With the right training, people can improve their memory almost to the level of the world's top-ranked memory athletes — and the effect can be seen in brain scans.

Memory athletes worldwide compete to memorize hundreds of words or other information in minutes. Martin Dresler at Radboud University Medical Centre in Nijmegen, the Netherlands, and his colleagues used functional magnetic resonance imaging (fMRI) to scan the brains of 23 of the top 50 athletes and compared the scans with those of untrained ('naive') people. The team then used a technique popular among memory athletes to train the naive control group daily over 40 days. The researchers found that those in the naive group roughly doubled the number of words they could recall, remembering up to 60 from a list of 72 — nearly matching the performance of some athletes.

In the fMRI scans, changes in brain connectivity patterns in the naive group before and after training looked similar to the differences between untrained volunteers and memory champions. Connections grew stronger between key areas of the cortex involved in learning, memory processing and the linking of new and old knowledge.

Neuron 93, 1227–1235 (2017)