title: Sleep spindles and intelligence: evidence for a sexual dimorphism.
abstract: Sleep spindles are thalamocortical oscillations in nonrapid eye movement sleep, which play an important role in sleep-related neuroplasticity and offline information processing. Sleep spindle features are stable within and vary between individuals, with, for example, females having a higher number of spindles and higher spindle density than males. Sleep spindles have been associated with learning potential and intelligence; however, the details of this relationship have not been fully clarified yet. In a sample of 160 adult human subjects with a broad IQ range, we investigated the relationship between sleep spindle parameters and intelligence. In females, we found a positive age-corrected association between intelligence and fast sleep spindle amplitude in central and frontal derivations and a positive association between intelligence and slow sleep spindle duration in all except one derivation. In males, a negative association between intelligence and fast spindle density in posterior regions was found. Effects were continuous over the entire IQ range. Our results demonstrate that, although there is an association between sleep spindle parameters and intellectual performance, these effects are more modest than previously reported and mainly present in females. This supports the view that intelligence does not rely on a single neural framework, and stronger neural connectivity manifesting in increased thalamocortical oscillations in sleep is one particular mechanism typical for females but not males.
authors.affiliation: Institute of Behavioral Science, Semmelweis University, H-1089 Budapest, Hungary.
authors.forename: Péter P
authors.initials: PP
authors.lastname: Ujma
authors.affiliation: Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, 6525 EN Nijmegen, The Netherlands.
authors.forename: Boris Nikolai
authors.initials: BN
authors.lastname: Konrad
authors.affiliation: Centre for Cognitive and Neural Systems, University of Edinburgh, EH8 9JZ Edinburgh, United Kingdom.
authors.forename: Lisa
authors.initials: L
authors.lastname: Genzel
authors.affiliation: Max Planck Institute of Psychiatry, 80804 Munich, Germany.
authors.forename: Annabell
authors.initials: A
authors.lastname: Bleifuss
authors.affiliation: Department of Cognitive Sciences, Budapest University of Technology and Economics, 1111 Budapest, Hungary, Nyírö Gyula Hospital, National Institute of Psychiatry and Addictions, H-1135 Budapest, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Simor
authors.affiliation: Institute of Behavioral Science, Semmelweis University, H-1089 Budapest, Hungary.
authors.forename: Adrián
authors.initials: A
authors.lastname: Pótári
authors.affiliation: Institute of Behavioral Science, Semmelweis University, H-1089 Budapest, Hungary.
authors.forename: János
authors.initials: J
authors.lastname: Körmendi
authors.affiliation: Department of General Psychology, Pázmány Péter Catholic University, H-1088 Budapest, Hungary, and.
authors.forename: Ferenc
authors.initials: F
authors.lastname: Gombos
authors.affiliation: Max Planck Institute of Psychiatry, 80804 Munich, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Steiger
authors.affiliation: Institute of Behavioral Science, Semmelweis University, H-1089 Budapest, Hungary, Department of General Psychology, Pázmány Péter Catholic University, H-1088 Budapest, Hungary, and.
authors.forename: Róbert
authors.identifier: http://orcid.org/0000-0002-7255-0541
authors.initials: R
authors.lastname: Bódizs
authors.affiliation: Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, 6525 EN Nijmegen, The Netherlands, Max Planck Institute of Psychiatry, 80804 Munich, Germany, dresler@mpipsykl.mpg.de.
authors.forename: Martin
authors.identifier: http://orcid.org/0000-0001-7441-3818
authors.initials: M
authors.lastname: Dresler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology; D058256:Brain Waves / Q000502:physiology*; D005260:Female; D006801:Humans; D007360:Intelligence / Q000502:physiology*; D007361:Intelligence Tests; D008297:Male; D008875:Middle Aged; D012727:Sex Characteristics; D012894:Sleep Stages / Q000502:physiology*; D055815:Young Adult
keywords: intelligence; memory; sex; sleep; sleep spindles