title: The time course of task-specific memory consolidation effects in resting state networks.
abstract: Previous studies have reported functionally localized changes in resting-state brain activity following a short period of motor learning, but their relationship with memory consolidation and their dependence on the form of learning is unclear. We investigate these questions with implicit or explicit variants of the serial reaction time task (SRTT). fMRI resting-state functional connectivity was measured in human subjects before the tasks, and 0.1, 0.5, and 6 h after learning. There was significant improvement in procedural skill in both groups, with the group learning under explicit conditions showing stronger initial acquisition, and greater improvement at the 6 h retest. Immediately following acquisition, this group showed enhanced functional connectivity in networks including frontal and cerebellar areas and in the visual cortex. Thirty minutes later, enhanced connectivity was observed between cerebellar nuclei, thalamus, and basal ganglia, whereas at 6 h there was enhanced connectivity in a sensory-motor cortical network. In contrast, immediately after acquisition under implicit conditions, there was increased connectivity in a network including precentral and sensory-motor areas, whereas after 30 min a similar cerebello-thalamo-basal ganglionic network was seen as in explicit learning. Finally, 6 h after implicit learning, we found increased connectivity in medial temporal cortex, but reduction in precentral and sensory-motor areas. Our findings are consistent with predictions that two variants of the SRTT task engage dissociable functional networks, although there are also networks in common. We also show a converging and diverging pattern of flux between prefrontal, sensory-motor, and parietal areas, and subcortical circuits across a 6 h consolidation period.
authors.affiliation: Behavioural Brain Sciences Centre, School of Psychology, University of Birmingham, Birmingham B15 2TT, United Kingdom, and Berneson-Allen Center for Noninvasive Brain Stimulation, Harvard Medical School, Boston, Massachusetts 02215.
authors.forename: Saber
authors.initials: S
authors.lastname: Sami
authors.forename: Edwin M
authors.initials: EM
authors.lastname: Robertson
authors.forename: R Chris
authors.initials: RC
authors.lastname: Miall
mesh_terms: D000293:Adolescent; D000328:Adult; D001479:Basal Ganglia / Q000166:cytology / Q000502:physiology; D001921:Brain / Q000166:cytology* / Q000502:physiology*; D001931:Brain Mapping; D002531:Cerebellum / Q000166:cytology / Q000502:physiology; D002540:Cerebral Cortex / Q000166:cytology / Q000502:physiology; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D012146:Rest / Q000502:physiology; D013788:Thalamus / Q000166:cytology / Q000502:physiology; D055815:Young Adult
keywords: ICA; consolidation; fMRI; motor learning; resting state