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A Math Function Describes How Whole Societies Remember—and Forget

A Neruda masterpiece—and a bi-exponential curve—define the dynamics of the fast then slow fade of our greatest collective sorrows and joys


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In a paper that deftly bridges the divide between the humanities and the sciences—C. P. Snow’s much-vaunted two cultures—researchers from the MIT Media Lab document the underlying dynamics of collective attention and memory, traced as a bi-exponential curve (a steep drop followed by a slow decline over time).

The paper published on December 10 in Nature Human Behavior begins with a quotation from one of Pablo Neruda’s most famous poems, “Poema 20,” contrasting the vivid but often short-lived emotion of intense romantic love and its gradual fading from memory as the years pass: “Love is so short, forgetting is so long.” The dynamics of this process, the researchers contend, parallel precisely the attention a society devotes to its most memorable events (whether the Watson–Crick paper on the structure of DNA or Michael Jackson’s Thriller video). 

Gary Stix, the neuroscience and psychology editor for Scientific American, edits and reports on emerging advances that have propelled brain science to the forefront of the biological sciences. Stix has edited or written cover stories, feature articles and news on diverse topics, ranging from what happens in the brain when a person is immersed in thought to the impact of brain implant technology that alleviates mood disorders like depression. Before taking over the neuroscience beat, Stix, as Scientific American's special projects editor, oversaw the magazine's annual single-topic special issues, conceiving of and producing issues on Einstein, Darwin, climate change and nanotechnology. One special issue he edited on the topic of time in all of its manifestations won a National Magazine Award. Stix is the author with his wife Miriam Lacob of a technology primer called Who Gives a Gigabyte: A Survival Guide to the Technologically Perplexed.

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