Human beings, heavily dependent on the ability to clearly and efficiently communicate thoughts, fears, and desires to others around them, have no greater tool than the metaphor. When we sing our children a lullaby, we tell them that they are our sunshine. From our bosses we hear that time is money. When our lovers depart, we complain that they had broken our hearts. What metaphor, then, might we use to describe our brain?
It's far from a trivial question. To truly comprehend something, we must be able first to simply describe it. And what could be more pressing for us to understand than the operating system that governs our bodies?
An operating system, of course, is a very faulty metaphor. The brain isn't a piece of software. Nor is it, metaphorically speaking, a muscle, as some purveyors of educational games that promise to make us more mentally agile declare. Our brain isn't just some layered fatty tissue; it's an intensely complex organ with upwards of 100 trillion synapses, all of which fire repeatedly and drive us to do anything from solving a puzzle to composing a concerto. How, then, might we capture such complexity?
I have a simple suggestion, one that I think may resonate: our brain is like a smartphone.
"Like human brains, smartphones have a maximum capacity that can not be surpassed, and, also like human brains, these capacities vary from unit to unit, with no two being quite alike."
Take a moment to pull that slick little gizmo from your pocket or your purse. Like human brains, smartphones have a maximum capacity that can not be surpassed, and, also like human brains, these capacities vary from unit to unit, with no two being quite alike. Some are built to store massive quantities of information, while others barely have room for a few simple applications. The geniuses at Apple talk of gigabytes; neuroscientists would speak of cognitive capacity or "neurocapacity".
It's a fancy term incorporating a host of things we're all familiar with, such as the way your mental resources are depleted by stress or lack of sleep or other taxing circumstances, the way your brain ages, and the nature of your cognitive reserve, or just how well your mind can resist the deterioration of brain disease. To see this idea in action, consider a groundbreaking 2013 study about the effects of poverty on cognitive function. Interviewing two groups--shoppers in New Jersey and farmers in India--the researchers directed the conversation by asking their subjects to think of a large pending financial expenditure, and then asked them to perform simple spatial and reasoning tasks. The poor did poorly. The reason, the researchers concluded, had nothing to do with stress, or with effort, or with time spent on each task, or with nutrition; it had to do with the fact that the poor had already depleted some of their neurocapacity when thinking about a pending expenditure, leaving less capability for other tasks.
Which, I think, makes the smartphone metaphor sound more apt than it might've otherwise: if your capacity isn't well-managed or isn't large enough, the machine will perform in an unsatisfactory fashion.
Luckily, there's a lot we can do to maximize it and recharge it, from designing ways to effectively measure neurocapacity to measuring the impact of variants like sleep and light to increasing neurocapacity by means of non-invasive electrical stimulation. All these are already happening in labs across the country, but they're hardly enough: to truly regain, retain, or increase optimal brain performance, we must make brain health a priority.
What do I mean by that? Walk over to your kitchen cupboard and look at the cereal box or the other snacks you may keep there. Chances are, some of them are emblazoned with some cheerful stamp that pronounces them "heart healthy." Ask your neighbor or the person behind you in line at the grocery store what does heart healthy behavior entail, and he or she is likely to know precisely which foods are good and bad for the heart, which exercises are recommended, what lifestyle choices are celebrated. But ask the same person how might one go about and keep a healthy brain and you're likely to get a blank stare or, worse, some bit of misinformation.
"Which, I think, makes the smartphone metaphor sound more apt than it might've otherwise: if your capacity isn't well-managed or isn't large enough, the machine will perform in an unsatisfactory fashion."
Let us not wait, then, until our brains are sick to treat them. Let's devote the next few years to educating both public health professionals and the public at large on evidence-based practices that keep our brains healthy, separating those that truly have an impact from those designed by marketers out to make a quick buck. And let's unite our efforts to study distinct fields, from memory to brain performance to mental health, and engage with more rigorous research into the precise nature and scope of neurocapacity. With a population that's rapidly aging--by 2050, more than 89 million Americans will be 65 or older--there can be no more urgent priority. And there's no better time to start than right now. A collective effort on brain health, if I may use an apt metaphor, is the key to our future.