Book review: The surprising advantages of the middle-aged brain

A brain scientist reveals we actually get smarter as we get older (in some ways).

Several times a week, I stand in my kitchen, or among the cubicles in my workplace, and wonder why I’m there. I know something brought me out of my seat, something I wanted to get or needed to do, but I’ll stand there, puzzled and embarrassed, my mind blank. Though I’ve always been scatterbrained, it’s gotten worse over the years. It’s harder to return to a book after leaving it for a day or two and pick up where I left off. And when I think back to how easy it was in school to learn names, dates, facts and formulas, there seems no doubt that I’ve lost a few miles per hour off of my mental fastball. I am 30 years old.

Any reader with a birth certificate of greater vintage is likely snorting right now. “Just wait till you get to be my age, Sonny Jim. You don’t know the half of it yet.” And I probably don’t. But while the decline of our mental faculties as we get older is widely accepted as fact and inevitability, what actually happens to the brain as we age through our middle years is much more complicated than simple deterioration. If we lose our sharpness in some areas, we gain surprising capacity in others; and researchers are now exploring what we can do to ward off the decline of our minds.

The Secret Life of the Grown-Up Brain: The Surprising Talents of the Middle-Aged Mind (Viking) is a roundup of the most recent science on how the human brain ages, as well as a guide to “toning up your brain circuits” to better weather the onset of age – which is itself a relatively new problem for humankind, writes author Barbara Strauch, The New York Times‘s deputy science and health and medical science editor, whose earlier book, The Primal Teen, considered the teenage brain. Just a century ago, the average lifespan in the developed world was about 47 years, and has since risen to about 78. “The serious study of aging is only a few decades old,” Strauch writes. But while she collects plenty of anecdotal evidence about lost keys and struggles to remember people’s names, she also observes that a great many of the middle-aged, “despite not remembering the name of the restaurant they just ate in … are also structuring complex deals between oil companies on different continents and coming home to cook Coquilles St. Jacques.”

The picture that’s emerging through study of the middle-aged brain is of an organ better able to manage emotion and intricacy. Studies observe changes in the reactions of our amygdalae, for example, tiny parts of our brains that play a key role in emotional learning, social cognition, and in generating our fear response. As we age, they become less and less responsive to negative stimuli, and “in some automatic, preconscious way,” begin to accentuate the positive at the expense of the negative.

Meanwhile, our struggles with names and dates is lately thought to be more a problem of retrieval, not storage. They’re there, in our heads; but an aged hippocampus, the part of the brain chiefly responsible for the processing of memories, struggles with random requests for names and facts that lack associative properties. “It’s like trying to find the right book in a well-stocked library,” Strauch writes.

Our aging brains similarly show wear in the realm of episodic memory, the part of brain function that handles recollections of recent events, like the last few chapters of the book you put down yesterday, or what you had for breakfast. University of Toronto brain scientist Cheryl Grady has led the way in studying the performance of the dorolateral prefrontal cortex, key to our ability to concentrate. As we age, that part of our frontal lobe fires less surely, impeded by another part of the brain responsible for what scientists call the ‘default mode,’ which we use to daydream. Our ability to tune out the irrelevant is reduced, and thus do we become more easily distracted as the years pass by.

The trade-off, though, is a brain that’s better networked as it ages. One biological distinction between humans and other animals is a surfeit of the white matter inside our skulls called myelin. A fatty outer coating for our trillions of nerve fibres, myelin is thought by some to be the key to our ability to develop complex skills like language. It helps signals move faster around the neural network, and in two important areas of the brain, the frontal and temporal lobes, myelin levels increase with age, peaking on average around age 50 and in some people continuing to rise into their 60s. Simply put, it gives the brain what one neuroscientist calls “greater bandwidth,” boosting the processing capacity of the affected brain cells by 3,000%. What’s more, while its levels are partly predetermined by genetics, they can thicken and become more efficient with deliberate use. It’s the science behind practice making perfect.

The concept of wisdom is accounted for, too, with areas of the brain that process socio-emotional information less subject to erosion. All in all, scientists identify a “sweet spot” occurring in most of us in our 50s, when our basic cognition is still sharp, and we’ve also accrued enough experience that a complex and nuanced response to the challenges around us is second nature.

