5. Spatial memory and the memory palace

You're listening to memory booster, aHimalaya learning audio course. Be sure to check out all of the other exclusivecourses in the Himalaya app or on himalaya.com. I need to go to my mind others.He's not really doing much talking for a while.

[00:00:28] Um,

[00:00:32] Hi, I'm ed Allard. And this ismemory booster in this show. You'll hear from memory experts at leadinguniversities, from Harvard to Columbia and many more. I'll talk to them aboutdifferent kinds of memory, along with some other fascinating topics. I'mcurious about at the end of every episode, we'll review a trick technique orexercise you can use to make your memory work for you.

[00:00:58] Today on memory booster, we'regetting spatial so far. We've learned about the three main categories ofmemory, working memory, episodic memory and semantic memory. But now it's timeto get specific. I have a lot of questions about different memory, topics andtechniques I've heard about from movies and TV pop culture or the internet.

[00:01:21] Many of us have seen someiteration of Sherlock Holmes. We've watched the iconic character dive into hismythical memory palace to find some key information he stored away. ButSherlock Holmes is just a character and his memory palace has to be part of thefiction, right? It turns out the memory palace technique is completely real anddates back thousands of years to the ancient Greeks, it draws on our spatialmemory.

[00:01:46] Or our ability to remember andpicture certain surroundings. At the end of this episode, I talked to a worldchampion memory expert who shows us how to start building a memory palace ofour very own stay tuned for that. Before we start scouting out the land for ourmental construction site, I reached out to another expert memory researcher tolearn about the science of spatial memory.

[00:02:09] My name is Chris Baldus Sono.I'm an assistant professor at Columbia university. Uh, I studied cognitiveneuroscience, uh, which means that I'm interested in how the human brain canunderstand and remember the things that happen in our everyday lives. Chrisstudies, the interplay of semantic and episodic memory.

[00:02:25] He's also proposing a lot ofupcoming research to study the memory palace technique and compare subjects,spatial memories. Before we get to any of that. What does spatial memory mean?Exactly. And how does it relate to the parts of the brain and types of memorywe've already learned about the memory? Uh, if we're talking about memory of spaces,so our memory for maps of the world, for places that we live, places that wetravel, these kinds of memories we think are probably distributed in a lot ofplaces in the brain.

[00:02:54] So it's spatial memory. Um, onthe one hand could mean. This kind of semantic memory of, you know, forexample, remembering what the layout of your house looks like. You're notremembering a specific thing about your house or a specific thing that happenedthere. You're just remembering this kind of map in your mind.

[00:03:10] And so there's been a lot ofresearch really since the seventies and before about trying to understand howeither rodents or. Primates or humans can build these kinds of maps of theirenvironments. And at least traditionally the brain region that people thoughtwas most implicated is the hippocampus.

[00:03:27] And we know that if you recordfrom neurons and they at the campus, there are some neurons there that fire,when you're at particular places in your environment, People thought that thehippocampus was serving as this kind of GPS system for where you are in theenvironment and the cells can even fire.

[00:03:43] Uh, even if a rat is notphysically in the environment, if it's thinking about amaze, it's been in thosecells will also fire. And so we know that the hippocampus is doing somethingrelated to these kinds of spatial maps, but we also think that over time, thesekind of maps that you're building up from experiences.

[00:04:00] Do you eventually get, getgeneralized into a kind of semantic knowledge about your environment and whatpatients tend to be next to each other and your environment. And so over time,these memories involve not just the hippie campus, but other parts of thebrain. And one of these regions is the medial prefrontal cortex.

[00:04:17] So this is the part of your. Uh,brain that's like right behind the middle of your forehead. What we know isthat over time information from the hippocampus builds up these maps in medial,prefrontal cortex as well. And so my, uh, at least some of my projects in mylab are really focused specifically on this medial prefrontal cortex, um, abouthow we can build up maps of the world.

