Did I or Didn't I?

All memories are not created equal, at least for the elderly. A study has found that they recall whit they ought to do--say, take their medicine--but often forget whether or not they've done it, possibly over-or under-medicating themselves in the process.

"Prospective memory," or remembering to perform actions in the future, may be difficult at first tot the aged, says psychologist Gilles Einstein, Ph.D., of Furman University in Greenville, South Carolina. Once a task becomes routine, they get it down pat, but may then confuse doing the act with thoughts reminding them to do it.

Einstein asked young and older adults to press a key once during each of 11 computer tasks involving verbal, perceptual and motor skills. Unlike younger subjects, the older folks consistently neglected to press the key early in the experiment, then pressed it too many times towards the end--when they remembered to perform the action, they'd forgotten that they'd already done it, and did it again.

Einstein cites two sources for such errors. First, distinguishing between what you've done and what you imagined you did becomes harder with age. "A task like trying to remember your medication is ripe for contusion," he notes. The elderly also tend to forget exactly when the), performed acts, likely because the brain doesn't fully encode it.

Ironically, a note reminding subjects to press the key only confused them further: "It created more thoughts about the action, which led to more uncertainty," says Einstein. To separate fact from fiction, think carefully about a task as you're performing it. Advises Einstein: "Swirl a pill around your mouth slowly and you'll remember it."

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