Is there any truism about cognitive capacity that is more familiar than “use it or lose it?” Of all the things we could talk about in applications of neuroscience, this is one that shows up surprisingly often, even in the conversations I have with faculty and other people who work in higher education. You might assume that we are mostly concerned with developing brainpower in teenage and twentysomething college students, but more and more, higher education is being linked to well-being all across the lifespan. This includes the picture of successful aging that we get when we think of a highly engaged, cognitively active lifelong learner, one who – according to the claim – will stay sharp longer.
And in fact, our learners are coming from a broader swath of the human lifespan, more so than ever before. As is frequently pointed out these days, “traditional” college students – 18-to 22-year olds who go to school full time – are anything but, and students in the non-traditional mold, including those in middle age or beyond, now make up the majority of people participating in higher education.
The use it or lose it concept also ties into big-picture conversations we academics have about the value of learning, and indeed, the physical changes to the brain that take place when we learn something new. If, on top of all the other benefits of higher learning, we educators were able to deliver something that protects you from the supposed ravages of old age? That would be exciting news indeed.
Use it or lose it is an idea that seems to intrigue almost everybody, but I’m drawn to the idea for other reasons that trace back to my scholarly life before I got into the kinds of applied work that I do now. When I was a Ph.D student, and during the early part of my life as a professor, most of my research efforts went toward studying cognitive aging. I did my dissertation on age differences in working memory as they play out in language processing and over the years published several other articles on phenomena relating to aging and memory (examples include aging and short term memory, aging and a phenomenon in rapid reading called repetition blindness, and a similar effect in hearing called repetition deafness).
For all these reasons, I’ve followed the use it or lose it idea for a long time now, examining the evidence, considering different theories, even teaching about it in classes. And from that, I think that use it or lose it may be yet another brain claim that’s appealing, but wrong.
How could such an intuitive, seemingly well supported claim be just that – wrong? The central problem is one researchers wrestle with all the time, establishing clear lines of causality. Yes, people who are successfully aging, or even experiencing lower rates of age-related brain diseases, may report higher levels of cognitive engagement, participating in more activities and more challenging types of activities, compared to their less-healthy counterparts. But alternatively, it may be that the healthier people are better able and more inclined to pursue such challenging activities, so that the lines of cause and effect run in the opposite direction than we assume. Without randomly assigning different individuals to different activity levels, conducting pre- and post-tests and other controlled experimental methodologies, it’s impossible to tell one from the other.
The myriad challenges associated with figuring out the real causes are summarized beautifully in this article by research heavy hitter Timothy Salthouse, who has made massive contributions to contemporary theories of mental aging. On balance, Salthouse concludes, the evidence that “using it” prevents age-related decline is surprisingly weak. And even if there is some value, it may not be the kind of equal-opportunity preventive that we imagine. Rather, it may be that individuals with a long history of cognitive engagement build up more reserves that mask age- or disease-related declines for longer. The real possibility that engagement compensates for, but does not prevent, loss of capacity is also part of this classic article showing that some (but notably not all) memory functions are significantly better in older college professors compared to peers in less cognitively demanding fields.
So, there is that fairly straightforward problem with the research: correlation does not imply causation, and association does not mean prevention. Furthermore, mental training exercises of various kinds usually don’t work (nope, not even crossword puzzles), or when they do work, the training effects tend to apply only to the narrow range of specific activities people practiced on, falling apart when transferred to other sorts of skills. Brain training programs may feel challenging, and we may get better at doing them, but at worst they are like some kind of surreal weight training program that only lets us get stronger at lifting hand weights, not grocery bags or anything else we might try to pick up.
The problems with the logic are glaring. So why don’t we spot them? Wishful thinking is part of it, but it probably also has to do with faulty parallels between mental and physical capacity. The analogy between exercising your muscles and exercising your brain is an irresistible one, and once a powerful analogy like this is in place, it tends to warp your thinking about the problem, so that you make assumptions and draw conclusions that you otherwise wouldn’t. It would be neat if brain power and muscle power worked in the same way, but they don’t, and so we can’t assume that exercising builds power in the same straightforward way in the brain that it does in your muscles.
There’s another parallel that is more reasonable but still problematic, and that is the comparison to neural development in stimulating versus unstimulating environments. I’m thinking here of course of the famous “enriched environment” line of work pioneered by neuroscientist Marian Diamond and carried forth by many others over the course of the last few decades. As we now know, brain plasticity – the physiological capability for change and even growth – does last a lifetime, and it is not that much of a stretch to conclude that if stimulation in early life builds brain tissue, that process continues through the lifespan. But here again, the processes are not identical, and so even without disparaging in any way the enrichment-environment concept, we can’t automatically assume that just any kind of stimulation will have the same effect across different age groups.
