Life Is Seldom Unforgettable : But experts say we often remember things that never happened--and can’t recall things that actually did. : SCIENCE FILE / An exploration of issues and trends affecting science, medicine and the environment

As part of the Whitewater hearings, Hillary Rodham Clinton has been asked to remember a great many events that happened two or 10 years ago. When she can’t remember, critics accuse her of lying. To prove their case, they point out contradictions between what she remembers and the memories of members of her own staff.

Clearly, the critics conclude, someone is not telling the truth.

But this kind of reasoning has memory experts gritting their teeth.

“It’s ridiculous,” said University of Washington memory expert Elizabeth Loftus. “People have forgotten far more important things than how many meetings they had or who was at them.”

For example, a significant portion of people involved in minor car accidents had forgotten the incidents when interviewed merely a year later, Loftus said. In fact, psychologists say that memory is notoriously unreliable.

“Memory is not a literal recording,” says Harvard psychologist Daniel Schacter. “It’s more like a kind of [evolving] sculpture.”

Over time, psychologists say, people refashion their memories so drastically that most of us routinely remember things that never happened--while forgetting things that actually did.

Both Schacter and Loftus brought up the confirmation hearings of Supreme Court Justice Clarence Thomas and the testimony of Anita Hill as a classic case of the public misperception of the basics of memory.

“Everyone assumed that one of them was lying,” Schacter said. Equally likely, both researchers said, is that Hill and Thomas were both telling the truth--and honestly remembered the same events very differently. “It is possible that each took out their own interpretation of what might have started out as a common reality,” he said.

Arguments about who remembers what--and who’s lying about what they remember--are as common among friends and spouses as among public figures. UCLA psychologist Robert Bjork cites those heated arguments people get into with their husband or wife over who said what. “You wonder how you could have married such an ignoramus,” he said. “You swear on the Bible and all that. You’re very confident about that representation you have in your memory [of what was said].”

Confidence, however, has nothing to do with accuracy. In most cases of disputed memories, there’s no way of telling who’s memory is closer to the truth. But the Watergate scandal provided an unprecedented opportunity to compare memories with the real thing--thanks to the notorious tape recordings made by Richard Nixon.

One of the prime figures in the affair, White House counsel John Dean, was regarded as a human tape recorder because he remembered even arcane details of events and conversations. However, a psychological study that compared Dean’s memory of events to recordings found that while Dean was accurate about the gist of most conversations, “he was often grossly wrong about what was literally said,” Schacter said.

In everyday life, it’s impossible to compare memories to tape recordings. Chances are, no one will ever know whether Clinton’s memory lapses were simply normal byproducts of the way our brains work or something more sinister.

But laboratory studies have revealed some interesting biases in the way we remember things. For example, Loftus says, memory often acts as what psychologists call “a prestige-enhancing mechanism.” In other words, memory serves as a built-in ego booster.

“We remember we gave more to charity than we [actually] did, we took more airplane trips, we had kids who walked and talked earlier than they did, we voted in more elections,” Loftus said.

Loftus performed a study of what people remembered about their voting habits. When she called people a week after an election, and asked if they voted, “some small fraction will tell you they voted when they didn’t.”

And over time, the effects of memory distortion only get worse. Through a process psychologists call “rehearsal,” people play their memories back to themselves again and again, each time altering them a bit in the retelling, until the original event may have little in common with the memory.

“As time passes,” Loftus said, “memory fades, and it becomes more vulnerable to alteration, distortion, sublimation, suggestion from outsiders or from our own thoughts and ideas.”

The tricks that memory plays are notoriously difficult to pin down because they occur at three different points in the process.

First, the information is recorded. But laying down “memory traces” isn’t like making a literal copy, Bjork says. “We’re very selective. We read body language and tone and make assumptions about what points we think are going to be made, what ulterior motives [the person we are talking with] might have.”

Then, we rehearse the memories, embellishing them as we go along.

Finally, we try to retrieve them. But retrieval is also selective. In part, retrieval works on a need-to-know basis. This can actually be an advantage, Bjork points out.

Your brain wouldn’t be very efficient if it called up every phone number you ever had each time you needed to recall your phone number.So your memory selects only what’s most important.

Unfortunately, some events become significant only in hindsight, Bjork said. For example, it’s possible that some of the conversations public figures can’t remember really weren’t important enough at the time to recall.

“People wonder, why didn’t they remember something so significant?” Bjork says. “But at the time, it may have seemed ordinary and mundane and gotten mixed in with the context of everyday events.”

Schacter, for example, vividly recalls going to a Yankees baseball game when he was 12, with his brother who was a few years younger. “I remember in particular that the Yankees lost, and he [his brother] was very upset, he was crying.”

The younger brother, although certainly old enough to remember, has no recollection of the event. Schacter thinks it’s because that day was his own birthday, and therefore special. For his brother, it was just another Yankees game. “And he always cried when the Yankees lost.

The fact that memory isn’t like a tape recording is good news in at least one respect, Bjork says. “People think of memory as a tape or box that gets filled up, and there’s no more room on it. Actually, it’s just the opposite: The more you store, the more room there is for storage.”