I don't think I'll ever forget laying eyes on the cartoonish black-and-white paws that belonged to my now-seven-year-old dog. I was at a local shelter, standing in a room filled with adorable, adoptable puppies, but hers was the waggly tail that made me feel giddy. That moment is burned into my mind, which makes sense from a scientific perspective — plenty of research has shown that humans have a heightened memory for emotionally arousing experiences.
But I also have strangely vivid memories of other mundane, non-puppy-related details from my trip to the shelter. Why would this be? Well, according to a new NYU study published in Nature, people have an easier time remembering unremarkable moments when they immediately follow emotional ones.
When something (e.g., the sight of a new pet/best friend) throws us into a strong emotional state (e.g., one of total joy), critical memory-related brain networks light up, enabling us to revisit that experience for years to come. Now, NYU researchers have found that those networks stay lit up for an additional 10-30 minutes. And whatever goes on during that time frame stays with us, too. It's like an "emotional hangover," according to the study press release. (On a sidenote, this term wasn't used in the study itself.)
To assess the strength of people's memory for non-emotional experiences, researchers set up an experiment: One group of study volunteers viewed a series of emotionally arousing images, followed by a series of neutral images. A second group viewed the images in reverse order: non-emotional first, emotional second. During the image-viewing sessions, researchers measured volunteers' brain activity, using fMRI, and physiological arousal levels.
Six hours later, both groups were tested on their memory of the images — volunteers who'd viewed the emotional images first performed better. In this group, activity ramped up in and between brain regions involved in emotion-processing and memory formation, and stayed that way for over a half hour (in some cases). The same brain activity pattern was not observed in members of the other group, who'd viewed the non-emotional photos first.
The study adds to our knowledge of the ways emotional arousal can influence how we perceive, and later remember, what happens in our lives. But, there are plenty of unknowns to explore in further research. For example, it's unclear what sort of emotional experience is required to enhance memory. In the study, volunteers looked at gruesome images for more than 20 minutes. Would the volunteers have exhibited the same memory boost if they'd only viewed a handful of disturbing photos? It's also unclear how long an emotional hangover might last, study authors explained. Regardless, while adopting puppy after puppy is probably out of the question, you can go forth and binge whatever TV shows gives you the feels (or the giggles, or the willes). You're not wasting time, you're warming up your memory.