The overworked, overcrowded middle-aged mind can be forgiven a few memory lapses.
Is it possible, from a scientific point of view, that NSW former premier Barry O'Farrell had a "senior's moment" when he forgot about the $3000 bottle of wine he received as a gift? Kind of.
At 54, O'Farrell is deep into middle age, according to a 2012 study published in the British Medical Journal that found cognitive decline begins at about 45, not at 60 as it was once thought. Already O'Farrell is experiencing some level of age-related memory loss and a slowing of his reasoning processes.
Further, memory loss is exacerbated by stress. As Harvard Medical School's neuroscience newsletter, On The Brain, noted last year in an article on the middle-aged brain, the hormone cortisol – released during the "fight-or-flight" response to stress – can prevent the brain from laying down new memories or from accessing existing ones. Worse, it can damage the hippocampus, the part of the brain most associated with memory storage.
"Excess cortisol can make it difficult to respond to stimuli or retrieve the stored memories needed to guide us in certain situations, a condition that may account for our being bewildered when stressful situations arise," the newsletter reads.
Well, who wouldn't want to flee the spotlight of a corruption inquiry? So let's leave O'Farrell with that comforting thought and shine a light on all middle-aged folk, the multiple fronts where their lives have become a form of combat, including the nagging worry that they are losing their minds.
Who doesn't want to flee reality when your teens are carrying on like emperors, your ageing parents are on the phone again with a fresh crisis, your divorce is in train, your job may not survive the next round of redundancies, your doctor is rabbiting on about diabetes, your prostate, your lower bowel, your weight, your eyes are demanding glasses, and . . . well, where are the bloody car keys so I can get the hell out?
The overworked, overcrowded middle-aged mind can be forgiven a few memory lapses. So take a breath and tell yourself: "Damned cortisol, that's all it it is." Except it's not.
While it can be galling to realise you can't run or lift heavy objects with the ease you knew as a 20-year-old, it's frightening when you walk from one room to another, full of purpose, only to find yourself standing without a clue as to what task you were in the middle of. Especially if only the other day you left your keys in the front door. And so on.
There was a time you'd laugh it off. Now, in your 40s and 50s, there's a worry that these lapses are the first signs of dementia, that you're one day too soon going to look in the mirror and wonder who that is.
Dementia – and, of course, the dark lord of dementia, Alzheimer's – reached epidemic proportions in Australia five years ago, according to an Access Economics study, commissioned by Alzheimer's Australia.
Last year, the Facing the Health of Australians survey of 5000 people aged 32-55, commissioned by the Australian Medicines Industry, found dementia was second only to cancer as our greatest health concern, more feared than diabetes, obesity or depression. An estimated 280,000 people have dementia in Australia. That number is expected to double by 2030 and reach almost one million by 2050.
In other words, for ageing baby boomers and gen Xers, the epidemic riddling their parents' generation today looms as their own plague of tomorrow. And maybe, recalling when you forgot why you came into a room, it's happening now.
Professor Peter Schofield, executive director of Neuroscience Research Australia, (NeuRA), says the fear that middle-aged people harbour about dementia isn't unreasonable. "It's true that age is the biggest single contributor," but the fear is overblown, he says.
"Yes, as we age our brains shrink. Yes, they slow down a bit. We begin to lose neurons and they aren't replaced at the rate they once were. And so in some measure we are not as sharp or quick as we once were. But in the vast majority of people in their 40s, 50s and 60s, that lack of sharpness is more a function of the complexity of what their brains are dealing with . . . it's more a matter of selective attention than a measure of clinical pathology."
But because dementia is a high-profile issue, "many people are much more anxious about it. Every time they can't find their keys is an impending sign of dementia. Losing your keys is an anxiety issue, not a cognitive one."
Schofield says people "attribute too much to middle age" as a time of mental decline. "It's when you're 70 and 80 years old having a senior moment that you're more likely experiencing mild cognitive impairment. Even then, generally, it's not enough to be lifestyle-disabling."
