An Alchemy of Mind: The Marvel and Mystery of the Brain

Chapter 13: What Is a Memory?

Like tiny islands on the horizon, they can vanish in rough seas. Even in calm weather, their coral gradually erodes, pickled by salt and heat. Yet they form the shoals of a life. Some offer safe lagoons and murmuring trees. Others crawl with pirates and reptiles. Together, they connect a self with the mainland and society. Plot their trail and a mercurial past becomes visible.

Memories feel geological in their repose, solid and true, the bedrock of consciousness. They may include knowing that it's hard to lead a cow down steps, or how the indri-indri of Madagascar got its name, or the time you accidentally grabbed a strange man's hand in a crowd (thinking it was your friend's), or how you felt hitting a home run in Little League, or your first car (a used VW that rattled like an old dinette set), or a grisly murder you just read about that made you rethink capital punishment, or an unconscious detailed operating guide to the body that manages each cell's tiny factory.

Memories inform our actions, keep us company, and give us our noisy, ever-chattering sense of self. Because we're moody giants, every day we subtly revise who we think we are. Part of the android's tragedy in the Ridley Scott film Blade Runner is that he possesses a long, self-defining chain of memories. Though ruthless and lacking empathy, and technically not a person, he can remember. Played by Rutger Hauer, he contains a self who witnessed marvels on Earth and Mars and fears losing his unique mental jazz in death.

Without memories we wouldn't know who we are, how we once were, who we'd like to be in the memorable future. We are the sum of our memories. They provide a continuous private sense of one's self. Change your memory and you change your identity. Then shouldn't we try to bank good memories, ones that will define us as we wish to be? I'm surprised by how many people do just that. Even tour companies advertise: "Bring home wonderful memories." Here we are, a happy family taking a Disney cruise, documented on film. But memory isn't like a camcorder, computer, or storage bin. It's more restless, more creative, and it's not one of anything. Each memory is a plural event, an ensemble of synchronized neurons, some side by side, others relatively far apart.

Everyone will always remember where they were on September 11, 2001, or when men first walked on the moon. Shared memories bind us to loved ones, neighbors, our contemporaries. The sort of memory I'm talking about now isn't essential for survival, and yet it pleases us, it enriches everyday life. So couples relive romantic memories, families watch home movies, and friends "catch up" with each other, as if they've lagged behind on a trail. Sifting memory for saliences to report, they reveal how vital pieces of their identity have changed. Aging, we tailor memories to fit our evolving silhouette, and as life's vocabulary changes, memories change to fathom the new order. Lose your memory, and you may drift in an alien world.

Mind you, memories are kidnappable. Radio, television, and the print media purvey shared national memories that can usurp a personal past. All the why's can change. A world of artificial memory, as the British neuroscientist Steven Rose points out, "means that whereas all living species have a past, only humans have a history." And, at that, it tends to be the history of the well to do. Thanks to the compound eye of the media, millions of people are spoon-fed the same images, slogans, history, myths. What happens to individual memories then? Some rebels refuse that programming, or they prefer their own group's ideologies. But most people do adopt values and interpretations of events from the media, their neighbors, or a favorite tyrant. Official history changes with each era's values, which can sometimes be perverse, what Jung described as a large-scale psychic ailment. "An epoch," he said, in Modern Man in Search of a Soul, "is like an individual; it has its own limitations of conscious outlook, and therefore requires a compensatory adjustment...that which everyone blindly craves and expects -- whether this attainment results in good or evil, the healing of an epoch or its destruction." Still, though no one is an island, most are peninsulas. Our lives wouldn't make sense without personal memories pinned like butterflies against the velvet backdrop of social history.

Scientists sometimes talk about "flashbulb" memories so intense they instantly brand the mind. Photography provided something different: push-button memories that revolutionized our sense of self and family, which we often remember in eye-gulps, as snapshots. Walt Whitman, in his journals, jotted down the name of each of his lovers and sometimes what they did for a living, as though he might one day forget his moments of loving and being loved. But I think he would have preferred photographs of those dear ones to help recall the liquid mosaic of each face.

Picture yourself younger, and what image forms? Most likely it's a static image, a snapshot someone took. Memories can pile up and become mind clutter; it's easier to store them in albums. We remember our poses. Each photograph is a magic lamp rubbed by the mind. When we're in the mood, we can savor a photograph while sensations burst free. Right now, for example, I'm holding a photograph of a pungent king penguin rookery in Antarctica, and I remember the noisy clamor like a combination of harmonica and oncoming train. I remember how inhaling glacial cold felt like pulling a scarf through my nostrils. I remember that, in such thin air, glare became a color.

Whenever we look at a photo, we add nuances, and that inevitably edits it. It may pale. It may acquire a thick lacquer of emotion. The next sentence may sound a little bizarre because English grammar isn't congenial to time mirages, however: photographs tell us who we now think we once were. Photography, like most art, stores moments of heightened emotion and awareness like small pieces of neutron star. Years later, a memory's color-rodeo may have faded, or may remain vivid enough to make the pulse buck again. Each response adds another layer until the memory is encrusted with new feelings, below which the original event evaporates. Imagine a jeweled knife. First you change the handle, then you change the blade. Is it the same knife?

We tend to think of memories as monuments we once forged and may find intact beneath the weedy growth of years. But, in a real sense, memories are tied to and describe the present. Formed in an idiosyncratic way when they happened, they're also true to the moment of recall, including how you feel, all you've experienced, and new values, passions, and vulnerability. One never steps into the same stream of consciousness twice. All the mischief and mayhem of a life influences how one restyles a memory.

A memory is more atmospheric than accurate, more an evolving fiction than a sacred text. And thank heavens. If rude, shameful, or brutal memories can't be expunged, they can at least be diluted. So is nothing permanent and fixed in life? By definition life is a fickle noun, an event in progress. Still, we cling to philosophical railings, religious icons, pillars of belief. We forget on purpose that Earth is rolling at 1,000 miles an hour, and, at the same time, falling elliptically around our sun, while the sun is swinging through the Milky Way, and the Milky Way migrating along with countless other galaxies in a universe about 13.7 billion years old. An event is such a little piece of time and space, leaving only a mindglow behind like the tail of a shooting star. For lack of a better word, we call that scintillation memory.