So, I don’t really see the big deal of Parisians making cognitive maps of Paris. First of all, the city was planned by Haussman to be a city of monuments, with the intent of an inescapable visual connection between the avenues and the many beautiful monuments of Paris. Haussman even had buildings constructed at intersections and domes built off-center for the sole purpose of a continuation of his vision. It is no wonder that monuments played such a large part in how the Parisians orient themselves.
Secondly, because they take the subway, Parisians look at maps every single day. Obviously, they are not car-reliant, and thus they go to new and different places all of the time using the subway (as opposed to just commuting to work). I’ve never met a Parisian that didn’t carry a map of the city and metro with them all of the time. (Most use something like a Plan de Paris, which is leather-bound and conveniently small.) Also, I know the city rather well from being there for only 9-months, and even I could remember where the majority of those buildings were.
Perhaps the study could have delved more into the unconscious and everyday of a Parisian. For example, if people within a certain neighborhood were asked to draw the path that they take to the market, what was shown in common between the maps would have been much more significant. I’m sure that one could have learned a lot more about the unconscious of the collective people.