World's worst memory, world's best memory

If we're talking best and worst, I'm probably somewhere near the top of the bottom third. I can remember plenty of unimportant things with ease: lines from old movies, commercial jingles, the geography of places I'll probably never go again. But when it comes to remembering everything my wife asked me to pick up at the grocery store, or my friends' birthdays or how to do calculus, my memory is like a leaky bucket. For instance, it's been bothering me recently that I can't for the life of me remember what I did on my eighteenth birthday. (It was certainly tame, so no substance-induced blackouts can explain this particular hole in my personal timeline.) Alas. What do you have trouble remembering?

To put all this in perspective, consider the cases of A.J. and E.P., who have quite possibly the best and worst memories in the world, respectively. (The following are excerpts from an Oct. 2007 National Geographic article.)

The best: A.J. There is a 41-year-old woman, an administrative assistant from California known in the medical literature only as "AJ," who remembers almost every day of her life since age 11. "My memory flows like a movie—nonstop and uncontrollable," says AJ. She remembers that at 12:34 p.m. on Sunday, August 3, 1986, a young man she had a crush on called her on the telephone. She remembers what happened on Murphy Brown on December 12, 1988. And she remembers that on March 28, 1992, she had lunch with her father at the Beverly Hills Hotel. She remembers world events and trips to the grocery store, the weather and her emotions. Virtually every day is there. She's not easily stumped. There have been a handful of people over the years with uncommonly good memories. Kim Peek, the 56-year-old savant who inspired the movie Rain Man, is said to have memorized nearly 12,000 books (he reads a page in 8 to 10 seconds). "S," a Russian journalist studied for three decades by the Russian neuropsychologist Alexander Luria, could remember impossibly long strings of words, numbers, and nonsense syllables years after he'd first heard them. But AJ is unique. Her extraordinary memory is not for facts or figures, but for her own life.

The worst: E.P.
EP is six-foot-two (1.9 meters), with perfectly parted white hair and unusually long ears. He's personable, friendly, gracious. He laughs a lot. He seems at first like your average genial grandfather. But 15 years ago, the herpes simplex virus chewed its way through his brain, coring it like an apple. By the time the virus had run its course, two walnut-size chunks of brain matter in the medial temporal lobes had disappeared, and with them most of EP's memory.

The virus struck with freakish precision. The medial temporal lobes—there's one on each side of the brain—include an arch-shaped structure called the hippocampus and several adjacent regions that together perform the magical feat of turning our perceptions into long-term memories. The memories aren't actually stored in the hippocampus—they reside elsewhere, in the brain's corrugated outer layers, the neocortex—but the hippocampal area is the part of the brain that makes them stick. EP's hippocampus was destroyed, and without it he is like a camcorder without a working tape head. He sees, but he doesn't record.

EP wears a metal medical alert bracelet around his left wrist. Even though it's obvious what it's for, I ask him anyway. He turns his wrist over and casually reads it. "Hmm. It says memory loss."

EP doesn't even remember that he has a memory problem. That is something he discovers anew every moment. And since he forgets that he always forgets, every lost thought seems like just a casual slip—an annoyance and nothing more—the same way it would to you or me. Ever since his sickness, space for EP has existed only as far as he can see it. His social universe is only as large as the people in the room. He lives under a narrow spotlight, surrounded by darkness.