By PT Staff, published on March 1, 2001 - last reviewed on June 14, 2012
Psychology's fascination with memory and its imperfections dates back further than we can remember. The first careful experimental studies of memory were published in 1885 by German psychologist Hermann Ebbinghaus, and tens of thousands of memory studies have been conducted since. What has been learned, and what might the future of memory be?
Some researchers believe that memories can be repressed and later recovered--the stuff that movies and lawsuits are made of-while most insist that memory is imperfect, creative and highly vulnerable to suggestion. If some of our memories are actually "false," how can we know which are true? And given that our very identity is determined by our memories, can we be sure who we really are if we can't be sure of our memories?
Technology seems to be changing just about everything these days. Can it ultimately change how human memory works? Two experts from the University of Washington in Seattle, Elizabeth Loftus and William Calvin, got together recently to review and speculate. Loftus, perhaps the world's leading expert on memory malleability, is a professor of psychology and adjunct professor of law. She has written 18 books, including Eyewitness Testimony, The Myth of Repressed Memory, and her prophetic 1980 Memory. William Calvin, a renowned expert on the brain, is an affiliate professor of psychiatry and behavioral sciences. Calvin's recent books include How Brains Think, The Cerebral Code and Lingua ex Machina. Here are highlights of their discussion.
ELIZABETH LOFTUS: A flimsy curtain separates memory from imagination. Suggestions, strong and subtle, can make people believe that they had experiences in childhood that they almost certainly did not have.
WILLIAM CALVIN: Yes, we've long known how false memories can be created. Human memory is always having to contend with the power of suggestion. After all, most happenings aren't "good stories" that fit our narrative expectations, so with retelling they get "improved."
EL: But who is most susceptible to "adopting" a memory? And who is most resistant? There ought to be a lot of individual variability in the susceptibility to false memories. Maybe it correlates with genetics, intelligence and other individual differences. Perhaps we'll develop recipes for what works with various personality types.
WC: Who am I, if not my memories--and if they're not mine, what does that say about me? It must be threatening to a lot of people, to think that their memories aren't their own.
EL: Memory is creative. There, I've said it all.
WC: But human memory isn't supposed to be creative. Facts are facts, and the past is finished. So when memory scrambles things, you get annoyed.
EL: I was very annoyed when my laptop's RAM started to shuffle the files on my hard disk. I was amazed that it could be fixed, just by removing the memory.
WC: You might think that computer memory would be a useful analogy for how human memory works. And, to some extent, it is. At first, human memory seems to be a lot like the computer's three versions: type-ahead buffer, RAM and hard disk. We, too, have a sensory buffer called immediate memory, usually seen as a ghostly image of a flashbulb, rather like the keyboard's type-ahead buffer. And we also have working memory, part of which is a short-term memory store much like the computer's RAM. It is also as volatile, because its contents can be lost following a concussion or seizure. The "consolidation" of episodic human memories is a lot like transferring files from RAM to a new file on the hard disk. In humans, the process takes days or weeks to complete, most likely because you have to strengthen synapses into a new pattern.
EL: Unfortunately, the analogy ends there. And, as the adage says, "a little knowledge is a dangerous thing."
WC: The big difference is that the human brain has no pigeonholes for data, like RAM. Human memory is cluttered. Memories don't get lost so much as they become distorted or hard to find. We may like to say that we've lost something--but often, an hour later, it pops uninvited into our consciousness, where it has been lurking all along. The serious difference between computer and human memory is that we don't pop out a pristine copy of the original event, the way a computer does. Instead, we reconstruct things as best we can from all the clutter. We guess. Often that isn't good enough, especially for a fair judicial process. Or just one's self respect, it's embarrassing to be badly wrong and we'll deny an error even to ourselves.
EL: Twenty years ago, I tried predicting memory's future. It was back in the days before eyewitness fallibility and "recovered" memories became the stuff of courtroom contests. I imagined a future world in which people could go to a special kind of psychologist or psychiatrist--a memory doctor--and have their memories modified. Little did I know.
WC: Just shows you that expertise does not equal foresight. Even you didn't foresee who the "memory doctors" of today would turn out to be, or how reckless they'd become. Or how our own state legislature would pave the way for them. Washington state was the first to waive the statute of limitations for "recovered memories" during the do-something panic over child abuse.
EL: Well, decades ago, there was ample evidence that our memories of past events can change in helpful ways, leading us to be happier than we might otherwise be. But memory also changes in harmful ways and can occasionally land us--or others--in serious trouble. On the therapeutic side, I imagine a person could have some particularly difficult memory altered. If a patient was plagued by feelings of deep sadness or worthlessness, I suppose the memory doctor might modify the memories leading to the feelings. For example, if the patient was having marital problems, the memory doctor might enhance pleasant memories involving the spouse. On a grander scale, such doctors might even be useful for curing societal ills such as social prejudice. Prejudice can be, for example, based in part on a few incidents involving a unique group of people, so the memory doctor could wipe out or alter memory of these incidents. Memory doctors would be nearly omnipotent. They would hold the key to total mind control.
WC: It would be a customized form of book burning. While a lot of people would have serious reservations about this, I can see some consumers loving it.
