensions of the cerebral cortex of the human brain.An article in Bioscience in November 1987 by Julie Ann Miller claimed the cortex was a "quarter-metre square." That is napkin-sized, about ten inches by ten inches. Scientific American magazine in September 1992 upped the ante considerably with an estimated of 1 1/2 square metres; thats a square of brain forty inches on each side, getting close to the card-table estimate. A psychologist at the University of Toronto figured it would cover the floor of his living room (I haven't seen his living room), but the prize winning estimate so far is from the British magazine New Scientist's poster of the brain published in 1993 which claimed that the cerebral cortex, if flattened out, would cover a tennis court. How can there be such disagreement? How can so many experts not know how big the cortex is? I don't know, but I'm on the hunt for an expert who will say the cortex, when fully spread out, will cover a football field. A Canadian football field.”