Of course, all of this is to some degree variable. Some brains erode more slowly than others, and some remarkable specimens, called “escapees,” show barely any loss of function. How to stave off that loss of function is Strauch’s subject for the latter few chapters, and here the science is least clear.

Education seems to have an impact, and diet may as well, whether skewed toward antioxidants and anti-inflammatories, or toward the drastically lower caloric intake with which one scientist is experimenting. At U of T and elsewhere, labs are running brain-fitness training experiments, hoping to teach focus and the use of more of the brain. Everyone has a pet theory, from meditation to Sudoku.

But the strongest scientific evidence yet gathered points to one simple key factor: exercise. The dentate gyrus, a part of the hippocampus thought to play a role in the creation of memories, wears with age, but it responds to aerobic exercise, stimulating the creation of new neurons. Alone, it’s not a cure for the aging brain – we’re still some way off from that – but at this point, all indications are that it’s the surest means of prolonging the mental sweet spot we enjoy in middle age.

Executive summaries

Why Manners Matter : What Confucius, Jefferson, and Jackie O Knew and You Should Too (Plume)
Lucinda Holdforth

Confirming its quickly growing cult status is the release of yet another edition of this 2007 essay by Holdforth, an Australian author, speech writer, and self-appointed defender of society’s better aspects. From Pericles through Edmund Burke, Borat and New York City mayor Michael Bloomberg, Holdforth offers a history of the idea of manners: why they exist, how they developed, and why they matter today. While some people dismiss formal manners and civility as just a veneer, she views them in a more optimistic light: ‘the artifice as embellishment rather than disguise. A way to enhance and illuminate the inner self, not to hide it.’ And while in some of her grander claims for manners she (proudly) comes off a snob, Holdforth rejects the idea that we should all be enslaved to complicated etiquette guides, instead offering a short set of eight guidelines distilled from the most important principles governing manners, and from common sense. Among them: ‘keep your word, especially about time,’ she suggests; always be aware of whatever it is you’re doing, because ‘multitasking is the enemy of manners;’ and finally, ‘Most of the time, shut up.’

Ship of Fools : How Stupidity and Corruption Sank the Celtic Tiger (PublicAffairs)
Fintan O’Toole

On Sept. 11, 2008, the Asgard II, Ireland’s national yacht and a proud symbol of the country’s past and present, sank to the bottom of the Bay of Biscay. As though in solidarity, the Irish banking system collapsed two weeks later. For almost 20 years, one of the poorest nations in Europe had lived an economic fairy tale, becoming the ‘Celtic Tiger’ after which so many other envious nations hoped to model themselves. But as the global fi nancial crisis spread, Ireland became one of its worst victims, with the IMF predicting its GDP would shrink by 13.5% by 2010, the worst result for any advanced country, and among the worst peacetime economic contractions ever seen. The assistant editor of The Irish Times, O’Toole off ers a set of nine spitting-mad polemics exploring the different aspects of the Celtic Tiger’s regression into ‘bedraggled alley cat,’ from a primitive land hunger that created a ‘new feudalism’ through a corrupt political and anarchic business culture. If Ireland skipped a step in its development, leaping from barely developed to hyper-globalized in a heartbeat, it now ‘has to undertake some quite oldfashioned exercises in nation building,’ he argues, founding a Second Republic from the ruins of the first.

Bennett: The Rebel Who Challenged and Changed A Nation (Key Porter)
John Boyko

Mark Twain (or a latter day imitator) said, ‘History doesn’t repeat itself, but it rhymes,’ and if you give that claim any credence, the first major biography of our 11th prime minister arrives in timely fashion. R. B. Bennett knocked William Lyon Mackenzie King out of office in 1930, assuming office as the Great Depression took hold of the country. Popular history doesn’t remember him kindly — his name’s still synonymous with the Depression’s despised relief camps, and King recaptured government at the first opportunity — but Boyko’s reading of his rule is more nuanced. He suggests that Bennett, despite a reputation as a laissez-faire ideologue, became something of a New Deal-style leader over his fi ve years in power, passing minimum wage and unemployment insurance legislation, and creating the Wheat Board, the Bank of Canada, a single governmentbacked paper currency, and the precursor to the CBC — all consistent with his core philosophies, not just a series of concessions to exigent world events. Prime Minister Harper should be among those curious readers of this reevaluation of a Conservative in activist times.