The Tenuous Past: Memory and the Ways it Fails

Biology 202
2004 First Web Paper
On Serendip

The Tenuous Past: Memory and the Ways it Fails

Dana Bakalar

"I remember it like it was yesterday!" you say. But how well do you really remember it? How well do you remember yesterday? Here's a quick quiz: What time did you have lunch yesterday? What exactly did you eat? What did you say? What did the people around you say? If you read the paper yesterday, name all the stories you read and summarize them briefly.

Don't remember yesterday as well as you thought? Don't worry, nobody does. Our memories are often thought of as recording devices, mechanically noting what has happened during the day and replaying these events like a tape. In truth, memory is a function of the brain, which is constantly in flux, organic, and does not behave like a machine. Your memory can be affected in many ways by many things, which can cause you to forget, to change memories around, to repress memories, and even to invent completely new ones!

This is of no small importance, because our only evidence that the past occurred comes from our memories. In what ways, then, can memory fail us?

Dr. Daniel Schacter of Harvard University lists "7 Sins of Memory," ways in which our memories fail us. His list features :
Transience, absentmindedness, blocking, suggestibility, bias, persistence, and misattribution (5). Most of these sins are things we experience in everyday life. When something you read last week isn't as clear now as it seemed then, that's transience. When you forget where you put your book or forget that you have to be somewhere, that's absentmindedness. Blocking is the "temporary inaccessibility of stored information," such as a person's name or a word. Suggestibility and misattribution go together, since memories can incorporate misinformation and also BE misinformation. Suggestibility is the "incorporation of misinformation into memory due to leading questions, deception and other causes," and misinformation consists of 'remembering' something that did not occur. Persistence is slightly more abnormal, and the inability to get a thought out of your head that it characterizes is common in post traumatic stress disorder.

To this list, some would add "repression," the conscious or unconscious suppression of traumatic memories. Repression was first conceived of by Freud, who felt that people could push memories out of their awareness (1). This theory enjoyed new fame in the 1990's, when hundreds of people, mostly women, 'recovered' repressed memories of abuse, fueling a Satanic Ritual Abuse scare during which many people were convicted of heinous crimes they may not have committed (8).

Michael C. Anderson et al did a study to see whether repression had any physical signals, whether the brain changed when people tried to repress a memory. They set up an experiment wherein subjects looked at a pair of words, memorizing the association. Then, after performing either a task involving thought or one not involving thought, were shown one half of the word pair and either asked to think of its complementary word or to suppress thought of it. They took MRI's of the subjects throughout the process and found that "Controlling unwanted memories was associated with increased dorsolateral prefrontal activation, reduced hippocampal activation, and impaired retention of those memories," and that "Both prefrontal cortical and right hippocampal activations predicted the magnitude of forgetting" (1). This means that there is a physical mechanism for repressing memories. This is important, as it means that memories can be buried and lost, impairing ability to remember entire portions of life.

On the flip side of repression is memory fabrication. This is affected by the 'sins' suggestibility and bias, but is really a case of misattribution. Sometimes we remember things that someone else told us about, things that we dreamed, or things we just made up. University of Washington memory researchers Jacquie Pickrell and Elizabeth Loftus conducted an experiment wherein they showed people a fake advertisement in which the reader is described visiting Disneyland and meeting Bugs Bunny. Later, one third of participants reported that they knew they had or remembered having shaken Bugs' hand. This, of course, cannot be true, since the Bugs Bunny Character is a trademark of Warner Brothers and not Disney (2). This is quite significant in everyday thought and in advertising. If imagination or suggestion can give rise to memories as real as those of actual events, how can we tell what has actually occurred and what has not?
Loftus points out that this is a memory process that advertisers use when creating "nostalgic ads." A company such as Disneyland or McDonalds can prompt consumers to create false memories of having had positive experiences with their products and services in the past, increasing your likelihood of returning (2).

Besides the more everyday ways memory fails, there are many diseases which can affect it. Alzheimer's is probably the most well-known of these. Alzheimer's impairs judgment and changes personality as well as affecting memory (6). It occurs most often in older people, who make up about 50% of the population with the disease, and is very rare in individuals under 40 (7). The memory loss in this disease, as well as in other brain-altering diseases, comes form changes in the physical structure of the brain, rather than from normal brain mechanisms.

Overall, then, our memories, which we depend on to report the past and to form our personalities, are in fact extremely mutable. They can be affected and changed by things we think, things we see, diseases we get, and they can be fabricated out of suggestion or imagination. Since these flawed memories are all we have, we must form a world view based on the premise that they are more or less accurate interpretation of the past; this premise is usually useful and necessary, but can sometimes cause problems. How much should we trust eyewitness reports of crimes, for example? Or the reports of a repressed abuse memory?
How can advertisers manipulate us using these memory flaws? And who are we really if our memories of our selves and our interactions with others are so changeable?

I leave you with those thoughts; but remember, you don't remember yesterday well as you might have thought!

References

1)Science Magazine, Anderson, Michael C. et al. "Neural Systems Underlying the Suppression of Unwanted Memories".

2)University of Washington, "'I Tawt I Taw' A Bunny Wabbit at Disneyland."

3)American Psychological Assosciation, "People Think They Remember."

4)PSYCHIATRIC ANNUALS, Loftus, Elizabeth. "The Formation of False Memories."

5)APA ONLINE,
Murray, Bridget. "The Seven Sins of Memory."

6)WebMD Health,"Alzheimer's Disease: An Overview."

7)WebMD Health, "Who is Affected by Alzheimer's Disease?"

8) Loftus, Elizabeth. The Myth of Repressed Memory. New York: St. Martin's Press, 1994.

Comments made prior to 2007

I was having lunch with my 17 year old daughter a couple weeks ago.

We were talking about rearing children. She said, "You know, daddy. I have forgiven you for whipping me with a belt." I have never whipped my daughter. My father, a dry land farmer of the depression, Pearl Harbor and WWII veteran, used to use a belt, quite freely. I swore I would never whip my children.

But my daughter says she remembers me whipping her. She doesn't know the specific incidents, but remembers me whipping her. I suggested it may be she remembers some of her friends being whipped by their parents (we lived in the deep south, and whipping is common. She became agitated, and insisted I had whipped her.

I do know that because I have always protected her and treated her like an adult, she has developed strong opinions and can be argumentative, even while spening hours playing on the internet and computer games. I suspect she is developing a set of fabricated memories....and I don't think I like it ... D. Madsen, 27 November