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Book Review: The Mysteries and Quirks of Human Memory


Authors don’t get to choose what’s going on in the world when their books are published. More than a few luckless writers ended up with a publication date of Sept. 11, 2001, or perhaps Nov. 8, 2016, the day Donald Trump was elected.

But Charan Ranganath, the author of “Why We Remember: Unlocking Memory’s Power to Hold on to What Matters,”was more fortunate. His book went on sale last month, not long after the Department of Justice released a report describing President Joe Biden as an “elderly man with a poor memory” who, in interviews, was “struggling to remember events,” including the year that his son Beau died.

BOOK REVIEW “Why We Remember: Unlocking Memory’s Power to Hold on to What Matters,” by Charan Ranganath (Doubleday, 304 pages).

The special counsel’s report immediately became a topic of intense discussion — disputed by the White House, seized on by many Republicans, analyzed by media commentators, and satirized by late-night television hosts.

But for Ranganath, a psychologist and neuroscientist at the University of California, Davis, who for decades has been studying the workings of memory, the report’s release was a stroke of luck. His book, which dispels many widespread but wrongheaded assumptions about memory — including some to which that special counsel Robert K. Hur appears to subscribe — could easily have been written as a corrective response.

If Ranganath has a central message, it is that we are far too concerned about forgetting.

Memory does not work like a recording device, preserving everything we have heard, seen, said, and done. Not remembering names or exact dates; having no recollection of the details of a conversation; being unable to recall where you left your glasses or your keys; or watching movies you saw in the past as if you are seeing them for the first time — these are not the symptoms of a failing brain.

They are, on the contrary, signs that your brain is doing just what it was designed to do: prioritize and store important information and let nonessential facts and details slip away, a function that was essential to survival for our evolutionary ancestors. That task has become substantially more difficult with the steady bombardment of email, texts, social media, pop-up ads, and 24-hour news that most people contend with on a daily basis, and as a result, much more extraneous information is forgotten. Even a president might forget a thing or two.

But that doesn’t mean something is wrong. “The problem isn’t your memory, it’s that we have the wrong expectations for what memory is for in the first place,” Ranganath writes in his introduction, a theme that he returns to throughout the book. “Severe memory loss is undoubtedly debilitating, but our most typical complaints and worries around everyday forgetting are largely driven by deeply rooted misconceptions.”

Those misguided notions include the idea that memory is an archival repository of our life stories; that memories are fixed and unchangeable, and perhaps most of all, that our memories can always be trusted, when in fact they are eminently corruptible.

“Our most typical complaints and worries around everyday forgetting are largely driven by deeply rooted misconceptions.”

What scientists know about how memory works has increased significantly over the last decades. Ranganath early on introduces readers to a basic distinction between episodic memory, the ability to recall life events and experiences — where you were going and what you were feeling the day you left your wallet sitting on a bench in Central Park, for example — and semantic memory, the ability to recall factual information, like how many justices sit on the Supreme Court.

The difference was first proposed in 1972 by a University of Toronto professor, Endel Tulving, who took issue with the prevailing school of behaviorism, which held that memory was purely a matter of association. But a half-century of research, Ranganath writes, has backed Tulving up. Episodic memory, scientists have found, is largely mediated by the hippocampus, a small, seahorse-shaped structure deep in the brain, while semantic memory largely involves neural networks in the neocortex, the gray matter of the brain.

But studies — many of them using brain imaging techniques like functional fMRI, which measures blood flow — have made clear that other parts of the brain are also involved in the process of memory formation, storage, or retrieval. They include the prefrontal cortex; the group of neocortical areas known as the default mode network or DMN; the perirhinal cortex, and other parts of the limbic system, like the amygdala and the nucleus accumbens, as well as brain chemicals like dopamine and noradrenaline that mediate emotions and communications among a vast, interconnected network of neurons.

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Far from being static, Ranganath writes, memory, like the brain itself, is malleable, and constantly being updated. It can be shaped by where we are, what we are feeling, what other people say and do, and whether it is a negative or positive memory we are trying to recall. And though people often think about memory as having to do only with the past, Ranganath holds that this is misconceived: Memory also is intimately intertwined with the present and with the future.

“Only when we start to peek behind the veil of the ‘remembering self,’’ he writes, “do we get a glimpse of the pervasive role memory plays in every aspect of human experience and recognize it as a powerful force that can shape everything from our perceptions of reality to the choices and plans we make, to the people we interact with, and even to our identity.”

Ranganath is an astute and affable tour guide, peppering what might otherwise be a recitation of memory studies and their findings with personal anecdotes — the day he was captured by the “piercing blue eyes” of his future wife, as a college student sitting on the bed in a friend’s dorm room at the University of California, Berkeley, for example, or the disastrous paddleboarding trip he took with a colleague and how the story of their encounter morphed as they retold it later to others.

He also includes an abundance of references to rock and heavy metal bands, from Def Leppard to fIREHOSE. (In college, Ranganath played with a band called Plug In Drug, and, he writes, still sits in occasionally with Pavlov’s Dogz, a cover band made up of neuroscientists).

Though people often think about memory as having to do only with the past, Ranganath holds that this is misconceived: Memory also is intimately intertwined with the present and with the future.

“Why We Remember” ranges widely. Ranganath writes about the links between memory and imagination, about research on Alzheimer’s disease and post-traumatic stress disorder, about brain plasticity. He delves into the controversy over repressed memories and eyewitness testimony and recounts the 1906 case of Richard Ivens, who under pressure falsely confessed to having committed a brutal murder, and describes the techniques used by Scott Hagwood, four-time winner of the USA Memory Championship.

Some of what is covered in the book will be familiar to readers who’ve taken a course in experimental psychology, like the 19th-century work of Hermann Ebbinghaus, who memorized thousands of three-letter “trigrams,” or the case of the patient known as H.M., famous for his severe memory impairment, caused by experimental neurosurgery to treat his epilepsy.

To some, “Why We Remember” may seem too much like a textbook, full of researchers’ names and the details of experiments (the book includes 38 pages of footnotes and a 41-page bibliography). And it’s clear that Ranganath, like many scientists who undertake to book writing, has been encouraged to include personal details and stories that readers can relate to, and to offer some self-help tips. In this case, that includes telling readers how we “can seize the opportunity to play an active role in our remembering, freeing ourselves from the shackles of the past and instead using the past to guide us toward a better future.”

Yet Ranganath is the first to admit that what scientists know about memory pales in comparison to what is yet to be learned. “Science is not about having all the answers,” he writes. “It’s about asking better and more revealing questions. There is always going to be a missing piece of the puzzle. But searching for an answer forces us to see the world in new ways, challenging our most stubborn assumptions about who we are.”

Erica Goode, a science journalist, is a former reporter and editor at The New York Times and former managing editor of Inside Climate News.