Monday, March 10, 2014
I’m a lot smarter early in the morning than at any other time of the day. At 5:45 a.m., I excel at crossword puzzles, recall names from decades past, hum tunes from my childhood in Paris and remember the name of the President of Bulgaria (Rosen Plevneiev). By late evening I can barely spell Bulgaria, I forget my cell phone number, and don’t know what I ate for lunch.
This, I suspect, has something to do with Arthur Conan Doyle’s theory of memory, once vastly ridiculed but now coming back into fashion. The creator of Sherlock Homes believed our brains housed what is essentially a limited number of pigeonholes. These get filled as time passes--whether days, years, or an entire life--and if we are to make new memories, we must make space by ridding ourselves of old ones. Thus, in order to recall the name of a favorite new brand of quinoa, we have to abandon the name of Mrs. Winthrop, who taught Sunday school when we were eight years old and whom we never really liked much anyway. The email address of our faraway cousin will be sacrificed to the oil viscosity rating of the family SUV. The boss’ birthday will give way to the wife’s shoe size.
What really intrigues me is the short-term memory which enables us to remember a piece of information that may be useful for only very brief period. A good example of this is the memory needed to walk from point A to point B in your house to retrieve a cell phone or piece of paper. According to Simply Psychology.org, “Short term memory has three key aspects:
1. limited capacity (only about 7 items can be stored at a time)
2. limited duration (storage is very fragile and information can be lost with distraction or passage of time)
3. encoding (primarily acoustic, even translating visual information into sounds).
There are two ways in which capacity is tested, one being span, the other being what is called the ‘recency effect.’
Most adults can store between 5 and 9 items in their short-term memory.”
This idea was put forward by psychologist G. Miller in 1956, who thought that short term memory could hold 7 (plus or minus 2 items) because it only had a certain number of “slots” in which items could be stored. Miller didn’t specify the amount of information that can be held in each slot, but it has been demonstrated that if we put together a block of information, we’ll be able to store considerably more material in our short term memory.
Miller’s theory is supported by evidence from various studies, one of which used the “digit span test,” which examines the ability to recall every letter in the alphabet and numbers apart from “w” and “7,” because these had two syllables. Tests found that people find it easier to recall numbers rather than letters.
The duration of short term memory seems to be between 15 and 30 seconds, though items can be kept in short term memory by repeating them verbally (acoustic encoding), a process known as rehearsal.
The 15 to 30 second rule explains why I forget why I came downstairs. Typically, it takes me a minute to get from point A to point B, because between the two, I find a dozen things that need my attention: the cat must be fed, the coffee needs warming, the laundry had to be tossed into the dryer and the garbage can rolled to the street before the giant dump truck arrives.
Now I need to remember to post this.