We all have selective memory
MISCONCEPTIONS ABOUT HOW OUR MEMORIES WORK ARE COMMON — ESPECIALLY WHEN IT COMES TO AGING
Matt Griffin, 54, thinks about his father, Grady Griffin, every day, but can’t remember the date of his death: “... The thing I know that is ever present is my dad is gone, and I miss him.” Experts agree. Memory, no matter what your age, is fallible and malleable.
Mental acuity has been a flashpoint affecting both U.S. presidential candidates, more so following a special counsel report into Joe Biden’s handling of classified documents. The report noted Biden, 81, had trouble recalling the years he served as vice-president and didn’t remember the exact date his son Beau had died. Donald Trump, 77, has struggled with memory lapses, most recently confusing Nikki Haley with Nancy Pelosi.
Several memory experts noted the cognitive abilities of Biden and Trump can’t be evaluated based on anecdotal memory lapses. Memory lapses at any age are surprisingly normal and, for most people, aren’t a signal of mental decline.
“Most of us have memory slips all the time,” said Earl K. Miller, professor of neuroscience at the Massachusetts Institute of Technology. “We can’t remember dates or names ... It’s when people get older that mistakes in memory seem to have more significance. Memory lapse really is normal at every stage of life.”
HOW OUR MEMORIES WORK
Our brain can process and hold vast amounts of information, but it has limits. Facts, dates and events can be stored and recalled for days and weeks — or even across a lifetime. As new memories are created, the brain must prioritize important memories, making it more difficult to recall less important details or events.
Unlike a computer, our memories are not fixed and permanent. Stories we tell about our real memories may shift and change over time, and misremembering is common.
“Memory is never perfect even when it seems perfect,” said Miller. “We remember what we want to remember. That’s true for everyone at every stage of life. If we literally remembered everything, it would be too much for our brains ... We always have selective memory.”
WHY FORGETTING IS NECESSARY
Our memories are centred on our life stories and what has affected us the most.
“We don’t want a memory system that’s going to encode every single trivial detail of our experience and retain that over time,” said Daniel Schacter, psychology professor at Harvard University and author of The Seven Sins of Memory.
“The possible consequences of retaining every detail of every experience might be a very cluttered mind and an inability to sort through relevant and irrelevant experiences,” Schacter said. “... forgetting ... on balance is probably a good thing because we end up, by and large, remembering the most important things.”
According to Sheena Josselyn, a senior scientist at the Hospital for Sick Children in Toronto who studies memory, forgetting allows us to identify important knowledge from our experiences as we age.
HOW MEMORY CHANGES AS WE AGE
“It’s very clear that there are a number of changes that occur with aging and cognition that are just part of getting older,” said Bradford Dickerson, a professor of neurology at Harvard Medical School.
Declines in the ability to think and remember among the elderly are broad and almost universal, he continued.
“The raw power of our memory tends to peak in our early 20s,” said Thomas Wisniewski, a professor of neurology, pathology and psychiatry at NYU’S Langone Health. Mental acuity begins a long, slow slide from then on.
Some of this decline probably is due to structural changes that occur throughout the brain, starting by mid-life, said Jason Shepherd, an associate professor of neurobiology at the University of Utah.
The most obvious impacts of age involve processing speed, Dickerson said. Everything gets slower. The effects can be seen most clearly during speech, he said, an activity that takes place at relatively high speeds and requires considerable mental juggling and swift recall. “But word retrieval becomes more difficult with age, so people stumble while talking,” he said.
Aging also “magnifies any vulnerabilities that already exist,” he said. “If someone had difficulties speaking as a young adult, for instance, then getting older is likely to worsen the problem.”
At the same time, older brains can be especially susceptible to stress, distraction and fatigue, he said, all of which worsen memory recall.
“There’s evidence that older adults can strategically focus memory” on the most important information, Schacter said.
Older brains often become more adept than younger brains at filtering irrelevant information or at making connections between experiences, the researchers agreed, because they’ve had more of them.
“An older brain is a wiser brain. It has experience to draw on,” Miller said.
“The thing I’d most like people to understand is that, yes, there is some normal cognitive decline during aging,” Shepherd said. “But it’s not a disease state. It’s part of life.”
Wisniewski agreed. “We should not be prejudiced about age” and thinking ability, he said. “... many very elderly people remain quite sharp, mentally, and they also have a great depth of wisdom and experience.”
WHY WE OFTEN FORGET DATES AND NAMES
Remembering dates and names can be particularly difficult unless we make a point of rehearsing and strengthening those memories.
Memory for “when an event happened is something that for everyone, regardless of age, is one of the most vulnerable aspects of memory,” Schacter said.
Names are also harder to recall because they “have no inherent meaning,” Schacter said. The inability to retrieve names is a common complaint of aging but not a sign of cognitive issues, he said.
“Pretty bad for the special council to criticize Biden for not recalling the details of his son’s death,” Michael Lawson, 36, an architect wrote on Threads. “My mom died more than 10 years ago, and the day of her death is very memorable but not one I actively maintain in my memory library ... The fuzzy memories, the way I’m not totally clear on exactly what she said, here and there, is fine with me.”
Most of us have memory slips all the time ... It’s when people get older that mistakes in memory seem to have more significance.
— Earl K. Miller, professor of neuroscience