title: Functional Evidence for Memory Stabilization in Sensorimotor Adaptation: A 24-h Resting-State fMRI Study.
abstract: Adaptation learning is crucial to maintain precise motor control in face of environmental perturbations. Although much progress has been made in understanding the psychophysics and neurophysiology of sensorimotor adaptation (SA), the time course of memory consolidation remains elusive. The lack of a reproducible gradient of memory resistance using protocols of retrograde interference has even led to the proposal that memories produced through SA do not consolidate. Here, we pursued an alternative approach using resting-state fMRI to track changes in functional connectivity (FC) induced by learning. Given that consolidation leads to long-term memory, we hypothesized that a change in FC that predicted long-term memory but not short-term memory would provide indirect evidence for memory stabilization. Six scans were acquired before, 15 min, 1, 3, 5.5, and 24 h after training on a center-out task under veridical or distorted visual feedback. The experimental group showed an increment in FC of a network including motor, premotor, posterior parietal cortex, cerebellum, and putamen that peaked at 5.5 h. Crucially, the strengthening of this network correlated positively with long-term retention but negatively with short-term retention. Our work provides evidence, suggesting that adaptation memories stabilize within a 6-h window, and points to different mechanisms subserving short- and long-term memory.
authors.affiliation: IFIBIO Houssay, Systems Neuroscience Group, Department of Physiology and Biophysics, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina.
authors.forename: Valeria
authors.initials: V
authors.lastname: Della-Maggiore
authors.affiliation: IFIBIO Houssay, Systems Neuroscience Group, Department of Physiology and Biophysics, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina.
authors.forename: Jorge I
authors.initials: JI
authors.lastname: Villalta
authors.affiliation: Rotman Research Institute at Baycrest Centre, University of Toronto, Toronto, Canada.
authors.forename: Natasa
authors.initials: N
authors.lastname: Kovacevic
authors.affiliation: Rotman Research Institute at Baycrest Centre, University of Toronto, Toronto, Canada.
authors.forename: Anthony Randal
authors.initials: AR
authors.lastname: McIntosh
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D001931:Brain Mapping; D056228:Feedback, Sensory / 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 / Q000000981:diagnostic imaging / Q000502:physiology; D009483:Neuropsychological Tests; D011601:Psychophysics; D011897:Random Allocation; D012146:Rest; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: consolidation; functional connectivity; motor learning; resting-state fMRI; sensorimotor adaptation