Sleep spindle activity and cognitive performance in healthy children.

STUDY OBJECTIVES: To investigate the association between indices of sleep spindle activity and cognitive performance in a sample of healthy children. DESIGN: Correlational. Intelligence (Stanford-Binet) and neurocognitive functioning (NEPSY) were assessed, with sleep variables being measured during overnight polysomnography. SETTING: Hospital sleep laboratory. PARTICIPANTS: Twenty-seven healthy children (mean age 8.19 y; 14 female, 13 male). INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Participants underwent a single night of overnight polysomnography after completing measures of intelligence and neurocognitive functioning. Sleep spindles were visually identified by an experienced sleep scoring technician and separated algorithmically into fast (> 13 Hz) and slow spindle (< 13 Hz) categories. The number of fast spindles was significantly correlated with narrative memory (r(s) = 0.38) and sensorimotor functioning (-0.43). Mean central frequency of spindles was also significantly correlated with sensorimotor functioning (-0.41), planning ability (-0.41), and working memory (-0.54). CONCLUSIONS: Basal sleep spindle activity is associated with different aspects of cognitive performance in children. To the extent that these associations in a pediatric population are different from what is known in adult sleep may play an important role in development.