Wednesday, July 20, 2011


The Tourist asked: Old-timer, can you tell me how to get to St. Johnsbury from here?

Eben Jenkins thought a bit, raised one hand and started to gesture up the Mountain Road. Thinking better of it, he stroked his chin and then pointed back down the River Road and almost spoke. He caught himself, looked the other way - up the River Road, and his eyes took on a faraway look. "Young fellah, you can't get theah from heah."

Some overview, before putting you on to some of the research.

Wayfinding is a subtopic under spatial memory. Though wayfinding can involve different scales of routes to follow, these are not vastly different scales. They are human sized, and involve moving a human-sized body, or objects only slightly smaller or larger. This is what human beings have navigated in for millennia. We now scale up to spatial relationships a million X larger or million X smaller, but these are recently learned. Like the Fahrenheit Scale that works best in the nice, human-living numbers 0-100, wayfinding is the understanding of movement from room-to-room, of walks in The Shire. Longer journeys of even ten miles begin to require a greater level of abstraction. This is landmark navigation, we have a hundred brain mechanisms we are unaware of helping us out, it is what we are built for, and it is far superior on the human scale. Even switching between scales at this level is not that hard.

Longer journeys, especially those which have to navigate around something large, such as a lake or a mountain range, push our brains to do either of two difficult things: either we must create a long chain of directions or we must develop a set of abstracts which allow us to store the navigational information in shorter, but more complex form. Some humans do one, some the other. Both require working memory and set-shifting, but the former is emphasised in landmark, or egocentric navigation, while the latter is more in play in cardinal/overhead or allocentric navigation. The hippocampus and prefrontal cortext you've heard of - those are key to egocentric navigation. Other cortical areas that you haven't heard much about* are key to the allocentric navigation. Allocentric seems to be later, more advanced, dependent on parts of the brain other than the most basic. That is a ridiculous oversimplification, but I think it holds.

In either event, memory storage and retrieval have to be in fine working order.

Interesting tidbit #1. Some tests of wayfinding abilities on the pencil and paper scale give a very accurate picture of how you will do walking around indoors or in a small neighborhood. Others tests give an accurate picture of how you will do on journey-length navigation of miles. For the in-between scales - from the large mall to the town - the results are ambiguous. Both types of test will stretch so far and no farther in the individual, whether scaling up or scaling down - and the stretch is a bit different for each person. The tests don't tell us much, because they begin to measure two separate things. People switch sets of scale and of method at the margins, and the tests measure something else: general intelligence, which is related to our ability to switch sets.

Interesting tidbit #2. OTOH, they tell us a lot about people who can't navigate at all. An experiment by Toru Ishikawa (and that name will show up again in later posts) showed that some students learned a route right away, others learned it gradually, and some never learned it, even after ten repetitions.

Interesting tidbit #3. (Also Ishikawa) Using a GPS interfered with people's ability to learn a route. All my map-loving readers are secretly rejoicing, but there could be problems with this study. The participants may have not been that familiar with using GPS, and relatedly, switching scales on the small screen may have thrown them off. (This was a walking test.)

There is a further possibility suggested by this. Those who rely on abstract, allocentric, overhead map navigation may not develop their landmark, egocentric navigation as fully as those who rely on it entirely. The prideful allocentrics who can navigate to Spain and back may forever be less good at getting about town than the egocentrics. The good egocentrics, that is. Obviously, everyone is better than those who haven't got a clue. Of which there are many.

Tangential humorous story about a guy who didn't have a clue. A family in a car with out-of-state plates rolled down the window. The husband, driving, asked where the cliff with all the faces were. I started to tell him where the Old Man of the Mountain was - about two hours away, but he cut me off. "No, I don't mean the Old Man of the Mountain! I mean the place where they have the faces on the cliff!" I noticed that his wife was rolling her eyes, the children in the back looking very quiet. This discussion had apparently been going on awhile before they had gotten to me.

Inside, I'm thinking Dear God, don't let him be talking about Mount Rushmore. I don't think I can break it to a guy this angry. Aloud, I said gently, "Well, there are a few others up in that direction, there's Indian Cliff, it's got a staircase observatory..."

"No, these weren't Indians."

"Well, we don't have anything as fancy or impressive as Mount Rushmore here in NH that I can think of..." I said tentatively.

"No, it's not goddam Mount Rushmore either! It's a cliff with faces on it!"

"Sorry, I've lived here most of my life, but I'm not sure what you're describing."

He rolled up the window and drove off. He waited at the stop sign a long while - I think they were arguing still - then took an emphatic left and sped through town. Left was not the direction for either Franconia or South Dakota. But you knew that.

*entorhinal and posterior parietal


Sponge-headed ScienceMan said...

One of my favorites for directions is driving in a city I’m not too familiar with (as on a first time business trip) with the radio on headed to my morning meeting. The traffic reporter then informs me that things are really a mess at the Spaghetti Bowl this morning and I should avoid that area at all cost. Using the local nickname for a particular area or highway feature does this out-of-towner no good at all. I could be heading right into the Spaghetti Bowl for all I know. I’ve found that cussin’ at the traffic reporter is no help, BTW.

Sam L. said...

I suspect you'd have had some idea if he had a name for that cliff.

A friend of mine grew up in St. Louis, MO, and moved back after 20+ years away. People, knowing him to be a local, gave directions by landmarks--many of which were built after he left. Unhelpful.

I'm a map guy, but can do some landmarks.