Mastermind: How to Think Like Sherlock Holmes (5 page)

The attic can be broken down, roughly speaking, into two components: structure and contents. The attic’s structure is how our mind works: how it takes in information. How it processes that information. How it sorts it
and stores it for the future. How it may choose to integrate it or not with contents that are already in the attic space. Unlike a physical attic, the structure of the brain attic isn’t altogether fixed. It can expand, albeit not indefinitely, or it can contract, depending on how we use it (in other words, our memory and processing can become more or less effective). It can change its mode of retrieval (
How do I recover information I’ve stored?
). It can change its storage system (
How do I deposit information I’ve taken in: where will it go? how will it be marked? how will it be integrated?
). At the end, it will have to remain within certain confines—each attic, once again, is different and subject to its unique constraints—but within those confines, it can take on any number of configurations, depending on how we learn to approach it.

The attic’s contents, on the other hand, are those things that we’ve taken in from the world and that we’ve experienced in our lives. Our memories. Our past. The base of our knowledge, the information we start with every time we face a challenge. And just like a physical attic’s contents can change over time, so too does our mind attic continue to take in and discard items until the very end. As our thought process begins, the furniture of memory combines with the structure of internal habits and external circumstances to determine which item will be retrieved from storage at any given point. Guessing at the contents of a person’s attic from his outward appearance becomes one of Sherlock’s surest ways of determining who that person is and what he is capable of.

As we’ve already seen, much of the original intake is outside of our control: just like we must picture a pink elephant to realize one doesn’t exist, we can’t help but become acquainted—if only for the briefest of moments—with the workings of the solar system or the writings of Thomas Carlyle should Watson choose to mention them to us. We can, however, learn to master many aspects of our attic’s structure, throwing out junk that got in by mistake (as Holmes promises to forget Copernicus at the earliest opportunity), prioritizing those things we want to and pushing back those that we don’t, learning how to take the contours of our unique attic into account so that they don’t unduly influence us as they otherwise might.

While we may never become quite as adept as the master at divining
a man’s innermost thoughts from his exterior, in learning to understand the layout and functionality of our own brain attic we take the first step to becoming better at exploiting its features to their maximum potential—in other words, to learning how to optimize our own thought process, so that we start any given decision or action as our best, most aware selves. Our attic’s structure and contents aren’t there because we
have
to think that way, but because we’ve learned over time and with repeat practice (often unknown, but practice nevertheless) to think that way. We’ve decided, on a certain level, that mindful attention is just not worth the effort. We’ve chosen efficiency over depth. It may take just as long, but we can learn to think differently.

The basic structure may be there for good, but we can learn to alter its exact linkages and building blocks—and that alteration will actually rebuild the attic, so to speak, rewiring our neural connections as we change our habits of thought. Just as with any renovation, some of the major overhauls may take some time. You can’t just rebuild an attic in a day. But some minor changes will likely begin to appear within days—and even hours. And they will do so no matter how old your attic is and how long it has been since it’s gotten a proper cleaning. In other words, our brains can learn new skills quickly—and they can continue to do so throughout our lives, not just when we are younger. As for the contents: while some of those, too, are there to stay, we can be selective about what we keep in the future—and can learn to organize the attic so that those contents we do want are easiest to access, and those we either value less or want to avoid altogether move further into the corners. We may not come out with an altogether different attic, but we can certainly come out with one that more resembles Holmes’s.

Memory’s Furniture

The same day that Watson first learns of his new friend’s theories on deduction—all of that Niagara-from-a-drop-of-water and whatnot—he is presented with a most convincing demonstration of their power: their application to a puzzling murder. As the two men sit discussing Holmes’s article, they are interrupted by a message from Scotland Yard. Inspector
Tobias Gregson requests Holmes’s opinion on a puzzler of a case. A man has been found dead, and yet, “There had been no robbery, nor is there any evidence as to how the man met his death. There are marks of blood in the room, but there is no wound upon his person.” Gregson continues his appeal: “We are at a loss as to how he came into the empty house; indeed, the whole affair is a puzzler.” And without further ado, Holmes departs for Lauriston Gardens, Watson at his side.

Is the case as singular as all that? Gregson and his colleague, Inspector Lestrade, seem to think so. “It beats anything I have seen, and I am no chicken,” offers Lestrade. Not a clue in sight. Holmes, however, has an idea. “Of course, this blood belongs to a second individual—presumably the murderer, if murder has been committed,” he tells the two policemen. “It reminds me of the circumstances attendant on the death of Van Jansen, in Utrecht, in the year ’34. Do you remember the case, Gregson?”

Gregson confesses that he does not.

“Read it up—you really should,” offers Holmes. “There is nothing new under the sun. It has all been done before.”

Why does Holmes remember Van Jansen while Gregson does not? Presumably, both men had at one point been acquainted with the circumstances—after all, Gregson has had to train extensively for his current position—and yet the one has retained them for his use, while for the other they have evaporated into nonexistence.

It all has to do with the nature of the brain attic. Our default System Watson attic is jumbled and largely mindless. Gregson may have once known about Van Jansen but has lacked the requisite motivation and presence to retain his knowledge. Why should he care about old cases? Holmes, however, makes a conscious, motivated choice to remember cases past; one never knows when they might come in handy. In his attic, knowledge does not get lost. He has made a deliberate decision that these details matter. And that decision has, in turn, affected how and what—and when—he remembers.

