BEHAVIOR

A probe of the mysteries of fallible memory

Provocative research hints that memories change with time

Pat Ohlendorf February 23 1981
BEHAVIOR

A probe of the mysteries of fallible memory

Provocative research hints that memories change with time

Pat Ohlendorf February 23 1981

A probe of the mysteries of fallible memory

Provocative research hints that memories change with time

BEHAVIOR

Pat Ohlendorf

Whether people remember their first day of school as excruciating or exciting, or last year’s promotion as an honor or an unkind kick upstairs, they tend to trust that the “true memories” can be summoned with honest self-scrutiny. Psychoanalysts have thought so, earning their fees by helping patients uncover the memories of repressed seminal incidents in their early lives. Most psychologists have concurred, assuming that, like data in a computer or books on a library shelf, memories are in “permanent store.”

Now, however, University of Washington psychologist Elizabeth Loftus concludes that memories can change, sometimes so radically that the original memory disappears. “Irrevocable transformations of memory could occur

on occasion, just as caterpillars become butterflies and cheese turns to mould.” If she’s right, attempting to dredge up the absolute truth from our personal pasts may be futile.

By exposing her test subjects to leading questions, conversations and misleading photographs after they had witnessed a simulated accident, Loftus found that their original perceptions could often be wiped out, replaced by a composite of fact and fiction. A minor collision (see illustration) followed by an experimenter’s loaded question one week later (“About how fast were the cars going when they smashed into each other?”) led many test subjects to “remember” high speeds and shattered glass. Psychological and even financial rewards failed to recover the original perceptions, which the subjects had described immediately after the event. The results of Loftus’ own experiments,

combined with descriptions of many court cases that relied heavily on fallible human memory, have given Eyewitness Testimony (1979) far-reaching legal implications.

In her latest book, Memory, Loftus moves outside the courtroom to question the permanence of memory in general. We remember in bits and pieces, Loftus believes, and fill in the gaps with whatever seems logical according to our own biases. “Memory seems to shift in a prestige-enhancing direction,” she says. “We remember that we gave more to charity, or that in a joint venture we contributed more than our partners did.” Once the distorted recollection has taken hold, there may be no recovering the original impression. “I think of memory,” explains Loftus, “as someone sitting down at a computer terminal, pulling up a memory file, editing it, putting the updated memory into the computer and throwing the old one away.” While many psychologists may be scandalized by the suggestion that memories undergo protean transformations, Stanford neuropsychologist Karl Pribram expresses sympathy for Loftus’ position. “In the brain there must be something analogous to silver grains on a film, where perceptions are stored—probably protein molecules distributed on the surfaces of neurons [brain cells].The brain, like the rest of the body, is dynamic. Within about a month there’s a complete turnover of proteins. If new forces are operating on us during that month, the reshaping of the molecules may be somewhat different. You see,” concludes Pribram, a former brain surgeon, “you’re not really the same person you were 10 years ago. You just think you are.”

“That’s simply not true,” counters Boston neuropsychologist Marcel Kinsbourne (formerly of the University of Toronto), who, with Pribram, is credited with narrowing the gap between psychology and neurology. “The fact that there’s a dynamic turnover of proteins tells you nothing about any psychological theory.” While Kinsbourne does not question Loftus’ observations (“It’s obvious that we remember selectively”), he feels that Freud’s explana-

tion is more reasonable: the original event we have trouble recalling has not been lost, but rather buried by an interpretation we want or need to believe.

Kinsbourne, a former neurologist, describes the brain as a network of neurons that fire in a particular pattern in response to an experience. “When we experience something, some of those

neurons fire in a particular pattern. Memory is re-experiencing; it’s simply the reactivation of that same pattern of neurons that occurred in the first place.” In his view, distortions in memory result from the reactivation of a similar neuronal pattern that is more powerful emotionally; and the proper cue will restore the original memory.

“Let’s say that I’m telling you how fantastic I was at sports when I was 11. I could really impress you. However, if you happened to know the real events and asked me, ‘But what about that time?’ then presto!— that supposedly changed memory would reassert itself.”

“I’d be interested to know,” he adds, “whether the memory distortions of Beth Loftus’ subjects could survive hypnotic regression.” But according to Loftus, hypnosis is just as apt'to evoke skewed or even fabricated memories as a fully conscious search.

Critical as it may be to the law and to psychoanalysis, the question of the permanence or impermanence of memories may never be resolved. For, if the “true memory” fails to emerge after an experimenter has tried every conceivable means to unearth it, then, as Loftus says, “the critics would still argue that we had simply not gone far enough.” On the other hand, if the original memory did resurface, the critics could conclude, in Kinsbourne’s words, “Well, gee, the distorting influence just wasn’t powerful enough.”

It’s all a matter of belief, according to well-known memory psychologist Endel Tulving of the University of Toronto. “Since we do not yet know how to determine whether memory traces are changed beyond recovery or whether they remain intact, I’m willing to remain agnostic.”

What Tulving, among others, finds encouraging about Loftus’ work is its bent toward real-life problems. Traditionally, psychologists have studied memory in controlled laboratory experiments of the memorize-these-numbers variety. Such experiments, according to linguist Peter Salus, who studies memory structures for language, cast no light on “the sorts of things people do every day—like, when you hear music blaring out of a record store, suddenly remembering the fragrance of the perfume you were wearing 15 years ago when you first heard that song.”

To Salus, who left the University of Toronto for the University of North Florida last year, studies such as Loftus’ lead researchers to ask better questions. And better questions are needed, he says, because “face it, we still know very little about what goes on inside those four pounds of fat and water that each of us carries around in our heads.”