title: Practice structure improves unconscious transitional memories by increasing synchrony in a premotor network.
abstract: Sequence learning relies on formation of unconscious transitional and conscious ordinal memories. The influence of practice type on formation of these memories that compose skill and systems level neural substrates is not known. Here, we studied learning of transitional and ordinal memories in participants trained on motor sequences while scanned using fMRI. Practice structure was varied or grouped (mixing or grouping sequences during training, respectively). Memory was assessed 30 min and 1 week later. Varied practice improved transitional memory and enhanced coupling of the dorsal premotor cortex with thalamus, cerebellum, and lingual and cingulate regions and greater transitional memory correlated with this coupling. Thus, varied practice improves unconscious transitional memories in proportion to coupling within a cortico-subcortical network linked to premotor cortex. This result indicates that practice structure influences unconscious transitional memory formation and identifies underlying systems level mechanisms.
authors.affiliation: National Institutes of Health, Bethesda, MD.
authors.forename: Sunbin
authors.initials: S
authors.lastname: Song
authors.affiliation: National Institutes of Health, Bethesda, MD.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Gotts
authors.affiliation: National Institutes of Health, Bethesda, MD.
authors.forename: Eran
authors.initials: E
authors.lastname: Dayan
authors.affiliation: National Institutes of Health, Bethesda, MD.
authors.forename: Leonardo G
authors.initials: LG
authors.lastname: Cohen
mesh_terms: D000328:Adult; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology*; D009048:Motor Skills / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D009483:Neuropsychological Tests; D013997:Time Factors; D014473:Unconscious, Psychology; D055815:Young Adult