Jun
27
Armchair cartography
Filed Under Technology, Wired, Recent stories | 1 Comment
“Cartographers manufacture power,” the eminent geographer J.B. Harley once wrote. So what happens to that power when cartography goes digital? That’s the question I endeavor to tackle in my latest feature for Wired, “The Whole Earth Catalogued.” It’s just out, in the July issue that features the Transformers movie on the cover (or alternately, if you for some reason elected to have your cover “personalized,” it features my story and you on the cover. It’s just like that booth at Six Flags!) In any case, the story is also online here.
As the online version’s headline implies (or possibly, overstates to the point of self-parody), it’s about how Google Maps and Google Earth are altering the way people relate to geography. Perhaps more interestingly, it’s about how thousands of people have taken the tools made by Google and other companies to become their own mapmakers.
This entry was posted on Wednesday, June 27th, 2007
del.icio.us Digg RedditJun
9
New research on the brain mechanisms for déjà vu
Filed Under Science, Deja vu, New York Times | 1 Comment
In Science this week, MIT neuroscientist Susumu Tonegawa and colleagues describe their recent research illuminating the biological mechanisms behind the sensation of déjà vu. (The journal paper is locked up, but there’s a good Scientific American account of the research.) The authors conclude that a set of neurons located in the hippocampus — specifically in an area called the dentate gyrus — fire to create a blueprint of a particular location. When that neural circuit is triggered incorrectly, set off perhaps by similarity between elements of a new location and one we have been to, we experience the sensation of déjà vu. Tonegawa used a clever mouse model to provide evidence for the hypothesis (from the MIT description):
In experiments with mice genetically engineered to lack a certain gene in the dentate gyrus, Tonegawa and colleagues pinpointed the signaling pathway underlying the recall of specific places.
Different sets of mice were placed in two similar chambers, one of which gave them a mild foot shock. After three days, the mice began to freeze in fear in both chambers, even the one in which they had never been harmed.
Within two weeks, the normal mice learned to associate only one chamber with the foot shocks while recognizing the second as safe. The genetically engineered mice “had a significant but transient deficit in their ability to distinguish similar contexts,” McHugh said.
The theory fits well with the Chris Moulin’s research at the University of Leeds, which I wrote about in the New York Times Magazine last year. The neurons Tonegawa identified in the hippocampus mirror the “recollective experience circuit” that Moulin and his colleagues hypothesized as the source of déjà vécu, a condition of persistent déjà vu:
This entry was posted on Saturday, June 9th, 2007
del.icio.us Digg Reddit