Smartphones are teaching us how to supercharge our memory

Memories don’t follow a straight, linear path, even though we often recall them like tidy stories. Researchers are now embracing this complexity, using smartphones to explore how memories shift over time, how they become richer or fade, and how we might intentionally strengthen them. 

These digital tools are allowing scientists to track real-life experiences in ways that lab studies can’t, revealing how actions like trying something new, replaying moments before sleep, or feeling strong emotions may enhance our memory.

These insights are being shared at the annual meeting of the Cognitive Neuroscience Society (CNS), where researchers are highlighting a range of smartphone-based studies that explore how memory is shaped by daily life. 

“Smartphones are an incredible tool for understanding patterns of feelings, behavior, and experiences in daily life, and how different types of everyday events stay with us in memory,” said Elizabeth Goldfarb from Yale University, who is chairing a session on the topic. 

“Real experiences have so much more salience and self-relevance than anything I can generate in the lab, and being able to quantify how people remember those events is very exciting.”

Sleep, dreams, and the timing of memory

One line of research being presented comes from Morgan Barense at the University of Toronto, who is examining how sleep and dreams affect memory retention. This work emerged unexpectedly, when a previous study showed that memory recall was significantly affected by when material was reviewed in relation to sleep. 

“We found that the timing of when someone first reviews material relative to sleep had an enormous effect on how well they later remembered it,” Barense said. 

“The effect was so striking that I initially didn’t believe it. That discovery made me realize that sleep is something all memory scientists should be paying close attention to.”

Barense’s team, led by graduate student Nelly Matorina, developed a smartphone app called HippoCamera to test how a night of sleep impacts memories from the day before. 

Memories following sleep are more vivid

Participants recorded two events each day – one in the morning, one in the evening – for two weeks. The researchers then tested recall after 12-hour intervals, comparing the effects of sleep versus wakefulness. 

Their earlier findings were confirmed. “Memories following sleep were more vivid, felt temporally closer, and were easier to recall, suggesting that a single night of sleep helps preserve the richness of autobiographical memory,” Barense explained.

Participants also recorded dreams and identified any that related to events captured with the app. “Interestingly, memories that were dreamt about were also rated as feeling temporally closer and were more likely to be recalled from a first-person perspective,” she added.

The team followed up by testing those same memories a year later to see how they changed, particularly in relation to the event’s location. 

“Our pattern of results suggests that the link between an event and its location may initially weaken after a night’s sleep to allow for memory reorganization, but over the long term, a year later, our memory is strongly connected to where it took place,” Matorina said.

Smartphones improve memory research 

While studying memory outside the lab comes with challenges, Barense sees great value in this approach. 

“Real-world data collection introduces variability that is difficult to control, and tracking sleep and memory over time requires careful methodological design,” she said. 

“However, these challenges are also what make smartphone-based research so promising – it allows us to move beyond artificial settings and study memory as it naturally unfolds in daily life.”

Looking ahead, Barense’s team will partner with Ken Paller’s lab at Northwestern University to see if memory retention can be boosted during sleep. They plan to combine HippoCamera with targeted memory reactivation, which uses sound cues tied to events and plays them during specific sleep stages. 

“While our previous work has shown that HippoCamera strengthens autobiographical memory in older adults, we believe that incorporating sleep-based memory reactivation will further amplify its benefits,” Barense said.

Smartphone app tests recall

Lila Davachi of Columbia University is also using smartphone-based research to explore memory, inspired by the mental and emotional effects of the pandemic. 

“The lab had already published several papers on the impact of context representations on associative memory and here we all were sitting in our homes, meeting on Zoom, with very little change in our contexts,” she said. 

“It was natural to wonder how this was going to impact our long-term memories and, perhaps by consequence, our mental health.”

Davachi and her team used a “daily diary” smartphone app, asking participants to report and categorize daily events over two weeks as “novel,” “routine,” or “periodic.” Two weeks later, they tested recall. 

With the help of artificial intelligence to analyze responses, the researchers found that novel events were remembered with greater vividness and detail. 

“Perhaps more exciting, we found that routine and periodic events that happened on the same day as a novel event were also better remembered than routine and periodic events that took place on days with less novelty,” Davachi explained. “This suggests a penumbra-like effect of novelty.”

This effect hints at the value of “experiential diversity” in strengthening memory. By mixing up daily routines with new experiences, people might be able to enhance not just specific memories but their overall ability to recall an entire day. 

“Being able to sample and record data from individuals in the real world, along with the use of AI-based large language models to help us analyze large amounts of complex data, is a solid stepping stone,” Davachi said.

Exploring the role of emotion and addiction

Goldfarb is also using smartphones to investigate how people remember emotionally intense experiences, particularly in the context of substance use. In one study, she is examining the role of memory in alcohol addiction. 

Memory is an important factor in addiction, since, for instance, someone can’t relapse in a place where they used to drink if they have no memories of drinking there. “Yet we know very little about what people remember about their time drinking that drives this behavior,” Goldfarb said.

Using smartphone recordings, her team is able to compare real-life memories of drinking events with patterns seen in lab studies. 

“We’re uncovering some similarities with what we measure in the lab, which is great for establishing ecological validity,” she said. However, these real-world observations are also revealing new insights. 

“We are seeing that people are more likely to link different parts of a positive event together in memory,” she said. “As a researcher, the effects of real emotions are so much stronger than what we can create in the lab.”

Goldfarb believes this emerging body of work – from dreams to novelty to emotions – is opening new doors in memory research. As she concludes, these new tools and findings are a significant step forward in helping people build stronger and more detailed memories.

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