Rapid eye movement fragmentation, not slow‐wave sleep, predicts neutral declarative memory consolidation in posttraumatic stress disorder

Abstract

Individuals diagnosed with posttraumatic stress disorder (PTSD) experience disruption at both slow‐wave sleep (SWS) and rapid‐eye movement (REM) sleep stages and demonstrate marked memory impairment. A small group of studies suggests that, within the disorder, there is a mechanistic relation between these sleep and memory impairments. This study sought to extend that literature by examining whether, in PTSD‐diagnosed individuals, memory‐retention deficits are present after a sleep‐filled (but not after a wake‐filled) delay (i.e., whether memory deficits can be traced to interruptions of sleep‐dependent memory consolidation). Moreover, we investigated whether SWS‐ or REM‐based disturbances, or both, contribute to retention deficits. We recruited participants into three groups: PTSD (n = 21), trauma‐exposed non‐PTSD (TE; n = 19) and healthy control (HC; n = 20). Using a crossover design, we assessed memory recall before and after an 8‐hr period of polysomnography‐monitored sleep and an 8‐hr period of regular waking activity. PTSD‐diagnosed participants retained less information than controls over the sleep‐filled (but not wake‐filled) delay. Furthermore, increased REM fragmentation predicted postsleep memory retention in PTSD‐diagnosed individuals only. No SWS parameter was associated with or predictive of the amount of information retained postsleep. We conclude that specific REM‐related changes in PTSD‐diagnosed individuals affected sleep‐dependent neutral declarative memory consolidation. Generally, these findings extend the literature suggesting that the co‐occurrence of sleep and memory difficulties in PTSD is not accidental, but that these two symptom clusters are meaningfully related. Specifically, the study illustrates that subtle REM‐related disruptions contribute most strongly to memory impairment in PTSD.

Eight-Section Brocade Exercises Improve the Sleep Quality and Memory Consolidation and Cardiopulmonary Function of Older Adults With Atrial Fibrillation-Associated Stroke

“…Sleep plays an irreplaceable role in the process of consolidating declarative memory. Different ideas are available for the mechanism by which sleep reinforces declarative memory, suggesting that the problem still requires further exploration (Cellini et al, 2019b; Cousins and Fernandez, 2019; Lipinska and Thomas, 2019).…”

The Interaction of REM Fragmentation and Night-Time Arousal Modulates Sleep-Dependent Emotional Memory Consolidation

“…This cross-sectional quasi-experimental study was part of a larger research program emerging from doctoral work produced by the first author (Lipinska, 2017) investigating relations between cognition, affect, and sleep in PTSD, TE, and HC groups (Lipinska and Thomas, 2017, 2019; Breen et al, 2019).…”

Applied cognitive science in South Africa.

“…A small, yet consistent, vein of research has focused on studying the cognitive and emotion-related effects of sleep disruption consequent on environmental (e.g., car accident) and interpersonal (e.g., sexual assault) trauma. Individuals tend to respond in hyperaroused manner to trauma, and their sleep is extremely fragmented (Lipinska & Thomas, 2019). Indeed, this association is strongest for posttraumatic stress disorder-diagnosed individuals who experience significant disturbances in their home environments (van Wyk et al, 2016).…”