To download LearnBoost for Android, click here!



Recently, one of the things I’ve been interested in is how manipulating sleep can be used to affect cognitive performance. In the process of developing Sleep Boost (an app for enhancing slow waves during sleep), another interesting technique that I stumbled on to was targeted memory reactivation (TMR). Much like the slow-wave enhancement methods I previously talked about that have been used to improve memory, TMR uses sensory stimulation activated during deep sleep. The mechanism of action is rather different though: it works by “cuing” specific memories (typically by sound or smell), which enhances their ability to be recalled the next morning.

Why does cuing improve recall? The best answer is likely because one of the main functions of deep sleep is optimization of memory and strengthening of important memories. This function means that memories seem to be unusually “plastic” during this period—their strength can be altered to a significant degree by activating them, an effect that’s been investigated in improving vocabulary learning and enhancing the effects of counter-stereotype training.

In most cases, detection of deep sleep in studies is carried out with EEG. However, like in my previous app it’s theoretically possible to do the same thing using measures of body movement (more or less; it’s very difficult to distinguish REM from deep non-REM sleep using movement since both states involve little movement).

Therefore, I decided to write an app for implementing targeted memory reactivation, called Learn Boost. It’s available for free on the Google Play store and uses the verbal cues like the ones described in this study to reactivate memories.

Using LearnBoost requires first setting up a list of cues you want to use (ideally single words or phrases related to something you’ve recently learned) and placing the phone in your bed near your pillow. Unlike the previous Sleep Boost app, there is no manual calibration of the deep-sleep detection required—the algorithm will automatically calibrate itself during the first sleep cycle. Like Sleep Boost, it probably doesn’t work terribly well on memory foam mattresses or if there’s more than one person in the bed.

Please try out LearnBoost here, and let me know (here or on reddit if you have any comments or ideas!)