Sleeping in a Brave New World: Opportunities for Improving Learning and Clinical Outcomes through Targeted Memory Reactivation

Abstract

Neuroscientific insights into learning and memory have mostly concerned input and output, but intervening processing during the time between acquisition and retrieval is also critical. Indeed, intervening memory reactivation may regulate memory longevity, and a growing body of evidence implicates sleep in changing memory storage. For example, subtle auditory stimulation can be used experimentally to selectively encourage memory reactivation during sleep, which thereby improves learning. Much remains to be elucidated about how learning depends on sleep. Nevertheless, this methodology for modifying memory storage during sleep offers new opportunities for reinforcing learning to enhance clinical outcomes in conjunction with therapies engaged during waking. A variety of such possibilities must now be carefully investigated. Likewise, brain rhythms can be entrained to enhance sleep functions, facilitating further progress in understanding the neurophysiological basis of memory processing during sleep. Ultimately, empirical evidence may reveal the extent to which the way we behave when awake is a function of what our brains do when we are asleep. Through such research efforts, an advanced understanding of memory and sleep may allow us to both make better use of our time asleep and take steps toward better health.

Keywords: Learning; memory reactivation; psychotherapy; rehabilitation; sleep.

Conflict of interest statement

Declaration of Conflicting Interests The author declared no conflicts of interest with respect to the authorship or the publication of this article.

Figures

Figure 1

A. People learned to play two 12-note melodies on a keyboard in sync with moving circles. To produce the correct notes, the correct key had to be hit at precisely the correct time (as in the Guitar Herovideogame). After training, average performance accuracy was 77% correct responses. Following a nap when one melody was played during slow-wave sleep, a greater performance improvement was observed for that melody compared to the other melody (Antony et al., 2012).B. Counter-stereotype training produced a reduction in implicit social bias for race or gender as measured using the Implicit Association Test. After this training, standardized implicit bias scores were reduced by an average of 0.224. Then, following a nap when the sound associated with one type of bias training was played during slow-wave sleep, a greater change in bias reduction was observed for that bias compared to the other bias. A positive change score indicates a further reduction in bias from the level reached after training, whereas a negative change score, as shown for the uncued bias, indicates a return in the direction of the typical racial or gender bias (Hu et al., 2015).