title: Learning and sleep-dependent consolidation of spatial and procedural memories are unaltered in young men under a fixed short sleep schedule.
abstract: To investigate if a fixed short sleep schedule impairs one of the main functions of sleep, which is to consolidate newly learned memories.
  
  
  
  Sixteen young men participated in two experimental conditions, each of which lasted for 3 consecutive days and nights in our laboratory: a short sleep schedule (4.25-h sleep opportunity per night) versus a normal sleep schedule (8.5h per night). In the evening after two experimental nights, participants learned locations of 15 card pairs (spatial memory task) and a procedural finger tapping sequence task. Post-sleep retrieval of both memory tasks was tested the next morning.
  
  
  
  The short sleep schedule, compared with the normal sleep schedule, considerably altered sleep characteristics, e.g. the proportion of time in slow-wave sleep increased across the three experimental nights. In contrast, neither learning in the evening of day 2, nor subsequent overnight memory consolidation (i.e. concerning the change in memory performance between pre-sleep learning on day 2 and post-sleep retrieval on day 3) differed between the normal and short sleep schedule conditions.
  
  
  
  Our findings suggest that learning in the evening and subsequent sleep-dependent consolidation of procedural and spatial memories are unaltered in young men living under a fixed short sleep schedule. Future studies are warranted to validate our findings in other groups (e.g. adolescents and older subjects) and after more prolonged chronic sleep loss paradigms.
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden. Electronic address: jonathan.cedernaes@neuro.uu.se.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Cedernaes
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden.
authors.forename: Filip
authors.initials: F
authors.lastname: Sand
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden.
authors.forename: Lisanne
authors.initials: L
authors.lastname: Liethof
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden.
authors.forename: Lauri
authors.initials: L
authors.lastname: Lampola
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden.
authors.forename: Sara
authors.initials: S
authors.lastname: Hassanzadeh
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden.
authors.forename: Emil K
authors.initials: EK
authors.lastname: Axelsson
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden.
authors.forename: Adine
authors.initials: A
authors.lastname: Yeganeh
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden.
authors.forename: Olof
authors.initials: O
authors.lastname: Ros
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden.
authors.forename: Jan-Erik
authors.initials: JE
authors.lastname: Broman
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden.
authors.forename: Helgi B
authors.initials: HB
authors.lastname: Schiöth
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden. Electronic address: christian.benedict@neuro.uu.se.
authors.forename: Christian
authors.initials: C
authors.lastname: Benedict
mesh_terms: D000328:Adult; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D000069077:Memory Consolidation / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000503:physiopathology*; D065852:Spatial Memory / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult
keywords: Procedural memory; Sleep duration; Sleep-dependent memory consolidation; Spatial memory