What is cognitive aging and how do we mitigate some of the negative effects?

​In my last blog entry I discussed some of the challenges associated with intervention studies to improve cognition.  However, I didn’t really spend much time defining cognition and cognitive aging.  A very recent publication by the Institute of Medicine/National Academy of Sciences (NAS) provides a book-length treatment of cognitive aging (free to download).

The NAS is a federal entity in the US charged with providing independent, objective advice to the nation on matters related to science and technology.  It has an interesting history going back to the Civil War when President Lincoln formed a group to provide advice related to the war effort.  If I remember an anecdote about that history at a committee meeting over a decade ago, one of the first tasks assigned was to find a way to enable iron-clad ships to navigate when the iron played havoc with magnetic compasses.  Today, much of the work involves commissioning of reports by public and private entities.

I first served on a committee concerned with Health and Safety Needs of Older Workers and have been involved in other task forces as a consultant.  The NAS really does stress the need for objective, independent advice and requires committee members to provide information about any potential conflicts of interest.  I remember being asked to list my investments before being allowed to continue on the committee.  I believe that the NAS had been “burned” once by a committee member who had conflicts that were not identified and might have been seen as influencing recommendations.  Incidentally, for all the work that committee members conduct on behalf of the NAS, they receive thanks, but no payment, although expenses for attending meetings are reimbursed.  A typical assignment might last a year or more before the publication and recommendations are completed.  Independent reviewers also go over the final report before it is published.

I liked their definition of cognition: “Cognition refers to the mental functions involved in attention, thinking, understanding, learning, remembering, solving problems, and making decisions. It is a fundamental aspect of an individual’s ability to engage in activities, accomplish goals, and successfully negotiate the world.”  You may remember in my first blog entry on defining successful longevity that I focused on the important role of goals.  They go on to provide a conceptual definition of cognitive aging: “The committee provides a conceptual definition of cognitive aging as a process of gradual, ongoing, yet highly variable changes in cognitive functions that occur as people get older.”  Their Box S-1 provides a detailed list of features and characteristics.

I think that they waffled a bit about the general direction of changes in that definition, which are mostly negative, else why be concerned and have a committee to detail them and provide recommendations on how to mitigate them?  But, it is worth keeping in mind that the knowledge acquisition process (learning), which goes on across the lifespan, does often result in positive changes in the sum total of knowledge that older adults can call on.  However, that basic learning process becomes less efficient as we age, depending on your skill level in the domain (a topic for another day), and as work my lab has conducted on learning a new word processor has shown, learning rate may be cut in half from the decade of the 20s to the 70s for totally new learning.  Also, as we age we may have increased difficulty accessing such stored knowledge efficiently.  That phenomenon of retrieval difficulty is well described by the “tip of the tongue” phenomena, when we know that we know something, but can’t quite recover it, for instance, the name of someone.  We become less efficient in accessing what we know, though the past history of accessing information and how recently we accessed it play a role in the probability of coming up with it quickly.  Fortunately, today, for those who are technology-savvy, we can turn to our computing devices and search engines to help move that retrieval process along.  I always thought that (ill-fated) Google Glass was going to be particularly helpful to older adults, particularly for face-name recognition which young and old alike complain about.  However, Google decided not to promote automatic face encoding as too intrusive and the project seems to have hit a hiatus.

One good point for the report on cognitive aging is that they came out with 10 recommendations, a number no doubt inspired by the 10 Commandments of biblical times.  I remember our Health and Safety needs committee wrestling with going beyond 10.  The committee has some (relatively) easy to follow recommendations for improving your chances to maintain cognition accessible to the public.  Main advice is to engage in physical activity, reduce cardiovascular risk factors (hypertension, diabetes, smoking), and manage medications properly.  Secondary ones are to be socially and intellectually active (keep on learning), get adequate sleep and be treated for sleep disorders such as sleep apnea, and try to prevent delirium associated with medications and hospitalizations.  They also warn people about the risk of falling prey to financial fraud.  ISL is working with Merrill Lynch on the latter issue, with Tom Blomberg, George Pesta, and myself starting a research project in The Villages.  ISL members such as Walter Boot and myself, through research with the CREATE project are also investigating cognitive interventions such as digital gaming as a way to improve cognition.  At this point in time, though, the best advice is to get up off the couch and do aerobic exercise such as brisk walking at least 3-5 times per week.​