[00:04:38] There's another kind of spatialmemory, which is memory for. Things that are happening in spatial locations.Right? So this is not just the map, but I want to remember that a specificevent happened at a specific place. And so here we think again, the hippocampusis really important that you need to bind together this map, which is your keyit's that this is a kind of general semantic memory of the world with thisparticular event that's happening at this some spot on this map.

[00:05:04] Right. And so that, that bindingprocess, um, Is also what we might think of as spatial memory, right? This ismemory for events that are occurring at a particular place. And so we need totie together that this particular item, this particular event with the locationon this map, on this general map that we can reuse for multiple experiences.

[00:05:24] To be clear, your spatial memorycan involve both your episodic and your semantic memories. When you'reremembering the space you were in during a particular event and conjuring aspecific memory. That's episodic over time after you've built a mental map andyou pull it back up in your brain to imagine it that's semantic memory.

[00:05:44] Like we learned last episode,these things are constantly playing off each other in complicated ways. Thereisn't necessarily a clear line between one and the other. Chris blew my mind byrevealing that this isn't the only kind of mental map though. Spatial maps areprobably one of the most important kinds of maps that we have of the world, butthere could be other kinds of maps as well.

[00:06:05] So things like I mentioned aboutevents, scripts, this can be another kind of map that's about how things unfoldin time. Um, we're also doing some other experiments where we have peoplelisten to poetry that. Proceeds through specific sequences of topics and peoplecan also build maps about what the topics of these poetry of this poetry is.

[00:06:24] And so we think that this iskind of a general property of the brain that you can build up these maps of theworld. Um, and that these maps are really important for building up memories ofyour ex. Does this mapping use the same parts of the brain as. Like rememberinga map of my house. For example, that's an excellent question that we don't knowthe answer to yet.

[00:06:43] My hypothesis is that it is verysimilar, perhaps the same exact regions or at least highly overlapping regions.So there's been some work on this of trying to think about these more abstractspaces. Social networks is another kind of map people could think about. Right?You could think about which people are close together or far apart in yoursocial network.

[00:07:03] And we know that it rely to someextent on. On similar brain regions, it's still an open topic of debate,whether there's specific parts of the brain, for example, parts of thehippocampus that are really just only about physical space and don't generalizeto these abstract spaces, but this might be a kind of general property of thebrain that we try to build these filing systems for our memories and this.

[00:07:25] Uh, spatial memory is a greatfiling system for lots of things that happened to us, but we could use otherkinds of filing systems as well, that still have this kind of map, likeproperty, where we could think about kind of navigating them or think aboutrelationships between items and things. All right.

[00:07:41] It's time to move on to thetechnique that brought us here in the first place, the memory palace, what isit? So the memory palace technique, which is also called the method of flow PSIis a kind of strategy for trying to remember information. And what it relies onis having some kind of spatial map that you've memorized ahead of time.

[00:07:59] And most people use somethinglike their house or their workplace or somewhere where they spent a lot oftime. And what you do is you take the things you want to remember. And yousomehow visualize them being at locations in this well learn map. Um, there'slots of strategies for how you do this. It depends on the kind of thing you'retrying to remember, but the idea is that once you've imagined this in yourmind, that later on, if you want to remember this information, all you need todo is mentally walk back through this memory palace.

[00:08:26] So, if you imagine yourselfwalking back through this same map, then you can just kind of look around to seewhat items are there in your memory palace. And this, this is a very oldtechnique that dates from ancient Greece for trying to remember, for example,long speeches, and it's been refined over time.

[00:08:42] But the basic idea that hasreally remained the same ever since I'm assuming that this draws on the sameparts of the brain and sort of takes the same effort, even if you're likeadding something. Into an environment of your house that you've never actuallyseen there or experienced there. My instinct tells me that it's.

[00:09:02] Sort of the same principle asjust remembering, walking through your house. Is that true? That's right. Soyeah, how this actually works in the brain is something that's very interestingto me. So while I was still working at Princeton, we actually collected somepilot data on one of these memory athletes.

