Philly, Back Again

I'm late with this post, but the few days since my return from Philly have been crazy, so I'm just getting to it. I spent my second day with the navigation researchers taking part in a truncated version of an experiment they've been running to test if and how people of differing navigational abilities improve on a wayfinding task over time.

We traveled to a satellite campus of Temple University about 50 miles north of Philly early last Thursday morning. Once there, I waited by the car while the researchers, Victor Schinazi of Penn and Dan Nardi of Temple, went off to set things up. They returned with a wheelchair, a blindfold, and a portable radio with headphones. All of it was for me--once in the chair, blindfolded, and oblivious to all sound but the grunge rock radio station, I was wheeled in circles to disorient me and then pushed through the campus. I was released at the starting point of "route one," a fairly short, albeit circuitous path (about two tenths of a mile, I'd guess) connecting four buildings that I was told to learn as we walked. I was then summoned back into my dark, Nirvana-fueled wheelchair, spun in circles again, then pushed to another part of campus where we arrived a few minutes later to walk "route two."

After that, it was back into the dark, Alice in Chains, more spinning, and a return to route one. This time, at each building, Victor and Dan told me to point to every other building in this route and in the unseen route two, and they checked my pointing with an electronic compass. My pointing had to be stiff armed and straight-fingered (Grim Reaperish) to ensure an accurate compass reading. I have no idea what the groups of passing students thought of our little group, but I'll never forget the looks as I arose from my wheelchair and began pointing (seemingly) at several of them.

Ok, so, then: dark, Soundgarden, spinning, route two, and the same walking and pointing task. After all this, I was wheeled back to a mystery room and asked to close my eyes and pretend I was walking both routes, pointing all the while. Finally, a very long questionnaire that asked me to judge the distances between all the buildings in each route.

After lunch, we started phase two (which in the normal experiment would happen a week later). Victor and Dan showed me a curving connector path between the two routes. Then we did all the rolling, spinning, pointing stuff again at both routes, the imaginary route pointing, and the questionnaire. Normal subjects would return for a third go-round, at which time they would be shown a second connecting route. Another part of the research I skipped due to time constraints is the follow-up fMRI.

Anyway, the point of all this is to see if and how people improve from one trial to the next. It builds on a very similar experiment conducted a few years ago by Daniel Montello and Toru Ishikawa who found that subjects broke into three groups--some improved steadily, but "most participants either manifested accurate metric knowledge from the first session or never manifested accurate metric knowledge." In other words, their findings indicated that for the majority of us, when it comes to navigational acumen, you either got it or you don't. 

Victor and Dan screened their subjects to make sure they have never been to this campus and promise to refrain from investigating it independently. And in the first trial, navigation performance is all over the place. Some people are weirdly, shockingly accurate with their pointing and distance estimations. Others make errors that defy basic logic. In deference to their yet-to-be-published data, I won't reveal more about what Dan and Victor have found. But I will as soon as everything is in press and I have the chance to get their comparative analysis of my own pointing performance.

My mind hurts

This is going to be a short post. I need to write it, but I have the brain power of a turnip right now, so I won't go into detail. I've just returned from a 9-hour day of navigation testing at the University of Pennsylvania. Fittingly, the day began with me marching seven blocks in the wrong direction while trying to walk from my bed-and-breakfast to Penn's Center for Cognitive Neuroscience

Still, after I found the place and met my gracious researcher hosts, I tested quite well. I spent a very long time learning my way around eight virtual cities in two different experiments and then took my turn in the MRI. I had imagined an MRI to sound like a photocopy machine, whirring reassuringly as it scanned the brain. It's actually a little like being trapped under the hood of a car when the alarm is blaring. On the plus side, I was able to see a few of the scans immediately afterward, giving me the first piece of hard evidence on this odyssey: I do in fact have a brain.

Another day of testing tomorrow, but thankfully most of it is outdoors. No computers. No floating through the fantastic, virtual ghost towns. No super-charged magnetic sarcophagus.

