Why you’re always forgetting things, according to a memory scientist
“Why drag about this corpse of your memory,” Emerson offered in “Self-Reliance.” It was an invitation to let go of past beliefs and things once said aloud — indeed, former versions of ourselves — for the sake of reinvention.
These days, most of us are instead trying to remember, whether it’s where we left our car keys or reading glasses or who the president of Mexico is. Semantic memory, the ability to recall facts and figures, differs from episodic memory, the ability to travel back to the past in our minds and re-create — however hazily — a scene.
The latter relies on imagination, writes neuroscientist and clinical psychologist Charan Ranganath in his new book, “Why We Remember: Unlocking Memory’s Power to Hold on to What Matters.” Each time we recall past episodes, we reconstruct them anew, “like hitting ‘play’ and ‘record’ at the same time,” he writes. This explains some of the ways memory fails us, whether witnesses erroneously led to think a person in a lineup snatched a purse, or unintentional plagiarism. (Ranganath, who is also a musician, believes it’s plausible that George Harrison truly didn’t realize he ripped off the melody of “He’s So Fine” while writing “My Sweet Lord.”)
“To forget is to be human,” Ranganath asserts. His book largely seeks to reassure the reader, with lucid and rigorous explanations of the relevant neuroscience, that much of our everyday forgetting is just fine. The problems we have with memory — and we have many — arise, instead, from our expectation that it will be accurate and photographic instead of creative and impressionistic. Our minds render the past in surrealist montages, not as cinéma verité; we are more Willem de Kooning than Dorothea Lange.
Evolution made us this way, Ranganath tells us — though he does so without examining what might distinguish the memory-making of humans from that of, say, elephants or crows. Experiences that are the most distinctive, the most emotionally arousing and the most linked to our survival — threats, nourishment, the possibility to reproduce — stay with people more readily. We lose
track of things like our house keys because we use them so routinely that the many instances of key placement interfere with one another, such that yesterday’s instance of an everyday event has little staying power in the mind. Traumatic memories that linger, by contrast, function as warnings to avoid those same dangers in the future — something early humans needed.
Many of the book’s verdicts about how memory manifests are intuitive, if not obvious: A smell or a song can cue up lost episodes from the past, something Proust knew a century ago when he placed the madeleines in Marcel’s tea. When we put down the camera and soak in all the sensory details, we’re more likely to hold an event in our minds than if we see it through the lens. But Ranganath’s book shines when it’s illuminating how this all works in the brain.
His descriptions of complex studies are entertaining and clarifying, and he vividly paints the intellectual history of the science of memory, including how prevailing notions have been unseated over time by experimental research. He’s a generous, humble narrator, telling us about the bets he lost with other scientists whose hypotheses he had dismissed. He describes scientific progress — accurately — not as a product of singular geniuses but as arising “from the collective work of a diverse community.” His self-deprecation adds to his credibility and notably contrasts with the self-aggrandizing tone in many trade books written by scientists.
This is not a book about becoming a memory champion (for that, see “Moonwalking With Einstein,” by Joshua Foer), nor is it a book about avoiding dementia and other memory disorders. But, with a few exceptions — most notably, when he’s discussing the veterans he has counseled who suffer from post-traumatic stress disorder — Ranganath implies that more remembering would be better. But what about the usefulness of forgetting? When should we remember, and when should we try to forget? And do we have a choice?
We know that nostalgia can be a way to linger in the past instead of embracing the realities of the present or the possibilities of the future. Past grievances can keep entire societies from escaping cycles of violence. And on a personal level, don’t we have good reasons to leave behind past notions of self, to constantly reimagine who we are for the sake of living fuller and more creative lives?
When the author Lewis Hyde contemplated such questions through the prism of literature, history and art in his book “A Primer for Forgetting” (2019), he noted that Jorge Luis Borges, who believed that imagination required a blend of memory and oblivion, longed for the liberty to forget himself to be someone new. The composer John Cage used the I Ching’s chance operations to forget known melodies and invent new sequences of notes he hoped people could listen to with more aliveness instead of anticipation. (This also hedged against the risk of even subconscious plagiarism.) Hyde posited that creativity might require forgetting.
Ranganath briefly touches on this when he describes a study showing that people with higher performance on creative thinking tests were more susceptible to being implanted with false memories. But his readers won’t get an understanding of how neuroscience substantiates or challenges the intuitions of Borges and Cage, nor of how memory might hinder or aid their own creativity.
Ranganath does make a brief case that human artists will always outshine AI artists because they draw on varied influences — a notion that becomes more tenuous as AI advances continue to stun. But he leaves aside the question of whether we should be reevaluating the purposes of memory amid technological change. Emerson treated his notebooks as an external memory bank, not knowing that one day people would size up their computers by their working memory. Should we keep ceding more memory tasks to smartphone cameras and artificial intelligence, or do we need to keep training our minds to enhance our semantic and episodic memory?
What’s most compelling about “Why We Remember” is that it offers a scientifically robust rationale to accept with grace that, no matter what happens in this new world, we will not remember everything we want. Memory research makes clear that there is no use in fighting the tide of forgetting that leaves some memories ashore even as it sweeps away — mercifully, at times — the rest.