Our memory is in large part the starting point for how we think, how our preferences form, and how we make decisions. It is the attic’s content that distinguishes even an otherwise identically structured mind from its neighbor’s. What Holmes means when he talks about stocking your attic
with the appropriate furniture is the need to carefully choose which experiences, which memories, which aspects of your life you want to hold on to beyond the moment when they occur. (He should know: he would not have even existed as we know him had Arthur Conan Doyle not retrieved his experiences with Dr. Joseph Bell from memory in creating his fictional detective.) He means that for a police inspector, it would be well to remember past cases, even seemingly obscure ones: aren’t they, in a sense, the most basic knowledge of his profession?

In the earliest days of research, memory was thought to be populated with so-called engrams, memory traces that were localized in specific parts of the brain. To locate one such engram—for the memory of a maze—psychologist Karl Lashley taught rats to run through a labyrinth. He then cut out various parts of their brain tissue and put them right back into the maze. Though the rats’ motor function declined and some had to hobble or crawl their way woozily through the twists and turns, the animals never altogether forgot their way, leading Lashley to conclude that there was no single location that stored a given memory. Rather, memory was widely distributed in a connected neural network—one that may look rather familiar to Holmes.

Today, it is commonly accepted that memory is divided into two systems, one short- and one long-term, and while the precise mechanisms of the systems remain theoretical, an atticlike view—albeit a very specific kind of attic—may not be far from the truth. When we see something, it is first encoded by the brain and then stored in the hippocampus—think of it as the attic’s first entry point, where you place everything before you know whether or not you will need to retrieve it. From there, the stuff that you either actively consider important or that your mind somehow decides is worth storing, based on past experience and your past directives (i.e., what you normally consider important), will be moved to a specific box within the attic, into a specific folder, in a specific compartment in the cortex—the bulk of your attic’s storage space, your long-term memory. This is called consolidation. When you need to recall a specific memory that has been stored, your mind goes to the proper file and pulls it out. Sometimes it pulls out the file next to it, too, activating the
contents of the whole box or whatever happens to be nearby—associative activation. Sometimes the file slips and by the time you get it out into the light, its contents have changed from when you first placed them inside—only you may not be aware of the change. In any case, you take a look, and you add anything that may seem newly relevant. Then you replace it in its spot in its changed form. Those steps are called retrieval and reconsolidation, respectively.

The specifics aren’t nearly as important as the broad idea. Some things get stored; some are thrown out and never reach the main attic. What’s stored is organized according to some associative system—your brain decides where a given memory might fit—but if you think you’ll be retrieving an exact replica of what you’ve stored, you’re wrong. Contents shift, change, and re-form with every shake of the box where they are stored. Put in your favorite book from childhood, and if you’re not careful, the next time you retrieve it there may be water damage to the picture you so wanted to see. Throw a few photo albums up there, and the pictures may get mixed together so that the images from one trip merge with those from another one altogether. Reach for an object more often, and it doesn’t gather dust. It stays on top, fresh and ready for your next touch (though who knows what it may take with it on its next trip out). Leave it untouched, and it retreats further and further into a heap—but it can be dislodged by a sudden movement in its vicinity. Forget about something for long enough, and by the time you go to look for it, it may be lost beyond your reach—still there, to be sure, but at the bottom of a box in a dark corner where you aren’t likely to ever again find it.

To cultivate our knowledge actively, we need to realize that items are being pushed into our attic space at every opportunity. In our default state, we don’t often pay attention to them unless some aspect draws our attention—but that doesn’t mean they haven’t found their way into our attic all the same. They sneak in if we’re not careful, if we just passively take in information and don’t make a conscious effort to control our attention (something we’ll learn about a bit further on)—especially if they are things that somehow pique our attention naturally: topics of general interest; things we can’t help but notice; things that raise some emotion in us; or things that capture us by some aspect of novelty or note.

It is all too easy to let the world come unfiltered into your attic space, populating it with whatever inputs may come its way or whatever naturally captures your attention by virtue of its interest or immediate relevance to you. When we’re in our default System Watson mode, we don’t “choose” which memories to store. They just kind of store themselves—or they don’t, as the case may be. Have you ever found yourself reliving a memory with a friend—that time you both ordered the ice cream sundae instead of lunch and then spent the afternoon walking around the town center and people-watching by the river—only to find that the friend has no idea what you’re talking about?
It must have been someone else
, he says.
Not me. I’m not a sundae type of guy
. Only, you know it was him. Conversely, have you ever been on the receiving end of that story, having someone recount an experience or event or moment that you simply have no recollection of? And you can bet that that someone is just as certain as you were that it happened just the way he recalls.

But that, warns Holmes, is a dangerous policy. Before you know it, your mind will be filled with so much useless junk that even the information that happened to be useful is buried so deeply and is so inaccessible that it might as well not even be there. It’s important to keep one thing in mind: we know only what we can remember at any given point. In other words, no amount of knowledge will save us if we can’t recall it at the moment we need it. It doesn’t matter if the modern Holmes knows anything about astronomy if he can’t remember the timing of the asteroid that appears in a certain painting at the crucial moment. A boy will die and Benedict Cumberbatch will upset our expectations. It doesn’t matter if Gregson once knew of Van Jansen and all his Utrecht adventures. If he can’t remember them at Lauriston Gardens, they do him no good whatsoever.

When we try to recall something, we won’t be able to do so if there is too much piled up in the way. Instead, competing memories will vie for our attention. I may try to remember that crucial asteroid and think instead of an evening where I saw a shooting star or what my astronomy professor was wearing when she first lectured to us about comets. It all depends on how well organized my attic is—how I encoded the memory to begin with, what cues are prompting its retrieval now, how methodical
and organized my thought process is from start to finish. I may have stored something in my attic, but whether or not I have done so accurately and in a way that can be accessed in a timely fashion is another question altogether. It’s not as simple as getting one discrete item out whenever I want it just because I once stuffed it up there.