OUT OF YOUR TINY MIND PALACES

I hope we all settled down on New Year's Day to watch Sherlock: The Abominable Bride, didn't we? We did, didn't we? Well, even if you've been trapped under something heavy and unable to click on iPlayer, you're totally familiar with Sherlock (Benedict Cuberbatch) and his "memory palace" technique for remembering absolutely everything... Really? Do we have to start from the beginning?

So, BBC's new Moffat/Gatiss adaptation of Sherlock Holmes represents the Great Detective's amazing powers of deduction as his use of a technique called a "mind palace". Sherlock goes into a sort of trance where he can access memories of just about anything he's ever read or known, making him a sort of walking Wikipedia. In His Last Vow (2014), Sherlock goes up against a villain, Charles Magnussen, who has the same ability and uses it to blackmail people with personal information. In The Abominable Bride (2015), we see Sherlock's memory palace as a sort of virtual reality, an imaginary world he can go into to solve problems.

So far, so cute. The New Years Day episode provided a rationale for giving us a Victorian caper with Watson and Holmes in period gear, which was a hoot, but it was all happening in Sherlock's head as he used his mind palace to go through an old case and solve the mystery of Moriarty's apparent return from the dead. Now, my opinion would be that the episode got way too clever for itself and collapsed under the weight of its own silliness BUT this isn't a TV review blog, it's a Psychology blog, so where's the Psychology in this?

Are there such things as mind palaces? Can you train yourself to remember absolutely anything?

It's a memory technique. It doesn't have to be an actual place. The way it works, you put information there, and theoretically you'll never forget it, you just have to find your way back to it - Sherlock

And it is a real thing, the memory palace. Only it's not really called that. It's called the "method of loci" and it was first written about by the ancient Romans. I won't say they invented it because it was probably about for centuries before them. Anyone who's read The Odyssey must have wondered how poets like Homer got to know huge poems back in the days before writing was invented. But it was the Romans who perfected the technique and the famous philosopher  Cicero describes it in his book on public speaking.

It works by getting parts of your memory that normally work separately to start cooperating: the visual memory and the semantic memory. You choose a place you know very well (such as your bedroom) or a familiar route (like your journey to work or school). The various "stops" along the way or items of furniture in your room are the "loci" in your memory palace and you visualise the things you need to remember being present there. When you need to recall them, you mentally "retrace your steps" through the room or along the route, pausing to notice each of the things you need to remember in order.

Let's take an example. Perhaps it's very important to you to remember all the kings and queens of England. There they all are, to the side. Quite a lot. We'll focus on 1066 onwards.

We kick off with two Williams and I'm thinking of the first "locus" along my route, which is my doorstep. That's easy: I'm always getting horrible bills in the post, so I imagine two Bills (= Williams) on my doorstep, one for gas and one for a credit card.

Next there's a Henry, so I need to think of a Henry at my door, someone I'll remember. Maybe comedian Lenny Henry: yes, he's here to pay my Bills with that money from Comic Relief.

There's a Stephen next and my next locus is my car that I see when I step out of the house. I need a Steve in my car, a memorable one: Stevie Wonder, since he's blind. OK, so Stevie Wonder's waiting for a lift in my car.

Mathilda comes next and my next locus is the rubbish bin at the ed of the street. The only Mathilda I can think of is that book by Roald Dahl they turned into a hit musical. She could make stuff fly, so I imagine Mathilda levitating the rubbish bin and scattering trash everywhere.

I could go on, but you get the point. Now, if I'm asked about the kings and queens of England, I start on my doorstep where there are two bills (so William I and II), then Lenny Henry helping me pay them (Henry I), then on to my car where Stevie Wonder's waiting for his lift (Stephen I) and then past the bin, which Mathilda is levitating (Empress Mathilda).

I could go on...

(There's another Henry to go next, so I think footballer Thierry Henry might be playing in the school field but - oh no! - he's being chased by a lion... that's Richard the Lion-Heart of course).

The only fiddly thing about memory palaces is building them: coming up with memorable people or things can take a bit of imagination sometimes, but the only thing that matters is that the connection makes sense to you. So if you want to remember King John coming after Richard the Lion-Heart and you once had a pet gerbil called John, then you need to imagine the lion being chased away by a gerbil. The sillier the better, because that makes it memorable.

But if a bearded American dude makes it clearer to you, have a look at this chap explaining things instead:

The Method of Locus does work and the more you use it, the easier it gets. In theory, you could build up a huge repertoire of knowledge based on the same route or room: so long as you get the starting connection right, your semantic memory will retrieve the next image in the sequence, so you won't get you kings and queens of England muddled up with your past winners of X-Factor (Steve, Shayne, Leona...).

Now you might be thinking, that's all very well, but it won't let me do the stuff that Sherlock does! Well... NO, because Sherlock is a FICTIONAL CHARACTER

But despite this, some pretty impressive feats of memory go on using the Method of Loci and similar techniques. Since the '90s, there have been Memory Competitions and the 2006 World Memory Champion, Clemens Mayer from Germany, used a 300-point-long journey through his house to recall 1040 random digits in a half hour. Gary Shang has used the method of loci to memorise pi to over 65,536 digits. Read that back to yourself. Pi, to over 65,000 digits. Now watch that scene from Life of Pi and think, somebody did better than that! The clip below shows Thomas Morton, who has memorised a great amount of pi and a telephone directory!

The point is, these are ordinary people using a memory technique (memory tecniques are called "mnemonics") to do extraordinary things. They're not extraordinary people. There are extraordinary people out there. The page on individual differences in memory has some stuff on photographic memory, people like Stephen Wiltshire who can draw a whole city from memory. The point is, these people don't use mnemonics. They have abnormal memories.

Interestingly, TV's Sherlock is presented as being on the austistic spectrum, having difficulties in relating to people around him. Stephen Wiltshire is also autistic. While not every person (or even most people) on the autistic spectrum has this sort of phenomenal memory, it's interesting that some do. These "savants" seem to gain some abilities almost as compensation for losing others.

There's a terrific documentary series called Beautiful Minds available through Youtube and the first episode, The Memory Masters, deals with these people. Here's part of that below: have a watch and be amazed.