Sleep contribution to motor memory consolidation: a motor imagery study.
OBJECTIVE
Sleep is known to enhance performance following physical practice (PP) of a new sequence of movements. Apart from a pilot study, it is still unknown whether a similar sleep-dependent consolidation effect can be observed following motor imagery (MI) and whether this mnemonic process is related to MI speed.


METHODS
Counterbalanced within-subject design.


METHODS
The laboratory.


METHODS
Thirty-two participants.


METHODS
PP, real-time MI, fast MI, and NoSleep (control) groups.


RESULTS
Subjects practiced an explicitly known sequence of finger movements, and were assigned to PP, real-time MI, or fast MI, in which they intentionally imagined the sequence at a faster pace. A NoSleep group subjected to real-time MI, but without any intervening sleep, was also tested. Performance was evaluated before practice, as well as prior to, and after a night of sleep or a similar time interval during the daytime. Compared with the NoSleep group, the results revealed offline gains in performance after sleep in the PP, real-time MI, and fast MI groups. There was no correlation between a measure of underestimation of the time to imagine the motor sequence and the actual speed gains after sleep, neither between the ease/difficulty to form mental images and performance gains.


CONCLUSIONS
These results provide evidence that sleep contributes to the consolidation of motor sequence learning acquired through MI and further suggests that offline delayed gains are not related to the MI content per se. They extend our previous findings and strongly confirm that performance enhancement following MI is sleep dependent.
Debarnot
Ursula
U
Centre de Recherche et d'Innovation sur le sport, Laboratoire de la Performance Motrice, Mentale et du Materiel, Université Claude Bernard Lyon I, Université de Lyon, Villeurbanne, France.
Creveaux
Thomas
T
Collet
Christian
C
Doyon
Julien
J
Guillot
Aymeric
A
D000328:Adult; D005260:Female; D006801:Humans; D007092:Imagination / Q000502:physiology*; D007858:Learning / Q000502:physiology; D008297:Male; D008568:Memory / Q000502:physiology*; D008606:Mental Processes / Q000502:physiology; D009048:Motor Skills / Q000502:physiology*; D011214:Practice, Psychological; D011597:Psychomotor Performance / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult