title: The function of the sleep spindle: a physiological index of intelligence and a mechanism for sleep-dependent memory consolidation.
abstract: Until recently, the electrophysiological mechanisms involved in strengthening new memories into a more permanent form during sleep have been largely unknown. The sleep spindle is an event in the electroencephalogram (EEG) characterizing Stage 2 sleep. Sleep spindles may reflect, at the electrophysiological level, an ideal mechanism for inducing long-term synaptic changes in the neocortex. Recent evidence suggests the spindle is highly correlated with tests of intellectual ability (e.g.; IQ tests) and may serve as a physiological index of intelligence. Further, spindles increase in number and duration in sleep following new learning and are correlated with performance improvements. Spindle density and sigma (14-16Hz) spectral power have been found to be positively correlated with performance following a daytime nap, and animal studies suggest the spindle is involved in a hippocampal-neocortical dialogue necessary for memory consolidation. The findings reviewed here collectively provide a compelling body of evidence that the function of the sleep spindle is related to intellectual ability and memory consolidation.
authors.affiliation: University of Montreal, Montreal, Quebec, Canada, H3W 1W5. stuart.fogel@criugm.qc.ca
authors.forename: Stuart M
authors.initials: SM
authors.lastname: Fogel
authors.forename: Carlyle T
authors.initials: CT
authors.lastname: Smith
mesh_terms: D000818:Animals; D001931:Brain Mapping; D058256:Brain Waves / Q000502:physiology*; D004569:Electroencephalography; D006801:Humans; D007360:Intelligence / Q000502:physiology*; D007858:Learning / Q000502:physiology; D008568:Memory / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology