People ask me all the time why they blank on names. One scientist, Marilyn Albert, the director of cognitive neuroscience at Johns Hopkins, told me that the failure to retrieve people’s names is so common that when her researchers select midlife or older subjects to participate in investigations of memory, they don’t count difficulty with names as an indication of emerging pathology. It’s just…well, normal.

That doesn’t make it a shred less irritating when you see your boss’s wife approaching at a rapid clip, and for the life of you, you can’t think of her name. Your eyes roll back in your head as you struggle for a hint. It’s Mary-something, but what? Anne? Lou? Jane? Beth? “Mary-hmmmm” you murmur as you greet her, hoping she doesn’t notice. (She does.) The rest of her name shows up in the middle of the night, wrenching you out of your dreams. It was in there, obviously—but where?

The trouble’s not new—Roman aristocrats always traveled with an alert slave called a “nomenclatur,” whose duty it was to supply his master with the names of acquaintances as they were encountered. I understand that while raising funds for campaigns, many of today’s political figures rely on a backfield of aids whose job it is to stand by and produce names as required, subtly thumbing the contact databases in their Blackberries. Great idea, but for most of us, not feasible—we’re working without a net.

After a great deal of research, I’ve concluded that the problem with modern names is that they fail to provide helpful clues that would allow us to fully encode the incoming data. The name “Ann” is lovely, but it does not come with recognizable characteristics—nothing about your neighbor is particularly Ann-like. There were some periods in history when it was de rigueur to insert a bunch of identifying information into a name. You were Jacob, son of Isaac and Rebecca, or Pocahontas, whose name translates as “always playful,” or, in early feudal Europe, The Lord of Something Really Big. When surnames came along—so the census takers for the Domesday Book could keep track—identifying names were handed out based on occupations—Smith, Baker, Weaver, Carpenter, Taylor, Brewer, Mason—or geography—Brook, Dale, Hill—or physical characteristics—Stout, Moody, Wise, Rich, Poor, Strong.

It’s rare to find anyone today whose given name or surname name reflects his or her demeanor, physique, hometown or profession. When you find one—the aptly named dentist, Dr. Needleman, comes to mind—you don’t have any trouble looking him up your address book. Given names or nicknames that allude to physical or psychological traits used to be good for a fond chuckle—I knew a hefty bartender everyone called Chubby, someone’s aunt who was actually named Pussy, my mother’s lively English friend who has struggled for years with the old-fashioned name Gay, and the trash collector of my childhood, who answered to Stinky. Understandably, these names are out of fashion, deemed politically incorrect. Still, I’d just love it if my electrician were named Sparky. I might not have to go through my entire database, searching for likely names, before I phoned him.

Although I do not know the name of a single human being in our local dog park, I can reliably greet most of the canine regulars. So many are endowed with names that mirror their physical traits or provenance. There’s Fidel, the Havanese, whose handle reflects his Cuban roots. There’s Einstein, a charmingly disheveled Schnauzer, and Bounce, a Jack Russell mix who came from the pound equipped with heavy-duty rocket thrusters. There’s Speed Bump, a Bassett-Beagle cross, and of course my dog Radar, who never leaves my side. My other pet, Rosie, a shepherd mutt, is more obscurely named, but I rescued her from the Santa Rosa Animal Shelter, a fact that allows people who make the connection to recall her name with ease.

Some well-known memory trainers (the kind who write books that promise that you can learn the names of thirty people at your next cocktail party) suggest that whenever you meet someone new, you ought to make a quick survey of his or her physical appearance—an attractive scarf on a redhead named Rose Sharf, for instance—and then try to link specific characteristics to the person’s name. Unlike dogs, people change things up, so this technique is loaded with ways to go astray. While you’re busily creating this image, you’re likely to miss the next six things that are happening, including introductions to several other people. It’s a fair bet that Rose won’t be wearing that pink scarf the next time you see her, or even twenty minutes later, if the day is warm. In fact, the next time you and Rose rendezvous, she may have decided that with her coloring, the russet tones are just too harsh—and gone blond.

What can you do? Before you go to an event where you are likely to see people you feel you should know, but haven’t encountered recently or frequently, review the list of names of those who will probably attend. Use a school or club directory, or check back through related correspondence. Email announcements or invitations, or anything that comes through the party invitation website Evite can be great memory joggers: Often the list of everyone who is invited is right there, in the “To” box, awaiting your inspection. Ignore it at your peril.

For more about how to stop forgetting proper nouns and other words, see Chapter Four in Carved In Sand, “Blocking, Blanking and Begging For Mercy.”

I don’t mean to be unsympathetic, but I have to believe that from the day he signed his contract with the New England Patriots, middle linebacker Ted Johnson knew he had chosen a career path that mandated headlong collisions with speeding flesh dressed in helmets and shoulder pads. The same could be said for other professional athletes whose brains have made the news in the last year—the late Andre Waters, formerly of the Philadelphia Eagles, and Bob Brudzinski, who played 13 seasons with the Miami Dolphins and the Los Angeles Rams. They took some hard knocks—okay, a lot of them—and they've paid a grave price.

But what about the rest of us? You don’t have to be a pro football player to put your head in jeopardy. According to the National Center for Injury Prevention and Control, at least 1.1 million people each year sustain mild traumatic brain injuries. No doubt, that number is set too low: Most people who sustain such "minor" injuries do not go to the emergency room or a doctor’s office. They go home and lie down on the sofa.

The assumption has always been that our skulls—which seem pretty hard—function as protective shells. In fact, what’s inside—a brain with the consistency of gently scrambled eggs—is very vulnerable. Throughout our lives, the injuries that we experience accumulate in a way that can result in noticeable cognitive deficits. It is impossible to say how many middle-aged adults who presume they are suffering from age-related memory impairment, or maybe adult ADHD, are actually feeling the consequences of a series of earlier head injuries.

Until a decade ago, scientists regarded mild traumatic brain injury—where there is no loss of consciousness or evident structural damage—as inconsequential. You were expected to recover quickly and entirely from such an accident, and anyone who presented symptoms after a month or two was considered to be "malingering," probably in the interest in settling a large lawsuit.

Only in the last several years have experts begun to understand what happens when your brain meets the bony protuberances behind the forehead, surrounding the prefrontal cortex. Forget about being knocked unconscious: Most mildly concussed individuals remain wide awake, working their way through a variety of symptoms, from feeling dazed and confused to seeing stars. Often, there's a touch of amnesia involved—they're not sure what happened to them, before, during or immediately after the impact.

As used here, the word "impact" requires some clarification. You can have a concussion when your head encounters an immovable object—for instance, the windshield during an auto accident. But the collision can also occur internally. Slam on the brakes when you’re driving twenty miles an hour, secure in your seatbelt and guess what: Your car screeches to a stop, but your brain keeps going forward. In fact, this three-pound bolus of fat smacks your bony prefrontal protuberances at your previous pace, and then begins to imitate a Superball, ricocheting all over the place inside your skull.

Car accidents are responsible for the bulk of mild traumatic brain injuries, but increasingly, we're finding other ways to mess up our heads. Sports injuries account for more than 20 percent of the mild traumatic brain injuries each year. You can have a closetful of helmets—biking, riding, rafting, hockey, lacrosse, skiing, even river rafting—and while they'll do wonders to preserve the exterior of your skull, they don’t help much with what is inside. You can wallop your head executing perfectly innocent maneuvers: one Los Angeles woman I know walked headlong into a low hanging branch of a sturdy oak tree while reading a catalog from an art gallery she'd just visited, and knocked herself flat. Some weeks later, she was cleaning up a Coke that had exploded in the little refrigerator under a granite counter in her family room. She stood up suddenly—and wham, she was down again.

Right about the time that you’re catching your breath, impressed with your evasive driving skills and your anti-lock brakes, the cascade of damage inside your head begins. Researchers are still trying to understand exactly what happens when these injuries occur. One common hypothesis is that arteries in the brain constrict, make it impossible to deliver sufficient glucose, but that is only part of the story. When the brain makes contact with the sharp bones inside the skull, small blood vessels may rupture, releasing blood into the cranium, which, unlike other parts of the body, cannot expand to encompass it. The brain is uncomfortably squeezed for space. "Second impact syndrome," as too often experienced by Mr. Johnson and other athletes, is especially dangerous because that second hit increases that intracranial pressure. Often, as the brain does its Superball routine, microscopic tears develop in the myelin sheath surrounding the nerve fibers that transmit information from one part of the brain to another. These torn nerve fibers, called axons, develop scar tissue, which will eventually affect the speed and efficiency of synaptic impulses.

Typically, we put our mild head injuries behind us, heading back to work or school. Weeks or months later, we’re befuddled when we find that we’re suffering from inexplicable impairment—typically, problems with working memory and executive function, cognitive faculties regulated mostly by the prefrontal cortex. The real damage shows up long after the injury has been forgotten, as ruptured axons, rife with scar tissue, begin to die, reducing the capacity to process information. For many people who experience mild traumatic head injuries, the senior moments start coming fast and furiously, no matter what age they are.

It’s becoming evident that even mild traumatic head injuries (defined as injuries where you do not lose consciousness) may lead to an increased risk of Alzheimer's disease, particularly if you are a carrier of a genetic variant called the ApoE-4 allele. So far, most of the research (performed on rats at the University of Pennsylvania's Head Injury Center) suggests that repetitive mild brain trauma accelerates the emergence of Alzheimer's disease. No one has nailed down how this happens, but the theory is that the axons sheared in the Superball routine release a sudden bounty of lipids, which attract hordes of greedy free radicals, which in turn step up oxidative damage to the brain. It's been hypothesized that excessive oxidation makes neurons more vulnerable to the effects of amyloid proteins, and may also escalate the development of amyloid plaques, which slowly strangle nerve cells.

In a recent edition of the New York Times, journalist Alan Schwarz wrote an excellent piece about how head injuries are affecting 1.2 million teenagers who play high school football. As I said earlier, I'm not overwhelmed with sympathy for pro players, but my heart goes out to these high school kids. They're suffering from a common adolescent misconception: Their fervent belief in their own immortality. They keep their head injuries secret, conscientiously reporting, after they've been hit, that they feel fine—not the slightest hint of headache, no nausea or disorientation, in order to remain in the game. Pre-season, team members submit to baseline neuropsych evaluations, but they've figured out how to work 'em. Intentionally, they perform poorly—so that if they're hit, and experience cognitive sequellae, there won’t appear to be a change in their performance. Very tricky—but in large numbers, they make themselves vulnerable to second-impact syndrome.

These high school players are also suffering from lack of information—in his article, Schwarz noted that most players "did not quite know what a concussion was," and still believed that to have suffered one, you had to fall unconscious. Teenagers, observes Schwarz, are "more susceptible to immediate harm from such injuries because, studies show, their brain tissue is less developed than adults’ and more easily damaged. High school players also receive less capable medical care, or none at all." According to Schwarz, many parents and coaches exacerbate the situation by encouraging players who have taken a hit to get back in the game. One source reported that "he’d seen coaches...berate and ostracize players who complained of concussive symptoms." Parents have been known to "shop a doc," who is willing to give a concussed teen player a clean bill of health, another coach told Schwarz, so that their child can return to the game.

At least 50 high school or younger football players in more than 20 states since 1997 have been killed or have sustained serious head injuries on the field, according to the New York Times' research. The dedicated and sometimes obsessively competitive people who coach children's sports ought to acknowledge that they are not capable, at a glance, of assessing whether a young athlete might have suffered a concussion. No matter how good a player is, the only place for him or her after a bell-ringing incident (even a suspected one) is on the bench for a couple of weeks, to avoid the vastly increased danger of second-impact syndrome. Parents should demand this, but unaware of the consequences, most do not. They want to see Junior back in the game. Maybe, if he gets a little more play, he can make it to the NFL.

I don’t usually send jokes over the Internet (or even tell them very often), mostly because I can’t remember them. This howler arrived last week from my cousin Jodi—who received it from a friend whose father was in the pharmaceutical business. I just had to pass it along. Take everything between the quotation marks with a grain of salt, please…

"In the field of pharmacology, all drugs have two names, a trade name and a generic name. For example, the popular drug known by the trade name of Tylenol also has a generic name of acetaminophen. Aleve is also called naproxen. Amoxil’s generic is amoxicillin and Advil is called ibuprofen.

The FDA has been looking for a generic name for Viagra. After careful consideration by a team of government experts, it recently announced that it has settled on the generic name of Mycoxafloppin. Also considered were Mycoxafailin, Mydixadrupin, Mydixarizin, Dixafix, and of course, Ibepokin.

 Pfizer Corp., which manufactures Viagra and is searching for new formulations that will allow the company to maintain its market share, announced today that Viagra will soon be available in liquid form, and will be marketed by Pepsi Cola as a power beverage suitable for use as a mixer. It will now be possible for a man to literally pour himself a stiff one. Obviously we can no longer call this a soft drink, and it gives new meaning to the names of "cocktails", "highballs" and just a good old-fashioned "stiff drink." Pepsi will market the new concoction by the name of 'MOUNT & DO'."

Guffaw, definitely. But a thought for the day:

Right now, more money is being spent on developing and marketing erectile dysfunction drugs ($2 billion in 2006) than the federal government is committing to Alzheimer's research—around $1 billion. You know the statistics all too well: Five million Americans have Alzheimer's disease, including 500,000 people under the age of 65. Earlier this year, the Alzheimer's Association estimated that someone in America is diagnosed with Alzheimer’s every 72 seconds. It's the seventh leading cause of death in the United States and nearly as prevalent in Japan and Europe. The direct and indirect costs of Alzheimer's in the U.S. amount to $148 billion annually. In 2005, state and federal Medicaid spending for nursing home and home care for people with Alzheimer's and other dementias was estimated at $21 billion; that number is expected to increase to $27 billion by 2015. If the disease proceeds unimpeded, by 2030, the number of people with Alzheimer's is projected to increase to 7.7 million. When you consider that by 2030, almost one in five Americans will be over sixty-five, it's apparent that we face a health burden that will swamp us.

If you don’t want to end your life this way, you need to let Washington know about it. How fast we can get this disease under control depends largely on how much money we can throw at it. New tools that will permit early diagnosis and treatment are on the horizon, including biomarkers that assess protein levels in urine, cerebrospinal fluid and blood. There are currently eight drugs in Phase III clinical trials for Alzheimer's. One primary prevention trial costs more than $30 million and takes five to ten years. So write to your representatives in Congress and tell them you want a treatment sooner, rather than later. Even better, sign up at your local university Alzheimer's center to participate in a research—they need normal subjects as well as subjects who may be in the early stages of dementia. For more information about participating in clinical trials, visit the Alzheimer's Association website. For a list of universities with active Alzheimer's research programs, go to this list on my website. For more on the subject of Alzheimer's research, see Chapters 17 and 18 of Carved in Sand: When Attention Fails and Memory Fades in Midlife. You’ll be doing yourself—and the rest of us—a big favor.