And what about major differences that exist even within an age group? Unfortunately, the public discussion tends to conflate the normal ‘healthy’ aging process and disease processes such as what you see in dementia. This always gets my attention, because distinguishing between these two processes was a guiding philosophy of the research group I was a part of back in graduate school. We rejected the assumption that all age-related change is negative, starting fresh with the core belief that aging itself is not a disease and committing to being open to whatever age differences, positive or negative, we might find.
This philosophy helped us make some important theoretical advances. It’s also practical, helping us determine the real impacts of cognitive activity, which might be very different in one kind of aging versus another. The idea that disease prevention might be a different issue than preservation of healthy function is not especially complicated, and yet time and again this line seems to be blurred as we imply – or state outright, as I heard a keynote speaker say once at an education conference – that staying mentally active will keep you from getting dementia.
And this brings up one last, very personal, reason why I think we need to be realistic about use it or lose it. Six years ago, I lost my dad at age 66 to a vicious age-related brain disease. Diagnosed as a form of Lewy body dementia, it destroyed his brain at a breathtaking pace, taking with it not his memory exactly, but rather his ability to stay grounded in reality, perceive his surroundings, and regulate his emotions.
No one understands why some people get a disease like LBD and others don’t, or why it progresses so quickly in some versus others. Regardless, I find it terribly offensive to suggest that if someone like him had only been more mentally active, they would not have gotten sick. At the height of his career, my father was the managing editor of a major newspaper, with a rich personal and professional network and no shortage whatsoever of cognitive stimulation. Granted, his is one case, and a single, possibly anomalous anecdote can’t disprove the existence of a general causal link. Still though, it’s impossible for me to think of use it or lose it as a helpful piece of advice when so much about these diseases is still unknown, and when they are tragically impossible to effectively prevent or treat. It feels to me like blaming the victim.
I wish there were better news I could share about ensuring a healthy brain as we age, something more encouraging than luck and genetics. Fortunately, there are a few reasonably evidence-based things you can do, or not do. Don’t smoke. Maintain a healthy, plant-focused diet (but beware of extravagant claims about foods that supposedly cause or prevent disease). There are also some suggestions that certain common medications, particularly those found in some antihistamines and sleep aids, might increase your risk, so it may make sense to avoid those whenever possible.
And more than anything: Engage in aerobic exercise. This is good for your brain, which is, after all, an organ in your body and one that thrives on a well-functioning cardiovascular system. This is not just can’t hurt/might help advice either; controlled studies such as this one make it clear that increasing aerobic exercise has physiological impacts on the brain, and that these impacts translate into improved cognitive performance. Granted, this is not the exactly the same thing as saying that exercise prevents disease, but it’s one of the stronger links between brain and lifestyle choices, and one that is doable for most people.
As for other positive possibilities to pursue: There may be some value to the cognitive reserve idea, that building up brainpower gives you a bigger buffer against aging and offsets at least some of the early symptoms of dementia. If you are going to pick any cognitive “exercise” for prevention, consider making it a language learning project; there’s some preliminary evidence that this particular way of expanding capacity might have some protective powers.
There’s another often-overlooked, paradoxical, and encouraging fact about cognitive aging. The kinds of declines we document over and over with laboratory tests don’t necessarily translate into reduced performance in the workplace, or functioning in society in general. This fits with my experience running hundreds of study participants, day in and day out, as a graduate student and as a young Ph.D. For all the supposed deficits our older participants had relative to our college-aged ones, guess who never, ever missed their scheduled appointment? Wisdom, the ability to predict and manage our own cognitive processes, planning ability – these can all compensate. Similar phenomena exist in language processing, attention, and other realms of cognition – that older adults function better than you’d predict, due to compensation and strategic shifting of resources to get the job done.
All that said, we still need to keep in mind that we don’t currently have effective anti-aging, anti-dementia cures. But that doesn’t mean we never will. Some optimism is in order, but I think the too-cheery platitudes will get in the way of making the kind of major advances we need. We scientists always say “more research is needed,” and oftentimes that’s just an empty ritual. But in this case, it really is true. More research is needed, and we will need to pay attention to what that research really does and does not say about successful aging, even when our emotions try to lead us astray. And if the public perception is that “use it or lose it” is a settled question, that will actively obstruct us from pushing the research forward.
The psychologist Carl Rogers once said that the facts are always friendly, something that I take to mean that it’s better to investigate and find out the truth about something than it is stick with a comfortable misconception. Scientists take it for granted, but I think we forget that this is challenging, especially when something hits so close to our worst fears for our own lives. Aging is the ultimate fear for many of us, so it’s no surprise that would be so irrational about it. But it’s time for those of us who know better, or who ought to know better, to do a better job communicating the facts, never trading the science for a catchy, authoritative-sounding but wrong piece of advice.