There is a growing body of research that indicates that technology, and particularly smartphones, may affect what moments will be encoded into our memories.

Our memory could end up impoverished as a result, says Henkel. Not that our memory processes themselves become weaker, but rather, that we have less to remember in the first place.

I remember, when I was fourteen years old, spending a few weeks at my aunt’s house in Humboldt County, CA, where my evenings were consumed by hours spent chatting with friends on AOL Instant Messenger. Some of those friendships would go on to become meaningful, defining aspects of my time spent in high school, while others faded away, united by little more than time zones and a similar taste in music.

But there is one thing all these online conversations had in common: I remember almost none of them.

I have no idea what we talked about. I scarcely remember anyone’s screen names, or even my own. What I do remember about that trip to Humboldt County was hanging out and laughing with my cousin, going out to the family’s favorite Mexican restaurant, hiking in the redwoods, and the evenings I spent offline, making collages from old magazines on my cousin’s bedroom floor.

Those forgotten IM nights may be an inkling of what is to come for the memories of millennials, Generation Z, and others younger than that, all raised essentially online and on their phones. For a number of reasons, researchers hypothesize, the time we spend interacting with technology and social media may be affecting how, and what, we remember.

It’s difficult to say with absolute certainty just how much technology will impact people’s memories in the long term; after all, the internet is only 29 years old. Its widespread adoption in the form of smartphones and social media is even younger, and historically speaking, the change it’s wrought upon society is unique.

But there is a growing body of research that indicates that technology, and particularly smartphones, may affect what moments will be encoded into our memories and what, years later, even a photo or a social media post won’t be able to resurface.

“If you’re not paying attention to it, you’re not going to be able to remember it. You’re not going to be able to encode that memory if you never actually have the experience,” says Adrian Ward, an assistant professor of marketing at the University of Texas, Austin who has studied how technology affects attention and memory. “So things that you do in that moment that take you out of that experience will certainly prevent your ability to form that memory just because you’re not noticing it.”

In a 2013 landmark study, researchers had students go to a museum. One group of students was given cameras and instructed to photograph the art they looked at, while the other was instructed to merely observe the art. The group that photographed the art remembered less about the objects they photographed and the objects’ locations in the museum than those who had been told to just look. (Though the study participants used digital cameras, it’s likely that smartphone cameras would have the same impact.)

However, when the participants with the cameras zoomed in on the art (for example, if they took a photograph of the little dog in a painting instead of the entire painting), they retained better memories of the entire artwork compared to when they photographed the whole thing. The study author, Linda Henkel, theorized that the increased attention paid to the art of which students took zoomed-in photos helped strengthen their memories of the rest of the artwork. But when students took photographs of the entire object, they subconsciously depended upon the camera to “remember” it for them.

Henkel, a psychology professor at Fairfield University in Connecticut, dubbed this the “photo-taking impairment effect” — the act of photographing diverts the attention of the photographer, as well as acts like an external memory bank. The camera distracts you from your surroundings and acts as a sort of memory crutch, training you not to remember things on your own because you have the camera to rely on remembering it for you.

Another study from 2018 went even further. The researchers wanted to know if the inability to save the photos made a difference in participants’ memories. Initially, the researchers speculated that making the photos inaccessible, either by requiring that participants delete them or having them post the photos to Snapchat (which deletes photos automatically after 24 hours) would eliminate the photo-impairment effect, since the participants wouldn’t be able to rely upon the photos later to remember what they saw.

But to their surprise, the researchers found that any condition in which participants took photos, regardless of whether they’d have access to them later or not, impacted their ability to remember what they’d seen. This, the researchers theorized, meant that it was the act of photography itself that caused participants not to pay attention to what they were looking at.

Taking photos can also impact the accuracy of memories, and even make people think they experienced things they didn’t. Henkel told me about an experiment from the Harvard memory researcher Daniel Schacter, in which he challenges Alan Alda, host of the PBS show Scientific American Frontiers, to remember what happens at a picnic. First, Alda and Schacter watch two people having a picnic. Two days later, Schacter shows Alda a series of photographs of the picnic (some of which depicted picnic scenes that Alda had not actually witnessed), then quizzes him on the presence of certain items.

Alda misremembered what he’d seen at the picnic, thinking he’d seen one picnic-goer filing her nails when that had only been in a photograph and he hadn’t actually seen it happen.

“The act of looking at photos actively shapes our memories,” says Henkel. “[Photos] are not reality; they are revisions of reality. And photos are only one interpretation of reality.”

Those who chronically Instagram vacations or nights out might be especially prone to this effect. A group vacation photo post with an image of a landmark your travel partners had visited while you chilled at the hotel may cause you to think you’d actually been there when you hadn’t. And a picture of you and your friends at dinner in which your close friend was in the restroom at the time the photo was taken might lead you to forget, when you revisit the post a couple years later, that she had attended the dinner.

Things get even hairier when you take a photo with the intent to post it online. 2018 research published in the Journal of Consumer Research found that taking a picture for social media takes away from your enjoyment of the experience because you’re more focused on how someone is going to react to your picture than you are on your surroundings.

Focusing on the digital world rather than the real world can also have an impact on memory, says Henkel, because your attention is diverted away from the physical world, with its tangible, memory-sparking smells, sounds, and sights, and toward a distant, imaginary audience devoid of these “context cues” that help you remember.

“The things that tend to lead to detailed, long-term memories are rich in sensory perceptual cues, contextual cues, affective responses, what your thoughts were, how you reacted, the feelings that they made,” says Henkel. “The digital version of that is often lacking the richness of the [real world]. When this generation of teenagers is 50 years old and you ask them, ‘tell me about some really important things or memorable things from your teen years,’ they’re probably not going to say, oh, that time my friend posted a picture and I laughed at it.’”

Our memory could end up impoverished as a result, says Henkel. Not that our memory processes themselves become weaker, but, rather, that we have less to remember in the first place.

But it’s not all bad, according to Judith Danovitch, an associate professor of psychological and brain sciences at the University of Louisville in Kentucky. While heavy internet use may encourage people to depend on the internet for information rather than retaining that information in their own brains, “by ‘freeing up’ this cognitive space, we might become better at synthesizing information or thinking creatively, which might also have benefits for long-term memory,” she says.

And there are things you can do to help protect your memory that don’t include swearing off your smartphone forever. Photos will spark your memory much better, says Henkel, if a small number of them are curated into an album. This more manageable collection of photos will increase the chances you’ll engage with them on a meaningful basis later on; well-chosen photos will spark further memories of an event that, without that photo, you may have forgotten.