Habitual night waking associates with dynamics of waking cortical theta power in infancy

The implications of the substantial individual differences in infant sleep for early brain development remains unclear. Here, we examined whether night sleep quality relates to daytime brain activity, operationalised through measures of EEG theta power and its dynamic modulation, which have been previously linked to later cognitive development (Braithwaite et al., 2020, Jones et al., 2020). For this longitudinal study 76 typically developing infants were studied (age: 4-14 months, 166 individual study visits) over the course of 6 months with 1, 2, 3, or 4 lab visits. Habitual sleep was measured with a 7-day sleep diary and actigraphy, and the BISQ. 20-channel EEG was recorded while infants watched multiple rounds of videos of women singing nursery rhymes; oscillatory power in the theta band was extracted. Key metrics were average theta across stimuli, and the slope of change in theta within the first novel movie. Both objective and subjective sleep assessment methods showed a relationship between more night waking, and higher overall theta power and reduced dynamic modulation of theta over the course of the novel video stimuli. These results may indicate altered learning and consolidation in infants with more disrupted night sleep, which may have implications for cognitive development

Damage progression by the element-failure method (EFM) and strain invariant failure theory (SIFT)

10.1016/j.compscitech.2004.10.022Composites Science and Technology656935-944CSTC