So-called “memory athletes,” for example, participants in the annual World Memory Championships, can rapidly learn and retain large amounts of information. Top athletes can quickly memorize a list of over 100 words and recall the list 15 minutes later. Many of these athletes credit the use of mnemonic strategies for their success. The term “mnemonic” describes a method that a person can use to remember something, for example, a rhyme like “i before e except after c” or the children’s ABC song.
In a paper recently published in the journal Neuron, Martin Dresler and colleagues report the results of a study in which they measured brain network connectivity patterns in a group of 23 of the “world’s most successful memory athletes.” They compared these brain patterns to those seen in individuals who were not memory athletes but who were matched for age, sex, and IQ. Some of these control participants were gifted students from academic foundations or members of Mensa.
The memory athletes were clearly superior at memorizing a list of words. On average, they correctly recalled 71 of 72 words after a 20-minute delay compared to an average of 40 words recalled by the control group. The investigators used functional connectivity neuroimaging to compare brain network patterns in memory athletes to those of non-athletes. They found that there were specific neural network connections that were different in the athletes.
The investigators then recruited a group of university students and taught them a specific type of mnemonic strategy known as “the method of loci.” (Participants with previous experience in mnemonic strategies were excluded from the study.) The research team tracked whether these participants’ memory abilities increased with training and whether such increases were correlated with changes in the same brain networks that are highly developed in the memory athletes. The group receiving mnemonic training was also compared to an active control group who received training in a working memory task and a control group who received no training at all. (Working memory is used for temporarily storing and manipulating information, for example, remembering why we entered a room.)
The “method of loci” involves learning how to link images of the items to be remembered to visual maps of familiar locations, for example, rooms in a house or landmarks along a route between home and work. This technique takes advantage of navigational and spatial systems that are highly developed in humans. The method of loci training used in this study was rigorous and consisted of 40 half-hour sessions spread over six weeks. The active control group received a similar amount of training in the working memory task.
By the end of training, people who were taught the method of loci had more than doubled the number of words they could recall from a list of 72 words. This dramatic increase was significantly different from the two control groups and was still noticeable four months later. When brain network connectivity patterns were measured in the group that received the method of loci training, the investigators found that the specific memory-related network differences between them and the memory athletes diminished. Furthermore, the more the trainees’ brain networks grew to resemble the networks of the memory athletes, the better their memory performance became.
The bottom line of this study is that successful memory athletes utilize the same brain network connectivity that any of us may be able to develop with training. Thus, these athletes are very good at utilizing network systems that exist in all of us. They seem to have buffed their memory “muscles” by consistent, long-term practice.
It may be possible for those of us who are mere memory mortals to train our neural networks in such a way as to greatly improve our memory function. With practice, it may be possible to become more like these memory athletes than we would ever have thought possible. In fact, based on studies outlined by Anders Ericsson and Robert Pool in their book “Peak,” it appears that many humans can become highly proficient in other cognitive (and athletic) tasks with the right coaching and high levels of dedicated, effortful practice. This is a potential story of hope for all of us.
This column was written by Eugene Rubin MD, PhD and Charles Zorumski MD.
Dresler, M., Shirer, W.R., Konrad, B.N., Muller, N.C.J., Wagner, I.C., et al. (2017). Mnemonic training reshapes brain networks to support superior memory. Neuron. 93:1227-1235.