EL: Scores of studies on memory distortion had been conducted. People recalled a clean-shaven man as having a mustache, and even straight hair as curly. This showed that misleading post-event information can alter a person's recollection in powerful, predictable ways. In the real world, such misinformation is often available via hearsay or when people, who experience the same event, talk to one another and fill in gaps by guessing.
After years of investigation about the power of misinformation, researchers knew a fair amount about the conditions that made people susceptible to its damage. People were particularly prone to having their memories modified when the passage of time first allows the memory to fade. In its faded, weakened condition, memory becomes defenseless to misinformation.
WC: So all of that was known, long before the boom in "recovered memories" hit the courtrooms?
EL: Definitely. And we researchers would never have guessed that such a prospector version of the memory specialist was in the making. But they were. "Repressed memory therapists" went out and prospected for early childhood memories of trauma. "Are you sure you weren't abused?"
In the process they appear to have inadvertently created false memories of the worst sort in some of their clients. This is not to say that there haven't been many thousands of genuine cases of child abuse. Psychotherapy has surely been a comfort to many victims. But the aggressive use of memory work led some patients to false memories of child molestation, ones that were a blend of dreams and movies, made real only by suggestion. In some cases, what surfaced were violent traumas spanning years of the patient's life. If these were false memories, the patient was surely being harmed.
WC: Even with the best intentions and the best of precautions, the cure is sometimes worse than the disease. When the therapist is ill-informed, it happens even more often.
EL: So where do we think the field of memory is going now?
WC: Better research ideas can happen anytime, but what's more predictable is the applied technology and its legal ramifications, lust remember what fingerprint and other physical evidence standards did to the former reliance on sweating a confession out of a suspect, with all its hazards of suggesting a nonexistent memory. Once webcams become ubiquitous, they too will reduce the number of times that the unsupported word has to decide things.
EL: Webcams in preschools are truly amazing. We're raising a whole generation used to being "on camera." There's a new video monitoring system in which parents can go into a web browser, enter a password, and have access to a live video feed of their child in daycare at any time, no matter where in the world they tap into the Internet. Check once, or watch all day from a little window in one corner of your computer screen at work. The idea does have its drawbacks: Overprotective parents can check compulsively. Other parents can watch your child misbehaving. Maybe they'll sue you, too, if the video file shows your Johnny hitting their Susie.
WC: The novelist David Brin explores the possible effects of tiny cameras mounted in your eyeglass frames in one of his novels. "Peepers," he called them, and depicted disgusted adults using them to record misbehaving youths riding on public transit.
EL: A publicly supported surveillance trend began in Britain nearly 20 years ago. They installed 60 remote-controlled video cameras at various "trouble spots." Where they put them, crime dropped by half.
WC: Just think what ubiquitous webcams and eyeglass cams will do to make the public aware of what the eyewitness memory researchers have been saying all along: Eyewitnesses are often badly mistaken, after some time has passed. The public is used to the instant replays to prove the referee wrong on occasion. Soon we'll have a courtroom industry devoted to mining video files, just to supplement eyewitness testimony. Just as DNA has changed the standards of evidence for rape convictions, the webcams and email archives will change the standards for all sorts of things.
EL: The Webcam is already small and inexpensive, with a price tag of less than a hundred dollars. Most popular are the property-surveillance devices. You can check on your vacation home via a simple phone call. But you can also broadcast your video monitor over the web so anyone can look.
WC: And there will be automatic face recognition. A display on your eyeglasses might allow you to view the results of a database search. The person's name would be flashed on the inside of your eyeglasses. When you ask, "What is her name?" the traditional limitations of human memory will be transcended.
EL: So what's the next decade of memory therapy going to be like? Psychotherapy with a pharmaceutical booster? I can envision 21st-century memory doctors helping clients with their academic performance by prescribing additives for the coffee they drink before an upcoming test. They might even begin their psychotherapy sessions with a drug that enhances the malleability of memory, making the patient more susceptible to positive suggestions that occur later in their session.
WC: More of human memory will move offline. We'll rely more on digital storehouses full of video and audio files of our lives. It'll happen because digital storage is cheap--and hopefully because we also realize how unreliable human memory can be. Maybe some of the storehouses will be portable, like today's music for joggers, and will provide you with help in remembering people and places.
EL: But when we do get the false memory recipes down pat, we'll be left with critical questions. Who controls that technology? What brakes should be imposed on police, lawyers, advertisers and others who try to manipulate people using these findings? When memory creation technology becomes readily available, how will society protect itself from misuse? We'll need to constantly keep in mind that memory, like liberty, is a fragile thing.
READ MORE ABOUT IT
The Myth of Repressed Memory Elizabeth Loftus and Katherine Ketcham. (St. Martin's Press, 1994)
Witness for the Defense: the Accused, the Eyewitness, and
the Expert Who Puts Memory on Trial Elizabeth Loftus and Katherine Ketcham. (St. Martin's, 1991)
Lingua ex Machine: Reconciling Darwin and Chomsky With the
Human Brain William Calvin and Derek Bickerton (MIT Press, 2000)
The Cerebral Code: Thinking a Thought in the Mosaics of the Mind
PHOTO (COLOR): The Memory Doctors: Elizabeth Loftus and William Calvin