Repeat After Me
Memory research is uncovering surprising new knowledge about how we remember

If I close my eyes and think of that moment more than 40 years ago when I learned that President Kennedy had been assassinated, it's as if it were happening now.

It was right after lunch. I was walking to Spanish class, when Heidi Herman passed me in the hall. She was laughing, and said, almost over her shoulder, "Bang! Bang! Someone shot the president!" She thought it was a joke. She was wearing a white cotton shirt and a navy blue skirt—that's what we all wore on Fridays to support the football team. When I arrived in Spanish class, the teacher, Mrs. Goode, sent me to the audio-visual room to get another student, Steve Aronow, who was watching TV there. That's when I knew the president really had been shot.

We all have these kinds of "flashbulb memories," startling in their clarity and detail. These memories are always personal, specific, tied to a certain time and place, and usually have an emotional component. They were first described in a 1977 study that focused on memories of the JFK assassination, a line of research that, along with dramatic advances in neuroscience, is helping to define a new direction in the study of human memory. It's a field that asks intriguing questions, such as, Why do we recall some things and not others? What roles do gender and culture play in what we remember? And what functions does memory serve?

In 1981, David Pillemer was an assistant professor of psychology when President Reagan was shot. "Drop everything else," he was advised by a mentor from his undergraduate days who happened to be visiting at the time. "Follow up on this."

He took her advice, interviewing people within days of the shooting and then again seven months later, producing the first follow-up study of the 1977 research that defined flashbulb memory. Pillemer found that most of the study's subjects retained detailed personal memories about the Reagan-shooting episode, and that their memories changed little over time.

If it had been a decade earlier, it's doubtful that either Pillemer or his mentor would have considered the project. "Before the 1970s, memory research focused on access and accuracy," says Pillemer, the Dr. Samuel E. Paul Professor of Developmental Psychology at UNH. Research tended to be laboratory-based and tightly controlled. A lot of experiments dealt with rote memorization, with subjects being asked to try to recall long lists of nonsense syllables.

The "I-remember-when..." kind of memory—a particular conversation with your minister that changed your life, praise from your 10th-grade teacher for a high school essay, the night you first met the person you would marry—these and other memories of personal episodes might be good for novelists and psychoanalysts, but in mainstream memory research 30 years ago, they were dismissed as anecdotal and irrelevant.

In the 1970s, some psychologists began to shove open the laboratory doors and take their memory studies into the real world. They didn't reject laboratory studies out of hand, but they wanted to understand memory in context, the way it happened outside the confines of a lab. They wanted to probe the influence of gender, culture and conversation on memory, and to explore what role memory plays in how people learn, how their personalities are developed and what life choices they make.

It was a controversial approach. The real world is messy. The field of psychology is sometimes viewed, especially by those outside it, as more akin to philosophy than, for instance, biology. Like sociologists, research psychologists had spent years trying to prove their research could meet rigorous scientific standards with well-controlled, double-blind, quantifiable and reproducible experiments. But Pillemer and other researchers showed that episodic memories could be codified or quantified and therefore studied scientifically.

What happens to memories after they are processed for long-term storage is unclear, says Mair, although he adds they are probably stored diffusely throughout the brain. How they are retrieved is also an ongoing memory riddle, one of increasing importance to members of an aging boomer population who fear losing, if not their minds, at least their memories.

Popular media, and even some scientific journals, are full of studies on how to have a better memory. One French study, reported in the journal Neurology, found that women, especially older women, who drank at least three cups of coffee a day performed better on memory tests. Mair points out that coffee and other stimulants may help memory just because they make people more alert; just as your mind usually works better if you challenge it and if you get enough sleep.

But the most tried-and-true way to remember things is the same way you get to Carnegie Hall—practice. "It's not jazzy," says Pillemer, "but it works. We remember things we repeat—things we go over in our minds, and out loud."

Despite the emphasis in magazines on improving memory, a lot more is known about memory consolidation than about memory retrieval. "We still don't know what memory is," Mair says of the elusive unit of memory called a trace, or engram. It's probably not a protein, since memories can last 80 years or more and proteins have short lives. The current assumption is, he says, that when memories are preserved across time there is a molecular change that affects synaptic strength. Synapses are the connections that pass signals between nerve cells. Since the human brain has 100 billion nerve cells, or neurons, each with thousands of connections to other neurons (by one estimate, it has 16 quadrillion neuron connections, with new ones developing all the time), unraveling its molecular pathway will be a monumental challenge.

But perhaps not too monumental. A recent issue of Scientific American included a story on research that has tracked the activity of more than 200 individual neurons in a specific part of the hippocampus known to play a role in forming memories of events and places in both people and mice. Lab mice were exposed to a series of alarming but not painful experiences--a puff of air on their backs, for example. An examination of their neuron firings identified cliques of neurons that fired in response to different aspects of the event, including things as specific as whether the mouse was in a black or blue box. The researchers were able to tell from the neuron firings which experience the mouse had. Someday this research might provide the basis for reading human minds—understanding, perhaps, the thoughts of someone who can no longer communicate because of disease or accident. For now, the research offers tantalizing insights into how memories may be organized and stored.

However, even if the code for memory organization is deciphered—the Holy Grail of cognitive psychologists 30 years ago—scientists still face a mountain of questions about memory, ranging from its molecular structure to how it is stored; from its role in personality and creativity to its function in civilization. The one thing that appears to be certain is that the answers to these questions will require the work of both neuroscientists and cognitive scientists working with real people and real memories.

Pillemer knows he will never grow bored with this particular line of psychology. "Many of these questions," he says, "are so basic to understanding how human nature works."

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