Let's Reminisce: The benefits of not remembering
There is a strong market for books that praise our mental habits. Authors have lately offered support for the benefits of everything from swearing to grumpiness. Now Scott Small, the director of the Alzheimer’s Disease Research Center at Columbia University, joins this group with his upbeat views on one of our more profound mental shortcomings: forgetfulness.
In his book entitled “Forgetting,” Dr. Small writes that until fairly recently, he and most other scientists believed that forgetting was simply a technical glitch, a bug in the system. For most of his 35 years as a memory specialist, he viewed retaining information as “always the noble goal” and forgetting as lamentable, to be avoided at all costs.
But recent research in neurobiology, psychology, medicine and computer science tells another story. In a boon to spouses like me, it turns out that mentally misplacing facts and details is not just healthy but psychologically necessary. When we draw a blank or stumble over a forgotten word, we are merely evidencing a “cognitive gift” that helps us humans adapt to the chaos of our lives.
Since he works with Alzheimer’s patients, Dr. Small is keen to make clear that he is not romanticizing a pathology. Rather than “poeticize” memory-related diseases, his book concentrates on what he calls “normal forgetting,” which he says keeps our brains flexible enough to invite new experiences, recover from traumas and help us thrive.
Our lives are informed by our memories. We know how to navigate our days—where to go, how to socialize, when to flee—from our recollections of what happened in the past. Yet even the most ordinary life is filled with variability; no one’s days are exactly the same. Dr. Small argues that we are able to improvise the best way forward because we consistently let go of the details that we don’t need— our “memory toolbox” regularly trims out unnecessary details.
The job of forgetting, which involves saving only valuable memories and otherwise
wiping clean the crowded slate, is so big and important that it helps explain our need for sleep. Why we spend around a third of our lives in an unconscious state and vulnerable to our surroundings has long been one of biology’s great mysteries. The renowned geneticist Francis Crick hypothesized in 1983 that sleep was essential for deleting extraneous information. “We dream,” he said, “in order to forget.”
Scientists only recently confirmed this theory. Given the time-consuming work of forgetting, it makes sense that we are meant to spend so many hours dead to the world. The disorientation we feel when we are sleep-deprived may have less to do with physical fatigue than with our brains being overloaded.
Flexibility and creativity appear to be hallmarks of a brain kept limber through judicious forgetting. Animals that have been manipulated to develop a stronger memory are able to
navigate a maze faster, but they have serious trouble adapting when the maze is even slightly altered. For the animals to learn a new way out of the maze, scientists have to increase their ability to forget.
People with autism lack the ability to practice helpful forgetting, and they have trouble synthesizing and generalizing a range of cues, making it hard for them to see the big picture. They tend to lack the flexibility that comes with the memory pruning and clearing that most of us have.
Dr. Small’s book has convinced me that the kind of judicious forgetting that occurs as we sleep is necessary in order to avoid having a brain as cluttered as a hoarder’s garage workshop.
Jerry Lincecum is a retired Austin College professor who now teaches classes for older adults who want to write their life stories. He welcomes your reminiscences on any subject: firstname.lastname@example.org.