These patients were a puzzle because although they still lived alone, successfully, in the city, they really should not have been able to do so. On standard psychological tests they performed rather dismally. They should have been unable to cope with the demands of daily life. What was going on?

A sequence of visits to their home environments provided the answer. These home environments, it transpired, were wonderfully calibrated to support and scaffold these biological brains. The homes were stuffed full of cognitive props, tools, and aids. Examples included message centers where they stored notes about what to do and when; photos of family and friends complete with indications of names and relationships; labels and pictures on doors; "memory books" to record new events, meetings, and plans; and "open-storage" strategies in which crucial items (pots, pans, checkbooks) are always kept in plain view, not locked away in drawers.

Before you allow this image of intensive scaffolding to simply confirm your opinion of these patients as hopelessly cognitively compromised, try to imagine a world in which normal human brains are somewhat Alzheimic. Imagine that in this world we had gradually evolved a society in which the kinds of scaffolding found in the St. Louis home environments were the norm. And then reflect that, in a certain sense, this is exactly what we have done. Our own pens, paper, notebooks, diaries, and alarm clocks complement our brute biological profiles in much the same kind of way. Yet we never say of the artist, or poet, or scientist, "Oh, poor soul -- she is not really responsible for that painting/theory/poem; for don't you see how she had to rely on pen, paper, and sketches to offset the inadequacies of her own brain?"