A new study from Canadian scientists has assessed a smartphone-based app which can reinforce memories of life events – and found it increased ability to recall details by 56-84%.
Researchers at the University of Toronto, whose study is published in PNAS, explained the app is designed to benefit people with memory impairment by imitating the function of the brain’s hippocampus as it helps ‘consolidate’ memories – scientists believe the hippocampus repeatedly replays memories to the rest of the brain at high speed to help stabilise them for long-term recall.
The app, called HippoCamera, involves recording life events and replaying them to ‘lock them in’ as memories: people who used the app for 2 weeks experienced a 56% increase in ability to recall details of events recorded; and those who used it for 70 consecutive achieved an 84%increase.
In one experiment, participants recorded 5x 24-second clips of everyday events for 2 weeks; as they captured each event, they also recorded an 8-second audio description of its significance. Individuals were instructed to replay 6 previously recorded events each day for 2 weeks and 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 as recorded, plus its date. The video then replayed at triple speed (imitating the hippocampus’ own high-speed playbacks) accompanied by the recorded description of the event played at normal speed.
In a second experiment, individuals recorded 1 event each day, and replayed 1 event for 10 weeks.
Immediately after both experiments, researchers conducted memory tests – participants viewed their clips while brain activity was monitored via MRI – and compared scores to baseline tests from the start of each experiment.
The scans revealed that as events were replayed, there was increased activity in the hippocampus – and a positive correlation between degree of activity and number of details remembered.
Three months after each experiment, participants were again tested as MRI scans were performed; but this time they had no access to the app, replying strictly on their memories.
People in the first experiment scored marginally better than immediately after app use, going from 55.8% to 58.9% improvement compared to baseline scores; but those in the second experiment showed a decrease in scores from an 83.8% improvement initially to a 56% score later on.
Study senior investigator Professor Morgan Barense told medicalnewstoday.com: ‘Hippocampal replay is thought to underpin memory consolidation and make memories stable in the long term. With HippoCamera, we are hoping to stand in for or prompt hippocampal replay, so memory for these events can be preserved.’
She noted 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.’
And in addition to remembering details, participants recalled ‘emotions, who was there, what happened next – all that extra information will flood back in as well’.