I'll supply more detail on my lab-rat day and get into the science of all this soon.

Testing 1,2,3

In a few days, I leave for Philadelphia where some navigation researchers from the University of Pennsylvania and Temple University will do their best to diagnose my sense of direction. The tricky part is that most labs investigating human wayfinding aren't set up to evaluate individuals. They focus on how the mind reacts to certain navigational cues, what brain areas are activated, and what benefits or impedes our spatial ability generally, and research into the how and why of individual sense-of-direction differences is in its infancy.

But these folks in Philly have agreed to run various tests on me (some real-world navigation, a bit of virtual reality, some paper and pencil stuff, and an fMRI) and to compare my performance and my brain activation to the rest of their study subjects. I also have more lab-rat dates lined up for later this spring. Can't wait.

Is GPS killing your brain?

I called up Toru Ishikawa, a navigation researcher at the University of Tokyo, last night (the next morning for him). We talked about his research into how GPS affects our ability to learn our way around a new place. Two years ago, he had about 60 men and women learn a short route through a residential suburb of Tokyo--one third with no navigational aid, one third with paper maps, and one third with GPS. Then he tested them (asked them to travel the route independently and timed them, had them point from their destination back to where they started the journey, had them draw sketch maps of the route, etc). On almost every metric, those who learned au naturale kicked ass. In the test phase, they navigated the route faster and more efficiently (fewer wrong turns), drew more accurate maps, and later rated the task easier than those who used GPS. The map users couldn't match them either, although they did better than the GPS group on many of the scores.

What's this mean? It could be evidence that GPS is melting our brains and we should all stop using them before we turn into zombies who can get from here to there but have no idea where here or there is (or anything in between). There have been similar questions about how the Web (specifically Google) may be changing how we think (and not for the better). But let me venture to say that these experiments are not going to spark any such cultural backlash. There are too many people who love the convenience of these gizmos, and others who would never venture out of the house without them.

So, maybe GPS navigation systems should just be designed differently--possibly using a variety of graphics or voice commands--something that might reinforce our navigational synapses rather than short-circuiting them. Or maybe, GPS will be whatever it will be and this type of research will simply document its neurological impact and provide more evidence that every navigational aid we've introduced over the millennia (from big buildings to street signs to Google Maps) has permanently eroded our innate wayfinding abilities. This idea, of course, raises the question of whether this is an evolutionary change, some permanent rewiring of our brains, or if we could resurrect those abilities with "training."

Personally, I've never used a GPS and I'm in no hurry to get one (no one would call me an "early adopter" but I'm no luddite either). No doubt, I'd have an easier time driving to new places with a GPS. But I feel like I'd lose something, too, and not just the more durable route knowledge that Ishikawa investigates. There's more than easy navigation to be gained from looking around you, studying what's passing by as you drive, and even from the occasional wrong turn.

Not just where, but why?

I'm five posts into this blog, and I haven't yet explained myself.

In my family, I'm known as the one who gets lost. My dad, who used to sell steel all over the world, would wander around Karachi, Dacca, and Mumbai the day he arrived and take shortcuts back to his hotel. My brother, separated from the rest of us in a mall at age two, found his way back to our car and sat on the hood to await his frantic family. My mom and sister have no such navigational boasts that I know of, but neither do they get lost the way I get lost (habitually, spectacularly). I won't waste time cataloguing the scenes of my woeful wayfinding but they range from the Mojave Desert to the stacks of my college library. And don't get me started on driving in Boston.

Here's the weirdest part. Despite all the wrong turns and misadventures, I suspect I might actually have a superb sense of direction that I haven't properly tapped. So, I'm on a mission to find out. Along the way, I'll dig into the mysteries of this curious cognitive skill--what it is, where it comes from, and why we feel its absence in our bones.