Kristyn Bates, research assistant professor in experimental and regenerative neuroscience at the University of Western Australia, says the prevalence of middle-aged and older people scaring themselves into wrongly thinking they're losing their minds is so high it has led to the creation of a new area of research – "subjective memory complaint".
"There is nothing wrong with their memory that we can measure. They perform normally. Because it's poorly defined, the prevalence of subjective memory complaint is between 20 to 50 per cent of the elderly population," says Bates.
The key issue here is that the healthily ageing brain doesn't lose memories, they just take longer to retrieve. As Marshall Dalton, a former research assistant at NeuRA, notes in a blog written in part as a response to frequently asked questions, "age-related memory problems are the result of reduced efficiency in communication between brain cells, whereas memory problems in dementia are the result of cell death".
In many instances when our brain seems to be malfunctioning, it's actually taking charge. In that moment when you walk into a room and forget what brought you there, Schofield advises: "Perhaps the task was displaced by a more interesting thought or event. When you forget what you were doing, it's possibly because it wasn't so compelling. Most of us don't have hugely long attention spans."
One of Schofield's's research interests is the genetics of brain function. One of those functions is the ordering of information, and giving priority to certain thoughts and events over others. This includes everything that we consciously see that's going on in the world – our eyes being a physical extension of the brain. The brain takes it all in, both focusing and editing what's happening in front of us.
This leads us to the unnerving issue of false memories – some researchers argue that every long-term memory we have is in some way false. This is because memory is a reconstruction, not a video recollection. When a new memory is acquired it goes through several different processes, firstly at the synaptic level (the junction where information is passed from one nerve cell to another), which takes hours; and then in the hippocampus, the part of the brain where new memories are laid down.
Each time we drag up a memory, it's been altered in some small way because of the circumstances we're in at the time, because of the motivation for recalling it or because new information has somehow mixed in with the original event. Why? It's thought largely to be a function of adaptation, and the brain being efficient.
The net effect is that memories, unless they have been planted by suggestion, are true enough.
Schofield says it could be that memories are moved from one part of the brain to another, like a filing system being shuffled. "The things you think about more are replayed more often. But there's a huge subjective element . . . in often replaying the memory, you form false recollections."
Last year, researchers from the Massachusetts Institute of Technology successfully planted false memories in mice. This was hailed as having great potential for treating sufferers of post-traumatic stress disorder, where bad memories could be edited into happier ones.
There are studies that show older adults are sometimes more likely than younger adults to remember events that never happened, but this may be a self-protective mechanism. A University of Virginia study from 2005, "With Sadness Comes Accuracy; With Happiness, False Memory", found happiness tends to generate false memories, while unhappiness dredges misery.
This isn't to say false memories generate the greater happiness and contentment that people 50 and over are routinely said to experience, but they may be both an expression and reinforcement of that happiness.
The On The Brain newsletter reported a study that found the middle-aged brain screens out negative emotions when confronted with negative images and is otherwise wired to accentuate the positive. It also noted that the brain in middle age may be more resilient that at any other time in life.
In fact, there is growing evidence that the middle-aged brain is more of a good-news story than a sad one.
Bates, of the University of Western Australia, says when she was an honours student in 2000, it was still thought the brain stopped producing neurons past childhood. "We now know that isn't true. Evidence came out last year that the hippocampi [we have a hippocampus in each hemisphere] each makes 700 new neurons every day."
She says that while middle-aged brains begin to lose synapses and there is an associated slowing of some functions, it's now understood that "in middle age people use their brain differently. Both sides of the brain are used to process information, rather than just the one side".
It's not yet understood if this is a natural offset to lost function, but the net result is better communication between both halves, and a greater ability to better judge situations and evaluate information. "What we're seeing is the biological basis for wisdom that comes with ageing."
The best news is that the decline of the brain can be slowed – even repaired – by doing the same things that keep our hearts healthy – exercise, good diet, manage stress. The best exercise seems to be education.
Says Bates: "There's a dogma in neuroscience – the cells that fire together, wire together."
In layman-speak? Use it or lose it.