Authors:Péter Simor, Zsófia Zavecz, Eszter Csábi, Pálma Benedek, Karolina Janacsek, Ferenc Gombos, and Dezső Németh
Sleep-disordered breathing (SDB) is a prevalent sleep disorder among young children and is associated with daytime impairments, such as behavioral dysregulation, affective symptoms, and reduced cognitive performance. Microstructural changes of non-rapid eye movement sleep, particularly the reduction of slow frequency oscillations during slow-wave sleep (SWS) might be associated with impaired learning among children with SDB. In this study, we investigated the associations between learning capacity, overnight memory retention, and post-learning, spectral power density of SWS within a clinical sample of children (n = 27) with SDB. Participants performed a declarative (the “War of the Ghosts”) and a non-declarative (the “Alternating Serial Reaction Time”) memory task at night, before their clinical (nighttime polysomnographic) evaluation. Memory retention was assessed in the morning. Overnight changes in performance in the declarative and non-declarative task were not related to relative spectral power measures of SWS. Nevertheless, declarative learning capacity was positively correlated with relative delta (1.25–4 Hz) and negatively with relative theta (4.25–8 Hz) power. Although statistical learning was not associated with spectral power, general skill learning was positively associated with delta and negatively associated with theta power. Associations in case of declarative learning remained significant beyond the influence of age; however, in case of general skill learning the associations with delta and theta power were explained by age. These findings indicate that among children with SDB, oscillations within the delta and theta band during SWS are associated with declarative learning capacity, but are independent from non-declarative, statistical learning.