The curious case of a 70-year-old librarian who could describe anything she saw -- except animals -- has left two Johns Hopkins scientists with a deeper appreciation of the brain's astounding complexity.
She had a rare immune disorder in which antibodies attacked a small section in her temporal lobe -- a region toward the front of the brain, and off to one side. The illness left her mentally intact in all ways but one: She couldn't name animals or describe their physical appearance.
The woman was examined in the late 1980s by Dr. John Hart Jr. and Dr. Barry Gordon, specialists in the exploding field of cognitive neurology -- a science that explores what goes on inside the brain to make thinking, language, memory and "higher" functions such as spatial perception possible.
She subsequently died of a cancer that didn't directly afflict the brain but touched off an immune response that accounted for her peculiar language disorder. A report on her case appears in the latest issue of Nature, a prestigious British journal.
Most brain injuries, of course, leave people with broader deficits, such as trouble stringing words together on any subject.
But the scientists said they were intrigued by the case because it shows how intricately the brain must be organized if an injury can wipe out a function so narrow as the ability to name and describe animals.
The woman could name plants, foods and inanimate objects and describe them without hesitation. The scientists were impressed that when shown a trellis, not exactly your everyday object, she could correctly name it and describe its cross-hatched geometry.
But when shown a squirrel or a dog, she froze. She couldn't find the right name for either; nor could she describe their size or shape or furry coats.
Her deficit, involving only a tiny portion of her language skills, was amazingly narrow.
She could, for instance, discuss which animals made good pets and where the wild ones lived. And if shown illustrations of a green turtle and a gray one, she had no trouble pointing out which really exists in nature. To Dr. Hart's amazement, she could distinguish between a true dolphin, the marine mammal, and the edible fish sold in local markets.
And she knew how much the fish cost in the grocery store.
"Visually, she could recognize things appropriately," Dr. Hart said. "She could see them and recognize what they were. If she were to see one of these [animals] she would know how to react appropriately. But if she had to verbally describe what she knew about them, she would not know what to do."
Cases like the librarian's have caused neuroscientists to overhaul the conventional way of looking at the brain: one that envisions the organ as a neatly organized box with subdivisions handling such functions as language, memory and visual recognition.
"It provides a clue as to how incredibly complicated a system must be working," Dr. Gordon said.
"Who knows how much further we can break it down?" he said. "Intuitively, you wouldn't have guessed that things were separated like this, or that the brain would have bothered."
The doctors don't pretend to know exactly where the brain stores information about the things that make up the world, and how it finds language to describe them. But Dr. Gordon said it's possible that information about any one thing -- say, a dog -- isn't neatly organized in one area, but is scattered in small bits across a territory of the brain.
Tallness and shortness could be in one place, color in another, male and female in another, and pieces of anatomy scattered here and there. Recognizing the animal correctly, or organizing words to describe it, could mean pulling these bits together to make a composite picture.
For everything to work perfectly, the centers would have to be wired just so in a complex and endless circuitry. Cut one wire, and the brain might be profoundly impaired. Cut another, and it may lack one very specific function.
The librarian's case isn't the first to expand scientists' view of the brain's organization, but it could expand it yet another step.
Dr. Hart, who has been at this sort of work for seven years, said he has seen or heard of patients who can discuss non-living things but not living things, or describe anything but a facial expression.
What difference will such observations make? Scientists engaged in basic research can never be sure, but the Hopkins scientists said they can imagine this growing body of work could someday help doctors do a better job rehabilitating patients with severe brain injuries.
As doctors better understand how the brain is organized, they might help a stroke victim expand intact faculties to compensate for what's lost. Rehabilitation specialists already do this, but perhaps they could fine-tune their work.