Free to be you and me

Speaking of Thomas Wolbers (see previous post). He's a co-author (with Mary Hegarty ) of an article in the current issue of Trends in Cognitive Sciences that lays out a model for investigating why some of us are hardly ever lost while others of us, ahem, have the sense of direction of a loaf of bread. The paper, "What determines our navigational abilities" uses existing literature on human navigation experiments to develop this three part model: Here, we consider three interdependent domains that have been related to navigational abilities: cognitive and perceptual factors, neural information processing and variability in brain microstructure. Loosely translated, that means future investigations of "why" our wayfinding abilities vary so much should focus on the sharpness of our sensory perception, the efficiency of our brain's wiring which collects and integrates all that input, including memory, into a "mental map" and the brain areas activated when those mental maps are used by navigators of varying abilities. 

I don't want to get into any copyright trouble here by posting the whole article, but I think a couple of the boxes are well worth the risk, because As Wolbers and Hegarty note, the individual differences model they propose focuses on internal, neuro-cognitive differences, rather than the nature-nurture questions that might underly them. But the boxes bring up some of these issues:

Sex differences

There have now been several demonstrations of a human male advantage in virtual maze tasks and in spatial learning from navigational experience [11,14,19,53,54], somewhat paralleling sex differences in animal species [55]. 


Although sex differences are sometimes more pronounced when tested in simulated environments [14,54], they occur with testing in both real and virtual environments [56] and when the analyses control for video game experience that is often greater in males than in females [19]. Superior performance by males is not found in all tasks at the environmental scale. It is typical when people learn spatial layout from direct experience, but not when they learn from maps, and is also more pronounced in measures of survey knowledge than in measures of route knowledge [53,56]. Furthermore, female performance can vary with hormonal fluctuations, such that women can perform as well as males during low-estrogen stages of their cycle [57]. Object location memory often shows an advantage in favor of females, although this can depend on the type of objects, whether self-motion is involved, and the degree of metric precision required [58,59].

Intriguingly, there appear to be qualitative differences in the environmental cues and strategies that women and men use during navigation and orientation. Women typically report navigating on the basis of local landmarks and familiar routes, whereas men report using cardinal directions, environmental geometry and metric distances [60,61], a result which has been supported by neuroimaging findings [62]. 


Although women do not differ from men in dependence on or ability to use landmarks, they depend less on geometry when reorienting to an environment [11] and are relatively more impaired at finding a target based on directional cues (i.e. environmental slope, [60]). Women also require more environmental cues to remain oriented in an environment [10] and have difficulty following navigation directions based on cardinal directions and metric distances [21]. 


Thus, strategy preferences can reflect proficiency differences between the sexes in use of geometric cues, as well as relative cue salience. In terms of causal factors, there is increasing evidence for the influence of sex hormones on navigational performance [25,57,63–65], and several evolutionary theories have been proposed [66]. However, men and women also differ in navigational experience [54,67] and there is some evidence that wayfinding anxiety mediates the differences between the sexes in navigational performance [67].

And this one:

The impact of genetic factors 


The structural and functional integrity of neuronal circuits is jointly determined by environmental and physiological factors, the latter including genetic predispositions. Genetic association studies in animals have demonstrated various genetic influences on hippocampal processes involved in spatial navigation [78]. Specific examples include the brain derived neurotrophic factor (BDNF) that is known for its role in activity-dependent plasticity and hippocampal long-term potentiation. 


Both processes are thought to underlie the formation of new learning and memories, and suppression of BDNF synthesis impairs spatial learning in rodents [79]. Although direct effects of BDNF on human navigational learning remain to be established, BDNF modulation of hippocampal engagement is a key process in the initial acquisition of information about novel indoor and outdoor scenes [80]. In addition, polymorphisms of the BDNF gene have also been associated with hippocampal volume [81], which could contribute to preferences for specific strategies in a navigational task [46].