[00:09:18] And so we had him go throughthis method of low side process. So we had him. Um, think about the locationsin his map. The map he was using was from an athletic field where his kids usedto spend a lot of time having sports practices. And so he could go throughthese locations in his map, we could give him two digit numbers and he couldencode the two digit numbers into objects.

[00:09:37] He has a system for convertingthese numbers into objects, which is which many of these mental athletes use.Then he can imagine these objects at these locations in the athletic field. Andthen, uh, later on, uh, minutes or days later, or we could ask him. Tore-imagine walking back through this field and the items would just serveimmediately, come to mind for him.

[00:09:58] And again, there's a lot ofstrategy and how you do this. So for example, you want to make the imageryreally vivid. You want the thing that you're imagining to be sort of moving andhave as many features as you can. Ideally, you also want it to be interactingwith the environment in some way that will help.

[00:10:13] Find those memories together.So, so for example, if he's, um, imagining one of the locations on the field asthe bleachers. And so if he's imagining, if the item is trying to remember as acar, you might imagine that car being smashed through the bleachers, right? Andth the bleachers are all twisted from the teat and the car is smoking, right?

[00:10:32] There's, there's someinteraction between these items. So now when he goes back and thinks about thebleachers. So remember that that car is stuck in there. Exactly how this isworking in the brain is again, something we're super interested in. Um, we'reactually hoping to do a much larger scale experiment with this, and we'recurrently applying for funding to do that.

[00:10:50] But our hypothesis is thatwhat's going on is that these well-learned maps are living somewhere insemantic memory. So maybe in immediate prefrontal cortex, uh, there might beother parts of the brain that are involved in story these maps as well. Andthen what these people are really good at doing is very rapidly.

[00:11:08] Binding some item. They'retrying to remember, uh, binding it to a location on the spatial map. And again,we think the hippocampus is critical, critical for that kind of binding. Andthen later on, when they want to remember something, they reactivate this map.And what that does is activates a PA pattern completion process in the brain.

[00:11:24] By remembering the map, thebrain through the hippocampus can automatically bring online. What was themissing piece of that memory? What was the item that's in that memory? And sothe critical thing here is that these maps are really acting as a good way as akind of filing system, as a way to develop cues that you can use to jog yourmemory.

[00:11:43] Uh, the biggest problem withremembering lots of things. It's not really a capacity problem. Um, our braincan remember tons and tons of things. The problem is finding those memorieslater on. And so having this map gives you a way to find these memories lateron. It gives you a way to, um, to figure out a piece of this memory that youcan use to remember the whole memory.

[00:12:01] I remember in previous episodeswhen we talked about the importance of association, well, here it is, again, inepisode three, for example, we talked about how the pegword method forces yourbrain to associate a list of items with an image you prepared ahead of time.This makes it easier to conjure those memories.

[00:12:22] This is the same principle thatsaid Sherlock Holmes. This technique's most famous fictional user is a genius.Do you need to be a genius to make this technique useful? Are some peoplebetter than others at using their spatial memory? Chris had an answer. That's agreat question about how much variation is there is among people.

[00:12:39] So there's actually this reallycool project called sea hero quest there's there was a paper in current biologyin 2018 that gave some of the preliminary results from this, but it was a gamethat they had many, many people play since it was a game, you could get lotsand lots of people to play it way more than we usually would get in anexperiments.

[00:12:57] I think it was over 2 millionpeople that played this game and part of the game involved spatial memory. Soyou'd have to. Um, do things like, remember you're, you're steering this littleboat around and you have to remember where you've been and how you could getback to places you've been. And so there's definitely a lot of variation amongpeople and how good their spatial memory is.

[00:13:15] It's not really clear if this issomething that's biological. It definitely has a lot to do with the culture inwhich people grow up. So for example, countries that involve a lot of drivingcountries where. People often have to navigate, uh, via driving, um, tend tohave much better spatial memory. There are gender differences that men tend tobe a bit better at most of these spatial memory tests and women, but thatdifference is much smaller in countries where there's less gender inequality.

