Mind palace: how Sherlock's technique really works (and how to build one)

A mind palace is the memory palace technique, also called the method of loci: you place vivid images of what you want to remember at fixed spots along a route through a place you know well, and walk that route in your head to recall them. Sherlock made the name famous, but the technique is more than two thousand years old, and you can build your first mind palace this evening.

This article explains where the term comes from, what Arthur Conan Doyle's original Holmes said about memory, what the research shows, and how to build a mind palace in six steps. For the full technique with exercises, see our guide how to build a memory palace, step by step.

Where the term mind palace comes from

The BBC series Sherlock, with its first episode on 25 July 2010 and its last on 15 January 2017, brought the words mind palace to millions of viewers: the title character uses mind palaces to remember things. The term is now simply another name for the method of loci, next to memory palace and journey method.

The original Sherlock Holmes, in Arthur Conan Doyle's first Holmes novel A Study in Scarlet (published in December 1887 in Beeton's Christmas Annual), talks about memory differently. In chapter II, The Science of Deduction, he tells Watson:

"I consider that a man's brain originally is like a little empty attic, and you have to stock it with such furniture as you choose."

A fool, he goes on, fills that attic with every kind of lumber, so useful knowledge gets crowded out; a skilled worker keeps only the tools he needs, in perfect order. This brain attic is about choosing what to keep and keeping it tidy. The mind palace adds the step that makes things easy to find again: every piece of knowledge gets its own place along a route.

What a mind palace really is: the method of loci

The founding story comes from Cicero's De oratore. The Greek poet Simonides left a banquet just before the roof collapsed; he could name every guest because he remembered where each one had been sitting. The oldest surviving manual, the Rhetorica ad Herennium (around 80 BCE), gives the rules that still hold: use real places you can picture, keep them distinct, and make the images striking, because ordinary things slide out of memory.

It works for ordinary people too. In 2003 a team led by Eleanor Maguire scanned ten people with exceptional memory: they did not have higher intelligence or a different brain structure, and most of them used the method of loci. In 2017, Martin Dresler and colleagues trained beginners for 40 days, 30 minutes a day: they went from recalling 26 to 62 words from a list of 72.

What the series gets right, and what it skips

• Right: memory is tied to places, and the images are vivid and specific.
• Skipped: building the palace. In real life you choose a route, place each item on purpose and walk it again a few times. Without review, the images fade within days.
• Skipped: limits. A mind palace holds things in order. It does not make you understand them, and it does not deduce anything for you.

How to build your own mind palace in 6 steps

1. Choose a place you know by heart. The flat or building where you live, your school, a friend's place you visit often. You must be able to picture it without effort.
2. Fix a route. Always walk it in the same direction: entrance, hallway, kitchen, living room. The route keeps the order.
3. Pick distinct spots. Start with ten, each clearly different from the others: the doormat, the coat rack, the mirror, the table.
4. Make each item an exaggerated image. Big, moving, strange or funny, with sound or smell. Let it do something with the spot.
5. Walk it once, then test yourself. Walk the route with the list hidden and recall each item before you check.
6. Review. The same evening, the next day and after a week. Then add a second palace for a new subject, instead of crowding the first.

A small Sherlock-style exercise

Five things to remember from a case: a muddy boot, a train ticket, a red umbrella, a torn letter, a cup of cold tea. Route: front door, hallway, kitchen, sofa, window.

• Front door: a giant muddy boot is wedged in the door, and mud oozes over the doorstep.
• Hallway: train tickets rain down from the ceiling and stick to your coat.
• Kitchen: a red umbrella opens by itself inside the oven.
• Sofa: the cushions are made of torn letters that rustle when you sit down.
• Window: cold tea runs down the glass on the inside.

Close your eyes and walk it backwards. If you can, the images are really there.

Want a route made for you? Our free memory palace generator places up to 20 things along 20 places in a villa, from the front gate to the dome, with a vivid image for each place, a test, a share link and a calendar reminder. It runs in your browser and nothing is stored on our side. For ready-made lists, see ten memory palace examples.

A palace for what you want to keep

The Memory Palace, the app, is not a memory trainer: you do not memorise anything with it. It is your own 3D palace for your own memories: your photos, recordings and stories each get a room you can walk through. Private by default; you invite family and friends when you choose. The free memory palace generator is a separate tool for the classic technique. The app is made by a small team in Leuven. Have a look at the app.

Sources

• Arthur Conan Doyle, A Study in Scarlet, chapter II, The Science of Deduction (the brain attic), full text at Project Gutenberg: gutenberg.org/ebooks/244
• A Study in Scarlet, first published in Beeton's Christmas Annual, December 1887, Wikipedia: en.wikipedia.org/wiki/A_Study_in_Scarlet
• Sherlock (TV series), BBC, first episode 25 July 2010, last episode 15 January 2017, Wikipedia: en.wikipedia.org/wiki/Sherlock_(TV_series)
• Method of loci (also called memory palace, journey method or mind palace technique; its use in Sherlock), Wikipedia: en.wikipedia.org/wiki/Method_of_loci
• Cicero, De oratore II, 351-354 (the story of Simonides), Latin text at The Latin Library: thelatinlibrary.com/cicero/oratore2.shtml
• Rhetorica ad Herennium, book III, 16 to 24 (rules for places and images), passages at the University of Texas at Austin: laits.utexas.edu/memoria/Ad_Herennium_Passages.html
• Maguire, Valentine, Wilding and Kapur, Routes to remembering: the brains behind superior memory, Nature Neuroscience 6 (2003), PubMed: pubmed.ncbi.nlm.nih.gov/12483214
• Dresler and others, Mnemonic training reshapes brain networks to support superior memory, Neuron 93 (2017): cell.com/neuron/fulltext/S0896-6273(17)30087-9
• Summary of the Dresler study (figures for recall before and after training), ScienceDaily, 8 March 2017: sciencedaily.com/releases/2017/03/170308131236.htm