Related Experiment Video
Updated: Aug 7, 2026

Measuring Neural Mechanisms Underlying Sleep-Dependent Memory Consolidation During Naps in Early Childhood
Published on: October 2, 2019
Brief sleep after learning keeps emotional memories alive for years
Ullrich Wagner1, Manfred Hallschmid, Björn Rasch
1Department of Neuroendocrinology, Medical University of Lübeck, Lübeck, Germany. wagner@kfg.mu-luebeck.de
Background:
Sleep after learning supports memory consolidation. However, long-lasting memory effects of sleep have not yet been investigated. Postlearning sleep may be particularly involved in the long-term retention of emotional memories and could thereby contribute to the development of posttraumatic stress disorder (PTSD), a disease thought to result from overconsolidation of traumatic memories.
Methods:
Subjects (healthy men) who had learned neutral and emotional texts immediately before sleeping or remaining awake for the subsequent 3 hours were recontacted after 4 years for long-term memory assessment (forced-choice recognition test).
Results:
Sleep following learning compared with wakefulness enhanced memory for emotional texts after 4 years (p = .001). No such enhancement was observed for neutral texts (p = .571).
Conclusions:
Brief periods of sleep immediately following learning cause preservation of emotional memories over several years. Sleep deprivation in the immediate aftermath of traumatic events could be a promising therapeutic measure to prevent PTSD.
Related Concept Videos
Traumatic Memory
Higher Mental Functions of Brain: Learning and Memory
Chunking and Rehearsal in Sensory Memory
Long-Term Memory
Long-term memory can be categorized into two primary types: explicit and implicit memory. Explicit memory, also known as declarative memory, involves the conscious recollection of information that we deliberately try to remember, recall, and articulate. This type of memory encompasses specific facts, events, and...
Stages of Sleep
Before sleep begins, in wakefulness, the brain exhibits primarily beta waves, which are high in frequency and low in amplitude, indicating alertness...
Sleep-Wake Cycles
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
