NavList:

Thanks for drawing this book to our attention, Jackson.  I haven't yet read it but it certainly sounds interesting.  

Any possible link between reliance on electronic navigational aids and an increased risk of developing Alzheimer's remains conjectural, but there is at least one neuroscientist (Veronique Bohbot at McGill University) who thinks this a subject worth researching. She has suggested that using spatial memory regularly may improve the function of the hippocampus (decay of which is associated with the onset of Alzheimer's) and that it might help reduce cognitive impairment associated with ageing.

Having discussed this subject with other neuroscientists who work on human memory and navigation I think it's fair to say that hers is still a controversial view, but I note that they didn't dismiss it out of hand.  More research is surely needed.

Best wishes

David