I love this memory technique.
I like it for a couple of reasons – I found it described in Mary Carruthers’ utterly brilliant book The Book of Memory: A Study of Memory in Medieval Culture, which is about the history and practice of memory training and techniques in the middle ages. Although she described it, she never really gave it a name – at least not a simple name like “Method of Loci”. Therefore I took the liberty of naming it myself. I’ve also taken a few liberties with the methodology to make it more useful for the way my brain works.
Second, and more importantly, I find it works spectacularly well for remembering everyday numbers, especially credit card numbers.
Preparing to Use a Memory Coin
This technique works with the Person Association memory technique. In the Person Association technique, you permanently memorize a list of people that you associate with one, two, or three digit combinations. I chose to use the two digit version of the Person Association technique, so for me, Lucille Ball is forever associated with the number 27 and Bilbo Baggins is number 72.
We know that the Memory Journey technique plus the Person Association technique would let us remember a very long series of digits, but I find it a bit of a waste to use up one of my memory journeys remembering credit card numbers. Instead, I use the Memory Coin, which is a bit of a modified version of the simple Linking technique.
Since I use the two digit Person Association, each person encodes two digits. A 16 digit credit card number will require eight people.
I imagine the center of a coin contains an image of the first two people interacting in some way. Preferably, the image should be of them doing something shocking – violent, silly, and/or taboo. The first person, who represents the first two digits of my credit card number, is on the left.
To the right of the second person is the third person, slightly smaller than the second. The second person is doing something to the third person. To the right of the third person is the fourth, slightly smaller than the third. The third person is doing something to the fourth.
So far, we have a short chain of people, all interacting with each other. There is a rule when making the images and reading them. We read from the center, then to the right. The size and shape of the coin keeps us from making the chain of people too long – two people to each side is a useful limit. Then we read from the center going up. Then we read from the center going left.
For a credit card, you need two people in the center, two to the right, two above, and two to the left. Throughout the technique, keep the image fairly two dimensional, as you might see stamped on the face of a coin. This makes it easier to keep things in order.
An Example of Using the Memory Coin
Suppose my account number is 5330641188459650.
Using the Person Association technique, I translate the first two numbers as Ghandi (53) and Stephen Hawking (30). In the center position I imagine Gandhi using one of the wheels of Stephen Hawking’s chair as a spinning wheel.
Moving right, I see Stephen Hawking has attached a robotic arm to his chair, which is clamped to Mary Poppins’ (67) skirt, keeping her from flying away. But Mary Poppins and Wolverine (11) are locked in vicious battle, Wolverine slashing at Mary Poppins with his claws while Mary Poppins bops him on the head with her umbrella.
Since we are imagining a scene imprinted on a coin, it’s easy to imagine Commander Data from Star Trek (88) lying flat and rigid over the center two people, Gandhi and Stephen Hawking. Thomas Jefferson (45) is using Data as a surf board.
To the left of Gandhi is Spock (96). The yarn coming off of Gandhi’s spinning wheel is falling all over Spock’s head and shoulders, and he looks vaguely irritated by it. In anger, Spock is knocking the hat off of the head of Hyman Rickover (50), who is wearing Navy dress whites.
A Second Example
As it turns out, the coin in the picture above is telling the story of Rama’s Journey, an important Hindu epic. To people familiar with the cultural elements, this is a powerful reminder (memory aid!) of an important religious, historical, and moral teachings.
Using memory aids that link events together and tell stories is key to developing a trained memory.
Benefits and Limitations of the Memory Coin
I find the Memory Coin gives a little more structure than doing simple Linking, which helps make the memory a little more durable. The format of the coin keeps me from trying to use it to encode too many numbers. For longer series of digits, other techniques are probably better.
Also, since the coin is read from center to right, center up, center to left, there seems to be a lot of redundancy, especially around the first set of digits. I find this really helps lock in the memory.
As you move from the center and down each of the legs, I wouldn’t go more than seven people, and four or five seems to be easiest.
Connecting the central characters to the branch going up is generally the most difficult when creating links. If your number is short enough, it may be best to leave this branch off. You may be wondering why I didn’t describe going down from the center. There are two reasons – first, linking from the central figures down seems to be at least as hard as going from the center up. Also, I don’t find a need to do so. If I have a number that needs that many digits, chances are one of the other memory techniques is going to better suited to the task.
Keep this technique in mind when you see the flat illustrations common in some middle-ages tapestries or book illuminations. Are they meant to be purely artistic or are the pictures also memory aids?