[00:13:40] And so it's also, again, unclearif this is a biological thing or a cultural thing. There's also big ageeffects. So, um, in general, younger people, um, tend to be much, much betterat this basically every year that you are older than age 20, you're probablygetting worse at spatial memory. And it's also looked at as a potentialbiomarker for things like Alzheimer and other kinds of dementia.

[00:14:02] I assume then, you know, thedifferent aptitude for employing spatial memory. Can also impact people'sability to use the memory palace technique. That's right. So this is alsosomething that we're hoping to do, which is, um, enroll a number of collegestudents that haven't used this technique before and look at how theirperformance improves over time.

[00:14:23] As they're learning this, thistechnique, um, and look at how their brain activity changes over time. Asthey're learning this technique. It does seem like in general, you don't needto be, have a special brain of any kind to be good at this. That's at leastwhat most of these mental athletes report is that they didn't have particularlygood memory.

[00:14:40] And in fact, they still don'thave particularly good memory if they don't choose to use this strategyactively. So if I'm right, if someone is just talking to them and they're notusing this strategy, they don't have any better memory than, than anyone else.And so it seems like this is something that is quite trainable.

[00:14:56] Um, I'm sure there are alsoindividual differences in how effectively people can use it, but it seems likethis is probably something that most people could do. If they choose to usethis strategy, they could really improve their memory. Hold on. Did Chris justmention improving your spatial memory? Can you improve your spatial memory?

[00:15:15] Only can. So, yeah, like Imentioned with Vudu games, those video games are maybe not intendedspecifically as facial memory training, but they do seem to provide that tosome extent. I mentioned also about. Uh, like countries where people spend alot of time navigating on roads. Those people also tend to have much betterspatial memory.

[00:15:32] There also have potentiallybeen, uh, people who have thought about developing interventions for olderadults that tend to have declining spatial memory. Are there ways that wecould. Help them, um, by continuing to train, continuing to exercise thesespatial memory muscles, could we potentially slow or, or halts this spatialmemory decline in older people?

[00:15:53] As far as I know that we don'thave an exact way of doing that yet, but it certainly seems possible that ifyou're using these spatial memory systems, we do have evidence that that canimprove your memory over time. In episode one, Dr. Daniel Schacter said thejury was still out on whether memory as a whole could be improved or built uplike a muscle.

[00:16:13] Those some taxi drivers inLondon exhibited larger or more developed memory regions of the brain as aresult of their constant use of memory. It's hard to say whether that meantthey would be better at remembering all things in a general sense, though. Wecan't say for sure yet, Dr. Schachter ultimately landed on the fact.

[00:16:31] It's unlikely that memory as awhole can be improved by just using your memory more often. I presented thisperspective to Chris and gave him the opportunity to respond. Yeah, I, this,this whole field of cognitive training, which is usually sort of targeted atolder adults, but, um, it's targeted at many people is, is quite controversial.

[00:16:51] And there's a lot of questionsabout the extent to which. Training on some of these tasks. So if you play oneof these, uh, these cognitive training games, for example, you'll definitelyget better at that particular game, but does it really help you more, moregenerally? Right. So if you're trying to practice remembering a list of words,is that going to help you remember where your car keys are or things like that?

[00:17:12] And so in general, these testsusually don't show great. What we call transfer effects, meaning thatpracticing one kind of task is going to help you on other related tasks. Weprobably don't know the extent to which this is true for spatial memory. As Isaid, we really, these are not well controlled studies.

[00:17:27] The things that we're doing, thesea hero quest things, they're just looking at correlations between aspects ofpeople's environment. Yeah. Their spatial memory capabilities. It could be thatthere's critical periods for this so that it could be that when you're young.Um, so maybe, you know, younger than 20, the amount of spatial navigating your.

[00:17:44] Doing does have a big impact andmaybe it doesn't later in life, it could be that you really need to practice.Yes, very similar kinds of spatial memory tasks. So if you're, uh, if your goalis to be able to do a good job walking around the park, you really need topractice walking around parks and maybe driving, uh, right.

[00:18:03] And navigating on roads is notgoing to help you. So, you know, when it gets down to practical questions, howto improve a specific task, um, it can be a bit, bit tricky to know what'sgoing to help. So, what did we learn so far? Well, spatial memory is our mentalmap of the spaces we've been in that can include our memory of spaces andspecific events that we experienced in those spaces, which would fall under theumbrella of episodic memory or spatial memory can include the general mentalmap.

[00:18:31] We've built up of a place aftervisiting it many times. That would fall under the umbrella of semantic memory.There are actually other kinds of maps to poems that flow from topic to topicare like mental maps. Since our brain tries to process the steps from one partto another, in a similar way, the jury is still out on whether we can improveour memory as a whole, by just using it.

[00:18:52] That said there is evidence thatculture upbringing or interests like video games can impact your aptitude forspatial memory tests. Maybe this means we can improve spatial memoryspecifically. At the very least, it means we can improve our performance for aparticular memory task with practice. That brings us to the memory palacetechnique also called the method of low PSI.

[00:19:15] I just had to try this formyself. So I turned to another memory athlete to show me how it's done. Yeah.My name is Yanis. Milo. Thank you for inviting me today. I'm from Germany and Iam yeah. A memory athletes. So I am going to competitions about memorycompeting against each other. Yeah. That's uh, that's me.

[00:19:35] Johann is one of a variety ofchampionships and countries throughout Europe. He first won the worldchampionship in 2012 and he was ranked number one in the world for fiveconsecutive years until 2017. He first competed in 2004. After he saw a memorycoach on TV, he was instantly hooked. I have a muscle disease.

[00:19:58] It's called F S H D. And thatmeans that my muscles go down over time. And when I was. The 14, they, um, Iwas diagnosed with that and then it started to begin, came, become worse. And Iwas, it was hard for me to walk and to run and to play table tennis, which was,uh, they called me for me. And, uh, at this point it was very tough for me toget upstairs and so on.

[00:20:24] And I couldn't do any physicalsport any more, but then. Memory sports come into my life. And it reallymotivated me to be able to compete against others, uh, around the world on ahigh level is one, one thing. What really helped me to overcome all thesemental problems, which I faced because of this muscle disease center in 2012, Iwon the world memory championships, and that was really, really cool.

[00:20:56] Johann has explained the processof using the memory palace in his own words. What's his palace, his apartmentI'm thinking about, okay, there's my entrance door to my apartment. Then I,this is a point that location number one, then I go in and on the left, thereis a little board with shoes. So a shoe board as number two, and then a then asa chair, And the chair would be number three.

[00:21:19] So I would go like a round tripthrough my apartment and maybe have something like 20 or 30 or. Uh, if you havea big house, you can even have 100 locations in your, your house. And, um, youhave that as your tool because you need to prepare that before. So when I'm ina competition, I have a set of predefined journeys.

[00:21:44] I call them journeys. So onewalk through my one winter walk is a journey in my apartment, for example. So Ihave a set of that. And then I have to memorize a funny, simple words, thedisciplined words. And then I connect these words, which I was, which I have tomemorize with the locations. So let's say you have the first two words.

[00:22:04] It could be chocolate and beer,for example. So I'm mentally standing in front of my apartment to war. And Isee the door is made of chocolate. Very delicious. So I'm, yeah, I'm getting abit hungry and biting myself through the, um, through the door, eating all thechocolate and then I'm so Searcy that I drink a beer, so I memorized chocolateand beer at the front door.

[00:22:31] And then I go to the nextlocation, the next location of the shoe board. And let's say you have tomemorize your banana. And so photograph. So I would see in my shoes, everyshoe, every shoe, there's a banana inside and then take some photographsbecause it's so funny. And then I go to the chair, the third location, andthere might be, um, what could it be?

[00:22:55] A plant and the bicycle. So Isee on my chair, a plant growing, and there are little bicycles on the plant.So. Picking one bicycle and, uh, yeah, driving into my apartment, somethinglike that. And this is just three locations. And if you want to memorize 100words, for example, you will need 50 locations with this strategy because Ialways put two images on a location here and EDI, I'm pretty sure that youalready memorized my six words here.

