Sandy Bem, a Cornell psychology professor one month shy of her 65th birthday, was alone in her bedroom one night in May 2009, watching an HBO documentary called “The Alzheimer’s Project.” For two years, she had been experiencing what she called “cognitive oddities”: forgetting the names of things or confusing words that sounded similar. She once complained about a “blizzard” on her foot, when she meant a blister; she brought home a bag of plums and, standing in her kitchen, pulled one out and said to a friend: “Is this a plum? I can’t quite seem to fully know.”
Sandy was a small woman, just 4-foot-9 and 94 pounds, with an androgynous-pixie look: cropped hair, glasses and a wardrobe that skewed toward jeans and comfortable sweaters she knit herself in the 1990s. As she watched the documentary, her pulse thrumming in her ears, a woman on screen took a memory test. Sandy decided to take it along with her. Listen to three words, the examiner said, write a sentence of your choice and then try to remember the three words. Sandy heard the three words: “apple,” “table,” “penny.” She wrote a brief sentence: “I was born in Pittsburgh.” She said aloud the words she could remember: “apple,” “penny” . . . . The simplest of memory tests, and she had failed.