A second route for genetic predispositions to affect hippocampal processing and hence navigational abilities involves pattern separation. To distinguish between environments or regions within an environment, hippocampal subfields create orthogonal representations [82]. This ability to pattern separate is directly related to neurogenesis in the dentate gyrus, which is in turn controlled by several genes [83]. Given that ablation of pattern separation in mice induces deficits in spatial learning in a radial arm maze [84], it appears probable that individual genetic predispositions that control hippocampal neurogenesis can have direct effects on

navigational abilities via differences in pattern separation. 


Finally, as spatial navigation also involves executive control processes that involve subdivisions of the prefrontal cortex [33,85], genes that regulate prefrontal functioning should have the potential to influence navigational abilities. For example, given the dopaminergic metabolism in the prefrontal cortex, the gene producing catechol-O-methyltransferase (COMT) is thought to have a major impact on functions such as the manipulation of information [86] and the resolution of uncertainty [87], both of which are involved in spatial navigation. Moreover, COMT polymorphisms also affect prefrontal–hippocampal coupling [88], which is crucial for navigational planning [35].

Taken together, although the existing animal findings strongly suggest genetic influences on navigational abilities, a direct demonstration remains to be established in humans. Given the complexity of spatial navigation, genetic variability is likely to affect navigational functions at multiple processing stages.

Wired for Wayfinding

A friend sent me this recent post on msnbc.com's Body Odd  blog. I've only heard of one other search for human wayfinding genes, a genome-wide association study by Thomas Wolbers at the University of Edinburgh (no published results yet from that study, as far as I know), but I'll bet we see many more such studies soon:

Always lost? It may be in your genes

Posted on Wednesday, March 03, 2010 2:58 PM PT

By Kavita Varma-White, contributor

When it comes to navigation skills, some of us are homing pigeons. Others
are mice in a maze.

The sharp navigators are those who can figure out which way they need to
go in an unfamiliar setting to get to their destination. No GPS needed to
find their way around town. No always stopping for directions. Some folks,
meanwhile, are hopelessly disoriented  — the type that gets lost in a paper
bag.

A new study suggests that skillful navigation just may be in your genes.

Say you are in a city — Washington D.C., for example — and you
emerge from a Metro station to walk to a specific destination. For a
minute you feel discombobulated. But, glancing around, you see the
Capitol building, and a layout of surrounding streets helps you pinpoint
your location. What if the landmark and roads didn't help?

Previous scientific research suggests that humans, rats, chicks, chimps
and even fish use geometry to reorient themselves in space . They
mentally visualize the geometry of their surroundings — corners and
walls — to figure out where they are. But the new study indicates that
genes may play a part in that ability.

The new study, conducted by lead author Laura Lakusta, an assistant
professor of psychology at Montclair State University, 
Barbara Landau, the Dick and Lydia Todd Professor of Cognitive
Science at the Johns Hopkins University, and Banchiamlack 
Dessalegn, a postdoctoral fellow at the University of Chicago,
compared the navigation skills of normally developed adults and
children with people who have Williams syndrome.

"We found that people who suffer from the genetic disorder Williams 
syndrome have trouble reorienting themselves, a basic process that
is shared among human children and adults, and a variety of 

non-human species," Lakusta said. "Our finding that individuals with
Williams syndrome show this kind of impairment suggests an
important link between genes and the system that is used for
reorientation."

Williams syndrome, a rare condition which occurs in one in 7,500
people, is caused when a small amount of genetic material is missing
from one human chromosome. Individuals with Williams syndrome
have strong language skills and are extremely social, but they have
trouble with tasks like doing puzzles or copying patterns or navigating
their bodies through the physical world.

In the study, Lakusta and her team challenged individuals with
Williams syndrome to find a hidden toy in a rectangular room. The
room had two long walls and two short walls and was covered in black
felt. The Williams syndrome individuals were shown the toy and where
it was hidden in one corner of a room. They were asked to close their
eyes and were rotated for a few seconds. Then they were asked to find 

the toy.