[00:23:26] Let's see. Did you memorize theword? Johan is listed helped along by his story. Pause the show and try to saythe list in order again, how'd you do? Here's the list again? Chocolate beer,banana photograph, plant bicycle. I was surprised how his story helped meremember his list, even though I wasn't even familiar with the actual layout ofhis memory palace.

[00:23:51] Imagine how much easier it wouldbe in your own house or apartment. So what's the first thing you do when you'retrying to adapt your house or apartment into a memory palace? I would suggestthat I recommend that you really, that the listeners really start in their ownapartment because they are known that we know that very well.

[00:24:09] And then they would create awalk, a mental walk of let's say, 20 locations. It's it's not too much for thebeginning and it's, but it's not too, too less. So. It's very easy for everyoneto do because you know your apartment very well. And then you really do aroundfor three, three apartment. Like I did it.

[00:24:28] So front door, then you lookwhat is left to the front door. And then you go to the next, what comes then?What comes then? And then you create 20 locations, write them down and try toreproduce you and recall them in your mind without looking. And as soon asyou're capable of doing that, and that just takes.

[00:24:47] Not that long five minutes, 10minutes. It's really possible. Then you would start maybe with memorizing ashopping list, like, uh, yeah, like banana again, like milk sober or whatever,and try to connect. Not like I did it with two words on a location, because Ithink that's a bit more, um, developed, just put a button image from yourshopping list.

[00:25:11] On one location, so sugar at yourfront door. So you're think about there's a front door is full of sugar andthen the next location, there's a milk MOOCs spreading everywhere. And itsmells really, really bad already. And it's old milk and so on. So you willjust memorize the shopping list was 20 items, but even this for actually not sodifficult.

[00:25:34] Task will give you an very, verygood insight in how good these techniques work. And then you can start buildingon that building more locations starting was 20 it's nice. But then you go upto 50, maybe 100. And for example, I have in my head 2,500 locations and whichI can use every time, anytime. So yeah, that's not the goal for maybe foreveryone out there, but having.

[00:26:01] At least 24 at the beginning andbuilding up to 100, that's possible for everyone. Take a while. Walk aroundyour home, starting at your front door and choose 20 locations as Johan isdirected. After you have the locations memorized visually you can try a shortexercise, like the one Johan has directed earlier.

[00:26:21] Can you remember just a fewitems using your memory palace? I'll give you a list of just 10 words and we'llsee how many you can remember using this technique. Don't write these down,just listen and visualize each word in each location of your memory. Palace.Ready? Okay. Wood soup book steak, phone radio.

[00:26:54] Knife car candle, cookie. Okay.Now start back at the beginning in your house apartment or wherever else youchose your memory palace to be. Walk back through and try to remember the wordsat the 10 locations. It might help to write them down as you go. So you canremember how many you got. Pause the show now and test yourself.

[00:27:24] How'd you do? Here's the listagain? Would soup. Book steak phone, radio knife, car candle, cookie. Did thepalace method worked for you? Did it work better than the pegword method? Fromepisode three, you can continue practicing with your memory palace by workingyour way up to memorizing 20 items with the 20 locations you identified, then youcan start finding two words to each location, to double the number of words youmemorize with the same spot.

[00:27:55] Eventually you can use yourmemory palace to remember all kinds of things, not just a grocery list. Theancient Greeks would associate each location in their memory palace withdifferent parts of monologues and speeches. They had to give that way. They'dwalk through their house and remember what to say next, pretty wild.

[00:28:11] Right? Next time, a memorybooster. We'll be moving from spaces to images and talking about another memoryconcept that has entered pop culture, photographic memory. I talked to you then

[00:28:27] what you just heard was memorybooster, uh, Himalaya learning audio course. Be sure to check out all of theother exclusive courses in the Himalaya app or on himalaya.com.