Odor cueing during sleep improves consolidation of a history lesson in a school setting

Abstract

Sleep is a key factor in memory consolidation. During sleep, information is reactivated, transferred, and redistributed to neocortical areas, thus favoring memory consolidation and integration. Although these reactivations occur spontaneously, they can also be induced using external cues, such as sound or odor cues, linked to the acquired information. Hence, targeted memory reactivation during sleep represents an advantageous tool for improving memory consolidation in real-life settings. In this study, our goal was to improve the consolidation of complex information such as that of a history lesson, using a school study session in the presence of an odor, and a reactivation round while sleeping at home on the same night of the acquisition, without using additional study sessions. We found that complex information can be associated with an odor in the classroom and that one session of reactivation during the first night of sleep in the students’ houses improves its consolidation. These results bring new evidence for the implementation of reactivation during sleep in real-life settings.

Odor cueing of declarative memories during sleep enhances coordinated spindles and slow oscillations

“…Since its initial demonstration 4 , the beneficial effect of memory cueing using odors has been shown for creativity tasks 26 , fear extinction 16 , declarative memory in a real-life setting 27,28 .…”

“…Since its initial demonstration 4 , the beneficial effect of memory cueing using odors has been shown for creativity tasks 26 , fear extinction 16 , declarative memory in a real-life setting 27,28 . The beneficial effect of cueing on memory has been shown to be odor-specific 15,29 , can be expressed unilaterally in the brain 14 , and is protected against interference when applied during sleep 5 , 29–31 .…”

Reap while you sleep: consolidation of memories differs by how they were sown

“…Our understanding about the mechanisms through which TMR impacts cognition has expanded substantially since its resurgence after the publication of Rasch et al (2007) 15 years ago, and it has recently been shown to support learning in applied settings (Gao et al, 2020;Neumann et al, 2020;Vidal et al, 2022). However, real-world memories are often complex, and it is therefore important to understand the role of sleep reactivation in supporting their retrieval.…”

“…We designate paradigms like the latter experiment as "simple", despite there being some variation within them (Box 1). While TMR experiments in real-world settings are scant (though see Gao et al, 2020;Neumann et al, 2020;Vidal et al, 2022), recent experiments have made inroads into how reactivation drives memory benefits and impairments in complex situations. We will review these findings and argue that an underlying theme is that consolidation trajectories are determined by the specifics of the learning experience.…”

Reap while you sleep: Consolidation of memories differs by how they were sown

“…We designate paradigms like the latter experiment as “simple,” despite there being some variation within them (Box 1). While TMR experiments in real‐world settings are scant (though see Gao et al, 2020; Knötzele et al, 2023; Neumann et al, 2020; Vidal et al, 2022), recent experiments have made inroads into how reactivation drives memory benefits and impairments in complex situations. We will review these findings and argue that an underlying theme is that the specifics of the learning experience determine the consolidation trajectories of associated memories, which we refer to as the consolidation trajectory hypothesis.…”