title: Topography of Slow Sigma Power during Sleep is Associated with Processing Speed in Preschool Children.
abstract: Cognitive development is influenced by maturational changes in processing speed, a construct reflecting the rapidity of executing cognitive operations. Although cognitive ability and processing speed are linked to spindles and sigma power in the sleep electroencephalogram (EEG), little is known about such associations in early childhood, a time of major neuronal refinement. We calculated EEG power for slow (10-13 Hz) and fast (13.25-17 Hz) sigma power from all-night high-density electroencephalography (EEG) in a cross-sectional sample of healthy preschool children (n = 10, 4.3 ± 1.0 years). Processing speed was assessed as simple reaction time. On average, reaction time was 1409 ± 251 ms; slow sigma power was 4.0 ± 1.5 μV²; and fast sigma power was 0.9 ± 0.2 μV². Both slow and fast sigma power predominated over central areas. Only slow sigma power was correlated with processing speed in a large parietal electrode cluster (p < 0.05, r ranging from -0.6 to -0.8), such that greater power predicted faster reaction time. Our findings indicate regional correlates between sigma power and processing speed that are specific to early childhood and provide novel insights into the neurobiological features of the EEG that may underlie developing cognitive abilities.
authors.affiliation: Sleep and Development Laboratory, Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA. margaret.doucette@colorado.edu.
authors.forename: Margaret R
authors.initials: MR
authors.lastname: Doucette
authors.affiliation: Sleep and Development Laboratory, Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA. salome.kurth@colorado.edu.
authors.forename: Salome
authors.initials: S
authors.lastname: Kurth
authors.affiliation: Department of Psychology, University of Edinburgh, Edinburgh EH8 9JZ, UK. nicolas.chevalier@ed.ac.uk.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Chevalier
authors.affiliation: Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA. munakata@colorado.edu.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Munakata
authors.affiliation: Sleep and Development Laboratory, Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA. monique.lebourgeois@colorado.edu.
authors.forename: Monique K
authors.initials: MK
authors.lastname: LeBourgeois
keywords: cognition; early childhood; high density EEG; preschool children; processing speed; sigma power; sleep spindles