title: Motor sequence consolidation: constrained by critical time windows or competing components.
abstract: Skill improvements may develop between practice sessions during memory consolidation. Skill enhancement within an egocentric coordinate frame develops over wake, whereas skill enhancement in an allocentric coordinate frame develops over a night of sleep. We tested whether both types of improvement could develop over two different 24-h intervals: 8 am to 8 am or from 8 pm to 8 pm. We found that for each 24 h interval, only one type of skill improvement was seen. Despite passing through wake and a night of sleep participants only showed skill improvements commensurate with either a night of sleep or a day awake. The nature of the off-line skill enhancement was determined by when consolidation occurred within the normal sleep-wake cycle. We conclude that motor sequence consolidation is constrained either by having critical time windows or by a competitive interaction in which improvements within one co-ordinate frame actively block improvements from developing in the alternative co-ordinate frame.
authors.affiliation: Center for Non-Invasive Brain Stimulation, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Cohen
authors.forename: Edwin M
authors.initials: EM
authors.lastname: Robertson
mesh_terms: D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology*; D003463:Cues; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006225:Hand / Q000502:physiology; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D008568:Memory / Q000502:physiology; D009048:Motor Skills / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D010809:Physical Fitness / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012890:Sleep / Q000502:physiology; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology