By Robby Berman — Fact checked by Catherine Carver, MPH
Our ability to remember life events declines as we age, particularly for people with memory impairment or diseases such as Alzheimer’s. A new study from researchers at the University of Toronto describes that some people may be able to successfully reinforce their memories through a smartphone-based app.
The app helps by mimicking the behavior of the brain’s hippocampus. Researchers believe that the hippocampus repeatedly replays memories to the rest of the brain at high speed to help stabilize them for long-term recall.
The app is called HippoCamera.
Researchers found that people who used the app for two weeks experienced a 56% increase in their ability to recall the details of events recorded with HippoCamera. People who used it for 70 consecutive days saw an 84% increase.
HippoCamera is available for Apple’s iPhone and iPad, but is not yet functional for non-research use. Its developers expect to open the app to the public soon. The study appears in PNAS.
Much of who we are as people has to do with our lifetime of memories, perhaps the most lasting possessions we acquire. These memories also constitute the experiences upon which we base the manner in which we interact with the world each day.
People with memory impairment have a harder time navigating the world, with a loss of confidence from an inability to recall how it works. In addition, a person may lose a critical aspect of their identity by forgetting part of who they have been, leading to a sense of isolation from family and friends.
While the HippoCamera helps people recall only those specific memories it has recorded, its value may be broader than that, said study lead author Dr. Chris Martin, a cognitive neuroscientist at Florida State University.
“If you can better recall a specific moment from your recent past, you will have a stronger mental bridge between your present and past self.”
Among its possible benefits, he said, may be the ability to deepen connections between the HippoCamera user and people who participated in recorded events, as the result of a renewed ability to recall and share experiences.
The study’s senior investigator is Prof. Morgan D. Barense, a cognitive neuropsychologist at the University of Toronto. She suggested that the app may foster new memory habits:
“We also hope that it will get people into the habit of focusing on their memories, and to understand that there are lots of simple things we can do to preserve our memories for the events of our lives.”
In one experiment, participants recorded five 24-second clips of everyday events each day for two weeks using HippoCamera. As they captured each event, they also recorded an eight-second audio description of its significance.
Individuals were instructed to replay six previously recorded events each day over a period of 2 weeks. They received reminders to do so from the app.
As a video played back, text briefly appeared onscreen stating how much time had elapsed since the event was recorded, along with its date.
The video then played at triple speed — imitating the hippocampus’ own high-speed playbacks — accompanied by the recorded description of the event played at normal speed.
The researchers conducted a second trial designed to better represent the real-world, self-guided use of the app. In this experiment, individuals recorded just one event each day, and replayed one event, for 10 weeks.
Immediately after both experiments, the researchers conducted memory tests in which participants viewed their clips as their brain activity was monitored using fMRI. The researchers compared their scores to baseline tests administered at the start of each experiment.
The scans revealed that as events were replayed, there was increased activity in the hippocampus, and that there was a positive correlation between the degree of this activity and the number of details a participant remembered.
Three months after each experiment, its participants were again tested as fMRI scans were performed. However, this time, they had no access to the app, relying strictly on their memories.
At these later tests, people in the first experiment scored a little better than they had immediately after app use, going from a 55.8% to a 58.9% improvement compared to their baseline scores.
Those in the second group, however, exhibited a decrease in scores, from an 83.8% improvement initially to a 56% score later on.
“Hippocampal replay,” said Prof. Barense, “is thought to underpin memory consolidation and make memories stable in the long term.”
“With HippoCamera, we are hoping to stand in or prompt hippocampal replay, so that memory for these events can be preserved,” she added.
Prof. Daniel L. Schacter, psychologist and researcher of cognitive neuroscience of memory at Harvard University, was not involved in the study.
He told us, however, that “[t]he science behind this application is solid — the investigators used a rigorous experimental design and analyses to support their claims, and to link the cognitive memory effects to neural changes in the hippocampus, a brain region that is known to play a key role in memory retrieval.”
Dr. Barense also noted that playback in HippoCamera is configured to be as evocative as possible, “so watching HippoCamera cues brings back memory for so much more than what is shown in the video.”
She said that, in addition to remembering details, participants recalled “emotions, who was there what happened next — all that extra information will flood back in as well.”
Participants told the researchers that the habits they built using HippoCamera mean “that they start to find little things in their life that they wouldn’t have appreciated before,” noted Dr. Barense.
In addition, said Prof. Schacter, although a person’s memory of events outside their HippoCamera recordings may remain uncertain, “enhanced recall of experiences that are reactivated using the app should make a meaningful difference in the life of a forgetful individual.”
This article originally appeared here and was republished with permission.