Thursday, November 25, 2010
Becoming a GPS zombie - eroding your brain.
Almost every day I get an "I just came across your blog, and thought you might be interested in....." which is basically a request that I link to the site to increase their web traffic. I've started to reflexively delete such emails, but paused with one from the health editor of msnbc.com, Melissa Dahl, pointing me to their piece on recent work done at McGill University, noting comments from one of the collaborators, Veroica Bohbot (who is a co-authors of no less than 14 papers presented at the recent annual meeting of the Society for Neuroscience, which I used to loyally attend.) All deal with the two major options we use to navigate our world: a spatial strategy depending on our hippocampus which builds cognitive maps landmarks as visual cues, and a stimulus-response strategy depending on the caudate nucleus in which we follow 'turn left', 'turn right' instructions of the sort given by a GPS device. During aging we shift increasingly from the spatial to the response strategy as our hippocampus function declines. The McGill workers found a greater volume of grey matter in the hippocampus of older adults who used spatial strategies. And these adults scored higher on a standardized cognition test used to help diagnose mild cognitive impairment, which is often a precursor to Alzheimer's disease. These findings suggest that using spatial memory may increase the function of the hippocampus and increase our quality of life as we age.. Another example of "Use it or lose it." Using a GPS device is sparing us the work of exercising our hippocampal spatial navigation circuits, and thus could easily enhance their decay.