DEAR DOCTOR K: As I get older, I’ve noticed that I have more trouble remembering certain types of information. But other types of memory are as strong as ever. Is this true, or just wishful thinking on my part?

DEAR READER: You’ve made an interesting observation – and an accurate one. As we age, some information does become harder to recall, and new memories may be harder to lay down in the brain. But other memories remain as accessible as ever.

In particular, there is truth in the old saying that “You never forget how to ride a bicycle.” Procedural memory – by which you remember processes and skills such as how to ride a bike, serve a tennis ball or accomplish routine tasks – does not fade with age.

But other kinds of memory are more likely to decline with age. These include:

• Images and details of experiences you have had. For example, which stock you sold last year from your retirement account.

• Factual knowledge, such as remembering the exact year World War I started. (As I wrote this, I realized I wasn’t sure myself which year it was. But, with a little help from Wikipedia, I learned it was 1914.)

• Spatial memory. For example, learning the directions to a new location.

Willpower and effort can overcome some age-related difficulties. We now know that in many instances, if you make the effort to learn something well, you’ll be able to recall it as well as a younger person can.

Mental exercises probably can help, too. This is a controversial area, since some studies have not found a clear benefit from mental exercises, while others have. Why the inconsistent results? There probably are two reasons. The first is that the people who participate in the studies are different. In some studies, the participants have no detectable mental deficits. In other studies, participants have mild cognitive impairment.

The second reason is that there are many different types of mental exercises. Some may work, and others may not. That’s why I’m dubious of absolute statements like “mental exercises work.”