Akira Haraguchi, a man residing in Japan, was able to memorize 111,700 digits of pi. I am not sure about everyone else, but I have been able to memorize 3.14159, and this number was looped around more of my classroom walls than I would like to admit. My six memorized digits match the 7 +/- 2 digit span task that we have learned about. Of course, we now know that people can hold 7 +/- 2 chunks, so the only question is, how did Haraguchi manage to put 111,700 digits into five to nine chunks? Has he increased his working memory? This is where it gets complicated.
Haraguchi assigned each digit several syllables. In his interview, he reveals that the number zero is assigned the syllables o, ra, ri, ru, re, ro, wo, on, or oh. This puts his chunking at the maximum of nine, and he continues this for the rest of the numbers. Of course, there are ten number (0-9) in which he must memorize, so it might be assumed that his chunking capabilities are slightly higher than the average person’s. Now we know that each number is assigned various syllables, but how does that help him remember the order of pi? Haraguchi reveals that he has created over 800 stories by combining the syllables into words, the words into sentences, and so on.
This is utilizing deep processing, since he is giving meaning to numbers, which will lead to better recall later. Additionally, he sees pi as equal to saying the Buddhist mantra, which indicates that he has made it personal. This also helps with recall. His working memory has not (and could not) increased, but he has found a way around the five to nine digit “limit.” This is a lot more exciting than the 110 digits memorized by Steve using race times. The next question is: how could Haraguchi possibly remember the exact wording of all these stories, and in the right order?
One way Haraguchi might be ensuring that this does not occur is by rehearsing. He recites 25,000 digits a day, dedicating three hours of his life to saying numbers by telling stories. As Reisberg discussed in chapter eight of Cognition, along with nearly every teacher I have had since high school, you are more likely to be able to recall something if it was learned well originally, and if you revisit the material later by practicing it. Haraguchi is essentially quizzing himself on part of pi every day, helping him to remember the order of the story, and thus the number.
I know The Guardian is not the best place to find “real” psychological news, but I was disappointed that there were not more details about how he memorizes pi. The chunking and meaning all make sense, but even by practicing 25,000 digits a day, how does he memorize 111,700 digits without mixing up the order of the stories or using a synonym for a word (I know that I never end up using the exact wording of a story twice). This is briefly explained when Haraguchi states that the first hundred digits are all about humans, but if there are over 100,000 digits and the first story chunk is only one-hundred, the rest must be much larger chunks in order to meet the 7 +/- 2, or he has much more than nine chunks.
My guess is that he splits his chunks into chunks, but did not mention it during the interview. Perhaps the first 15,000 digits are stories about living things, which break up into humans, cats, dogs, trees, etc. The next 15,000 may be household items, and include stories about couches, silverware, etc. Perhaps even these categories are split into smaller parts. I initially thought it would be impossible to memorize over 100,000 digits (the 110 discussed in class seemed incredible!), but I now believe that with many years of dedication and practice, it is possible. This does, however, leave me with the question: is there a limit to how many chunks within chunks a person can have? My best guess is yes, since the 7 +/- 2 chunks seems to hold true.
Here is a diagram I created to explain my best guess of how Haraguchi memorizes so many digits. He stated that he uses the ones I labeled “humans,” “words,” “syllables,” and “numbers,” and I inferred the “living things” and “staying positive” in order to explain how 800 stories can be placed in 7 +/- 2. Notice that there are six steps that I created for my possible explanation, which still goes along with the chunking theory.
Although this article was mostly informal (such as asking Haraguchi how he plans on spending March 14), the questions and information about how he is able to remember so many digits fascinated me. I was disappointed that there were a few gaps I had to do my best to fill in so that the cognitive psychology would make sense (there is no way 800 stories are only split into humans, animals, and plants because that would be many more than nine stories per genre), but I would be interested in future interviews with Haraguchi explaining his process of memorization in more detail. Is my theory correct? Do you think you could memorize over 100,000 digits? This kind of memorization would require a lot of attention and effort; probably more than I have.