You are here

This week’s column is dedicated to people, of any gender, whose favorite part of the map is where it says “You are here”. It was previously thought that in order for you to recognize you are here, you should have been somewhere before that. Last June 18, the journal Science published two independent articles that it may not be so. Experience may not be the one to make for your sense of space because your sense of space may be there even before you start learning your way around.

In order for you to have a sense of space, you need to know your direction, location and the distance travelled. In your brain, there is a part that is shaped like a sea horse. It also looks like a blue-tooth earphone that you hook on the contours of your ear. It is called the hippocampus and it is responsible for spatial memory and navigation. This is the brain part that has three kinds of cells that seem to specialize in the particular aspects of direction, location and distance.

The two studies were “Space and direction are already represented in specific neurons when rat pups navigate a location for the first time,” by Rosamund F. Langston, James A. Ainge, Jonathan J. Couey, Cathrin B. Canto, Tale L. Bjerknes, Menno P. Witter, Edvard I. Moser, and May-Britt Moser and the other, “Development of the Hippocampal Cognitive Map in Preweanling Rats” by Tom J. Wills, Francesca Cacucci, Neil Burgess, John O’Keefe. They chose rats because they have brains that are anatomically similar to human brains and also because it is neither ethical nor legal to implant sensors inside healthy human brains. The first study used both male and female rats while the second one only used male rats.

In both studies, they found out that the cells involved figuring out direction were already present the minute that the pups were born and the other cells, developed and matured rapidly a few days right after, just soon after the rats were able to open their eyes. They found that the directional cells were the first to mature, followed by the “place” (locational) cells and then by the distance cells. This proves that the wiring to get us from here to there already exists without extensive experience in moving around.

The study however does not prove why some minds are better than others in finding their way or why males are generally perform better at spatial memory and navigation tests. If the two experiments conducted say that nature is generally fair in endowing brains with good foundations for “space” intelligence, then the cultures we grow up in may just be what determine how good or bad we are in terms of our sense of space. And that is what it makes it even more intriguing to me.

The most frustrating answer you could get if you try to ask directions in this country from mostly men standing around on street corners (someone I know calls these men theoretical physicists) is “sa banda riyan” or “kumuwan ka, tapos ganun (with gestures).” There is no definite point in their statements to which you can attach an arrow to guide your feet or steering wheel. This may be why they are all standing around in streetcorners — they themselves do not know where they are going. So what makes for that kind of leaky compass in those heads? I have not come across an answer to that in pure neuroscience yet except to say that when you damage your hippocampus, you will surely feel lost. But on why a generally healthy hippocampus could never find direction, part of the clue may be on language.

 I came across the ideas of Guy Deutscher, a linguist who was interviewed by Robert McCrum in The Observer last June 13, 2010. Deutscher raised a very good point in that some languages are more precise than others in terms of describing “space.” Given that, how do these languages change the brain?  

Deutscher cited the Guugu Yimithirr, aborigines from north Queensland who instead of saying “The child is behind the tree.” would say: “The child is north of the tree.” He also said that these people would say things like “I left the pen on the southern edge of the western table in your northern room in the house.” which, to me is both beautiful and useful because the sentence is as much a map as it is a declaration. These people are raised with such an intense awareness of where they are and where they are going that their language reflects this. Obviously, other languages do not have this kind of precision. This is what makes Deutscher ask how then could these variations in languages affect the wiring in our brains?

I think like in all things, it is never enough to just have the equipment (hippocampus) to find your way. In order to be really good at it, we have to be nurtured in cultures that would require that we find our way around. Somehow, we Filipinos have found our way to survive even with relatively vague terms for directions. So I guess, the bigger question is, how has all the customary response of “sa banda roon” (over there) and “sa banda riyan” (over here) shaped our minds?

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