When looking for the object, the Williams syndrome individuals — who
were both male and female ranging from age 9 to 27, "searched all the
corners randomly," Lakusta said, as if they had never before seen the
overall geometry of the room or the lengths of the walls and their
geometric relation to each other.

When testing a group of college students and a group of 3- and 4-year
olds who did not have Williams syndrome, Lakusta and her team found
a more typical pattern of responding.

"If we hid the toy left of the short wall and right of the long wall, they
could mentally construct an image of the room and find it, even if they
became disoriented. They would tend to search the geometrically
appropriate corner. They could figure out that there are two corners
where the toy could be. This is the geometric pattern of responding,"
Lakusta said.

"The Williams syndrome subjects could not construct a mental map of
the geometry of the environment," she said.

The study was recently published in the online Early Edition of the
Proceedings of the National Academy of Sciences.

While other research studies have suggested a link that certain brain
areas might be responsible for the behavior of reorienting, there has
been no evidence that it might be linked to a specific gene, Lakusta 

said. "Now we know that, in general, genes can be deleted and we could
see this impairment of orientation."

For those who are navigationally-impaired, this kind of research is a small
but important step in understanding why you may have a hard time getting
where you need to be.

Of Mice and Men (and Women)

Big navigation news out of University College London. In last month's Nature, a group of UCL researchers wrote that they'd found evidence of "grid cells" in the human brain. Scientists have known for a while that rodent brains have these "grid cells," whose accumulated firings map a triangular grid as the animal explores an open area.  They are just one of several specialized navigation neurons that have been found in rats, mice, and a few other animals.

But we don't know as much about our own navigational wiring. After all, opportunities to poke around living human brains are rare, although a few years ago, researchers at the University of Pennsylvania found a way. They asked a group of people with epilepsy who already had electrodes in their brains to identify the source of their seizures to play a taxi video game, providing the researchers with a neural play by play. 

In 2003, the Penn researchers found "place cells," neurons that fired only in response to seeing a given place (e.g. a bookstore), and cells that fired only when arriving at that bookstore, and still other cells that fired only when that bookstore was the virtual cabbie's destination. Two years ago, they discovered heading-specific "path cells" whose activity indicated whether the taxis were steering clockwise or counterclockwise around the virtual town square. But the search for "grid cells" by the Penn researchers and other labs had come up empty. Until now.

"Travel Directions" by Joan Siegel

There ought to be a word
for the way you know how to get some place
but don't remember the names of streets
the number of turns and blinking yellow lights
so that if someone asked
you really couldn't say
except you know the road starts out straight
and when it's sunny the branches blink across
the windshield making you want to rub your eyes
then the road turns sharply uphill past a red barn
where a black dog jumps out to race you for a quarter mile
and finally recedes in the mirror like a disappointment
and you remember the road dips downhill
into the shadows of the morning
where you hear Bach's unaccompanied 'cello
and understand what a good fit the 'cello makes
in the hollow of the body
where grief begins and for an indeterminate time
the road winds vaguely past
houses    people    road signs
while time hums in your ear and you remember
the dream you left behind that morning
which had nothing
to do with where
you are going

"Travel Directions" by Joan I. Siegel, from Hyacinth for the Soul. © Deerbrook Editions, 2009.

Two family member independently sent me this poem the other day when Garrison Keillor read it on the February 24, 2010 "Writer's Almanac ." Listen to it here (preceded by birthday announcements, of course). It made me think of the directions to the freeway given to Clark Griswold in "Vacation":

You go half a block down the street...

...and you'll see a Torino
with no wheels on it.

Inside that Torino is my cousin, Jackie.

Tell him that you're my boy,
and that you're lost.
                  
He'll make sure you
get where you're going.
                   
You don't want to know from me.
I'm not from this neighborhood.

I'm from the west side of Chicago,
here on vacation.