Are you middle-aged or older and having problems remembering details, like where you left the keys or parked your car? Cheer up, it may simply be result of a change in what information your brain focuses on during memory formation and retrieval, rather than a decline in brain function, according to a study by McGill University researchers. In the study, published in the journal, NeuroImage, 112 healthy adults ranging in age from 19 to 76…