Folks tend to worry about memory loss. Our worry escalates when we do such things as lose keys, forget names when making introductions, or remember the principal item that sparked the shopping trip just as we arrive home.
We’re mostly focused on the future, but memory connects us to our past. It provided the information that got us to where we are now, and thus also to where we’re going—so memory loss isn’t something trivial. And yet, occasionally forgetting things doesn’t necessarily signal mental decline.
I’ll shortly roll out the garbage can and recycling box for the morning pickup. I’m getting rid of the remains of some of this past week’s pleasures. What’s left as garbage no longer interests me. At age 74, I think of much of the memory loss I experience in such terms—as information I once enjoyed but no longer need. Today’s newspaper adequately replaces those I placed in the recycling box.
Memory is a complex ill-understood phenomenon. We can think of it as being composed of (1) the robust general knowledge of our world that we acquire through life and continue to use successfully without much decline, and (2) the more vulnerable specific acquired knowledge of things that we’ll use for a short time or only in very specific situations.
We can also think of memory as being composed of (1) skills, such as knowing how to ride a bicycle, and (2) facts, such as knowing the name of the bicycle and how much it cost. Skills are difficult to master and forget. Facts are relatively easy to master and forget.
Personal memories of important experiences tend to be robust and adaptable. Still, we often edit our childhood experiences when we recall and relate them as adults. That’s OK, because the general feeling of the event is typically more important than the absolute accuracy of the story. Conversely, cultural memories (such as of telephone numbers and state capitols) typically require precise recall, and our feelings about the facts are often unimportant.
Memory formation requires the information to be novel and emotionally intense (What’s to learn if we already know it—and why learn it if it’s not emotionally important?). As we age, the cumulative experiences of life tend to reduce the amount of novelty we confront, and we tend to structure our life to reduce emotionally intense experiences, because emotion uses a lot of energy. So it’s not that we can’t learn new things; it’s more that we often prefer not to expend the effort.
On a personal note, I may now forget mundane things and names (proper nouns being an especially vulnerable element of memory), but I have no trouble learning and discussing complex new developments in the cognitive neurosciences. Why? They’re novel, they fascinate me—and vocabulary develops easily throughout life if the concepts are novel and interesting.
The biology of memory loss as we age seems to result more from neuronal problems in our brain’s lower subcortical areas (that synthesize many of our brain’s regulatory neurotransmitters) than in the upper cortical areas (where many factual memory networks appear to be located). For example, Parkinson’s Disease results from neuronal loss in the subcortical substantia nigra, which synthesizes dopamine. Alzheimer’s Disease results from neuronal degeneracy in the subcortical hippocampus, which plays an important role in long-term memory formation. Attention is obviously essential to learning, and the (principally subcortical) systems that process attention decline with age.
Although degenerative pathologies can develop in anyone, it’s important for older folks to do what they can to enhance the health of their brain and body—to remain cognitively curious and active, and to maintain their body systems through proper diet and exercise. Richard Restak’s Older and Wiser is an excellent source of specific suggestions.
As we age, we come to realize that our get-up-and-go has got-up-and-went—so we adapt. We seem to do as well as younger people on factual memory tests if we’re not required to respond quickly (and what’s the rush?). We collaboratively remember things—spouses and friends gradually work out a remembrance by jointly assembling the bits and pieces of data that finally lead to recall. We simplify our life through such strategies as identifying a single place for keys, maintaining a written schedule of commitments, and following standard rituals for medication. We tend live more in the present, and so discover its many charms that had passed us by in our earlier more frantic life.
When I’m doing a presentation, I occasionally can’t think of a word that I need to use. Years ago, I was very embarrassed whenever this happened. Now I just stop and explain the concept as best I can, and ask if someone can provide the word that I can’t recall. Someone always does, and I continue on, unabashed. How nice to reach that stage in life.