Study Objectives: A growing body of evidence suggests that sleep is critical for the processing and consolidation of emotional information into long-term memory. Previous research has indicated that emotional components of scenes particularly benefit from sleep in healthy groups, yet sleep dependent emotional memory processes remain unexplored in clinical cohorts, including those with obstructive sleep apnea (OSA).

Methods: In this study, a group of newly diagnosed OSA patients (n=26) and a matched group of healthy controls (n=24) encoded scenes with negative or neutral foreground objects placed on neutral backgrounds prior to a night of polysomnographically recorded sleep. In the morning they completed a recognition test in which objects and backgrounds were presented separately and one at a time.

Results: OSA patients have a deficit in both the overall gist and the specific recognition memory for the scenes. Impairment of gist recognition was across all elements of the scenes, both negative and neutral objects and backgrounds [main effect of group: F1, 48 = 13.5, p = 0.001], while specific recognition impairment was exclusively found for negative objects [t(48) = 2.0, p = .05]. Successful gist recognition correlated positively with sleep efficiency (p = 0.001) and REM sleep (p = 0.009), while successful specific memory recognition correlated only with REM sleep (p = 0.004).

Conclusions: Our findings indicate that fragmented sleep and reduced REM sleep, both hallmarks of OSA, significantly disrupt distinct memory processes for emotional content, which could alter emotional regulation and contribute to the high comorbid depressive symptoms in OSA.