Sherlock’s Mind Palace Technique Explains “Memory Athletes'” Incredible Recall

A recall method known as the mind palace technique, used by Benedict Cumberbatch’s modern-day interpretation of Sherlock Holmes, can create enduring memory enhancement that remains intact four months later, according to a study.

The findings, published by an international team of researchers in Science Advances, examined a cohort of the world’s top “memory athletes”—individuals who have shown mastery of mass information recall—and a group of non-expert participants.

The memory athletes all showed exceptional ability in using the mind palace technique, also known as the method of loci, a memory-enhancing mnemonic device originally devised in ancient Greece. Study co-author Dr. Isabella Anderson-Wagner explained to Technology Networks that although the memory palace technique has been shown previously to boost memory, unanswered questions remain: "There have only been a handful of studies exploring how [the loci technique] works in the brain and whether ‘memory champions’ are actually different from other people or better at something that can be trained." 

Memory vs Mensa

The method of loci technique is applied outside of our TV screens in events such as the World Memory Championships, where competitors flaunt their ability to recall strings of individual words. Some top athletes from the championships were tested in an initial study against a group including several members of the high-IQ society Mensa. The athletes flexed their memory muscles, recalling 72 words on average from a list they were shown previously, versus just 43 for the control group.

The researchers then divided 50 volunteers with no knowledge of the mind palace technique into three groups. One cohort was trained in the art of loci mnemonics over six weeks, whilst a second group was given working memory training. A final, passive group was given no training at all.

Memory ability and brain function were assessed before and after these training regimens whilst participants underwent functional magnetic resonance imaging (fMRI) scans. Participants allocated to the method of loci training group were better at recalling words from a list after 20 minutes (which is commonly how memory athletes are assessed in competition), averaging 62 words, versus 42 words for volunteers given working memory training and just 36 words for volunteers with no training.

Later, the method of loci group performed better than other groups at recalling words after 24 hours, racking up 56 words versus 30 and 27 for the working memory-trained and untrained groups. "The technique helps to boost long-term memory," said Wagner. 

To confirm this, the team analyzed a subset of volunteers from each group who were asked to return to the lab four months later and take the same memory tests. The volunteers who had studied the method of loci once again outperformed the other groups—they were able to recall 20 more words than they could pre-training, whereas participants given working memory training had lost all the benefits of their training.

Brain changes in the “mind palace”

To investigate whether this evidence was backed up by physiological changes in the brain, the team examined their participants’ brain activity data, recorded from fMRI scans. While fMRI does not measure neuronal firing directly. It detects changes in the blood oxygen level-dependent signal, which is influenced by local relationships among neural activity, blood flow, and oxygen consumption.

Before and after training, all three volunteer groups were presented with previously unstudied words and asked to commit them to memory. After training, the method of loci volunteers were asked to deploy their newly learned technique, placing the words that they had seen in their “mind palace”.

Whilst the team expected to observe increased activity in their trained group, especially in regions related to memory recall such as the hippocampus and medial temporal lobe, they discovered that there was a decrease in activation in these regions. Supporting this finding, their memory athletes also had lower brain activation than the non-expert control groups.

Interestingly, whilst the levels of activation decreased, levels of brain connectivity between the hippocampus and the neocortex, the site of higher thinking in the brain, increased.

The hippocampus is important for rapidly binding the elements of an experience, including items, places, and contextual details. The neocortex supports distributed representations of sensory information and conceptual knowledge. Greater coordination between these systems could help stabilize newly formed associations. The results therefore suggest that effective mnemonic training involves a combination of more efficient task processing and stronger systems-level consolidation, rather than a simple overall increase in brain activity.

The authors suggest in the paper that these findings are in line with changes in “neural efficiency,” a hypothesis that proposes that intelligent or highly skilled individuals display lower brain activity during cognitive tasks.

How else might the method of loci improve memory? Wagner and colleagues suggest that the technique’s focus on association between words and novel locations could help release hormones from the brainstem that trigger changes to the connections between brain cells. These changes would help consolidate memories of the words stored in the loci mind palace.

Evidence from healthy aging research suggests that association quality may also matter. In a 2025 study, older adults benefited when locations and target information were linked by semantically congruent associations, whereas incongruent associations did not improve their performance over a control condition.

Overall, the study shows that the mnemonic mind palace approach could be key to developing an extraordinary memory, not just "memory champions" or TV detectives. "This is a technique that can be learned by everyone," commented Wagner. "Even without constant training, I think you can very quickly find small successes with it." Wagner has used the method of loci herself to remember a grocery list. To recall milk and eggs, Wagner's mind palace, a mental version of her house, has been populated with cows and chickens in set rooms. To effectively walk a memory path, the "palace" should be a familiar location and the associations "should be as weird and novel as possible," concluded Wagner. 

This content includes text that has been created with the assistance of generative AI and has undergone editorial review before publishing. Technology Networks' AI policy can be found here.