The Advantage of Forgetting
Contrary to the Teachings of History Teachers:
The Advantage of Forgetting
My mother has anawful memory. When I was 12 yearsold I discovered that my aversion to apples was actually because whenever I hadthem as a child my throat would get tight. Unfortunately, I didn’t know this until one day I rapidlyate an entire apple before horseback riding only to have my throat close off asI mounted my pony. To this day mymother offers me samples of apple crumble as we are grocery shopping. It doesn’t worry me though, because Iknow that in an emergency all my allergies would come streaming back into hermind. What has always worried meis that I could end up with her dysfunctional memory. I don’t honestly remember much of my elementary schoolyears. Middle school is only ahaze. Now even high school isgetting a little fuzzy. When myhigh school friends bring up an inside joke from freshman year the chance thatI will remember it is getting lower and lower. I do remember the most bizarre details though. For example I can still draw a detailedfloor plan of the day care my family left me at every day for a week during awhite water rafting trip we took when I was 7. Considering our memories are such an integral part of ourpersonalities, the things we do remember sometimes seem so bizarre. It may often seem illogical, butforgetting the past allows one to not be burdened by mistakes. We remember thelessons while forgetting the facts, and that allows us to remain functionalmembers of society.
Thegenerally accepted classifications of memory are sensory, short-term, andlong-term. Each type performs adifferent necessary task, and together they make up our entire experience ofthe world around us. Each typevaries in both what is remembered and how long it is remembered for, but noneholds the full picture.
Sensorymemory has three main characteristics. First, it holds a significant amount of detail. The secondcharacteristic is that the information retained is entirely un-interpreted. Finally, this information is held onlyfor about half a second[i]. And example of sensory information iswhen one briefly glances at an object and then closes one’s eyes. In that instant you can remember withgreat detail what the object is, but that image fades extremely rapidly. Also, while you held that image youthought only of its physical presence, not its larger meaning.
Theimportant information from sensory memory is transferred into short-termmemory. Short-term memory, or“working memory”, can only hold a small amount of information at any point intime, but it includes our own awareness, feelings, and thoughts of thesensations. It is within theshort-term memory that we are able to process and perform metal work upon theinformation. Short-term memoryincludes not only the sensations around us at any point in time, but the recentmental processing we have performed on any topic. The average person is only able to hold 7±2 different unitsof thought in their short-term memory at any point in time, but this can beimproved by “chunking” bits of information together. For example when trying to remember a persons phone numberit is often impossible remember it as 10 discrete numbers, but it becomes mucheasier if “chunked” into three groups of 3, 3, and 4 numbers[ii].These 7±2 different units of information compete within the short-term memoryfor dominance, with the most important pieces slowly edging out the lesscritical. Overtime these importantpieces of information are transferred into the long-term memory, while theothers fade away.
Long-term memoryis stored as the meaning of the information. Long-term can be considered unlimited. The brain is estimated to hold about100TByte, but the cumulative data gathered over a 70-year lifetimes is onlyestimated to be about 125MByte[iii].Furthermore, unlike sensory or short-term memory once a piece of informationhas entered long term memory it is much less likely to be truly forgotten. It may be difficult to retrieve due tolack of use, but it still remains. Another unique characteristic of long-term memory is that the pieces ofdata in long-term memory are extensively interconnected. Physiologically short-term memory isthe temporary communication between neural connections. The transferring of information fromshort-term to long-term memory is the process of potentation. Long-term Potentation (LTP) is theenhancement of those short-term memory neural connections through simultaneousstimulation[iv].
As piecesinformation work their way through sensory and short-term memory to long-termretention they become slowly weeded out. It is only through repeated use that data can works its way intopermanent recording. Suchselective memory is sometimes extremely frustrating. Life would be so much easier if I could remember everypersons name when introduced to them at a party. I wouldn’t have to study chemistry if I remembered everyword my teacher said. Rememberingevery piece of information our brains ever received would make our lives somuch less stressful. Wouldn’t it?
James McGaugh, anexpert on the human memory system, was recently contacted by a woman who knowswhat it feels like to never forget. AJ, she has chosen not to disclose her real name, can remember whatoccurred on every day of her life since she was 13 years old“automatically”. If you give her adate she doesn’t have to think about it before she rattles off historical andpersonal events that occurred on that day. Prior to 13 she has to contemplate it a little harder, but hermemory is remarkable nonetheless. In a letter to McGaugh AJ wrote, “Whenever I see a date flash on thetelevision (or anywhere for that matter) I automatically go back to that dayand remember where I was, what I was doing, what day it fell on and on and onand on and on. It is non-stop, uncontrollable and totally exhausting”[v]. AJ is the first person to have beenconfirmed to suffer from hyperthymesia. Hyperthymesia is a condition in whichthe individual has an ability to recall even the most trivial of memories aboveand beyond the average individual[vi]. If left uninterrupted after being givena date AJ will effortlessly and automatically explain everything that happenedon that day, and then her discussion of that day will flow into all of thememories that the events of that day remind her of. Scientists have performed extensive testing to show thatAJ’s memory is genuine.
But AJ’s memory isnot all fun and games. Unlike therest of us who can let a tiny event in our lives go, AJ explains that, “I onlyhave to experience something one time and I can be totally scarred by it… Ican’t let go of things because of my memory”[vii]. As a result of her remarkable memory(although she denies a link), AJ has over 20 phobias. She can recall the dates and events that triggered a numberof her phobias. Her life has beenplagued by bouts of depression and anxiety. Along with the good, she remembers every time shedisappointed a friend and every childhood embarrassment. She is never able to move past thesemoments as they are always with her.
AJ’s story showsas that forgetting is just as important to growing up and the memories we holdon to. We keep with us the lessonswe have learned while letting the pain and suffering that taught us fade into themists of our pasts. By lettingthese memories get buried in the depths of our neuronal web we are able to moveon to the future without being paralyzed by our pasts. Forgetting the inside jokes of my highschool years allows me to leave behind the embarrassing trials those jokes weremeant to cover. In the end those who forget the past may not be doomed torepeat it, they are free to try again.
[i] "Cognitive processes." Thinkquest.16 May 2008<http://library.thinkquest.org/26618/en-5.2.2=sensory%20memory.htm>.
[ii] "Chunking." Memory Techniques. 16May 2008 <http://daphne.palomar.edu/stat/mark/ stm%20chunking.htm>.
[iii] Landauer,Thomas K. (1986). "How much do peopleremember? Some estimates of the quantity of learned information in long-termmemory". Cognitive Science: A Multidisciplinary Journal 10:477-493.
[iv] "Learning, Memory, and Long-termPotentiation." Kimball's Biology Pages. 17 Dec. 2006. 16 May 2008<http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/L/LTP.html>.
[v] Parker, Elizabeth. (2006). “A Case of UnusualAutobiographical Remembering”. Neurocase. 12, 35-49
[vi] "Hyperthymesia." Health Dictionary andResearch Guide. 123explore! 16 May 2008<http://www.123exp-health.com/t/01081476083/>.
[vii] Parker, Elizabeth. (2006). “A Case of UnusualAutobiographical Remembering”. Neurocase. 12, 35-49