title: Action observation training modifies brain gray matter structure in healthy adult individuals.
abstract: Action observation training (AOT) is thought to facilitate motor system function. We applied voxelwise methods to assess the regional modifications of brain gray matter (GM) volumes and white matter (WM) architecture in healthy subjects following AOT and their correlations with improvements at motor and cognitive functional scales. Forty-two righ-handed healthy subjects were randomized into an experimental (AOT-G, n = 20) and a control (C-G, n = 22) group. The training lasted 2 weeks and consisted of 10 sessions of 45 min each during which subjects watched videos of daily-life actions (AOT-G) or landscapes (C-G), alternated by the execution with the right hand of actions presented in the AOT-G videos. At baseline and follow up, motor and cognitive functional measures as well as brain structural MRI scans were obtained. Tensor-based morphometry and tract-based spatial statistics were used to map longitudinal modifications of GM and WM structures and their correlation with functional scales. After training, both groups improved at cognitive tests, whereas the AOT-G also improved hand motor performance. Following training, no modifications of WM diffusion tensor MRI indexes were detected. After training, compared to C-G, AOT-G had increased volume of the left superior frontal gyrus and decreased volume of the right lingual gyrus. Compared to AOT-G, C-G showed increased volume of the right middle frontal gyrus and left inferior temporal gyrus. In AOT-G, GM volume changes correlated with improvements at cognitive tests. Ten-day AOT in healthy individuals modifies GM structure, promoting structural brain plasticity and functional competence.
authors.affiliation: Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.|Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Rocca
authors.affiliation: Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.|Laboratory of Movement Analysis, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Fumagalli
authors.affiliation: Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Pagani
authors.affiliation: Laboratory of Movement Analysis, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Gatti
authors.affiliation: Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.
authors.forename: Gianna C
authors.initials: GC
authors.lastname: Riccitelli
authors.affiliation: Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.|Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Preziosa
authors.affiliation: Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Comi
authors.affiliation: Department of Neuroradiology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Falini
authors.affiliation: Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy. filippi.massimo@hsr.it.|Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy. filippi.massimo@hsr.it.
authors.forename: Massimo
authors.identifier: http://orcid.org/0000-0002-5485-0479
authors.initials: M
authors.lastname: Filippi
mesh_terms: D000328:Adult; D001921:Brain / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000502:physiology; D005260:Female; D066128:Gray Matter / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000502:physiology; D006225:Hand / Q000502:physiology; D006801:Humans; D007858:Learning / Q000502:physiology; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D009039:Motion Perception / Q000502:physiology; D009048:Motor Skills / Q000502:physiology; D009434:Neural Pathways / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology; D009473:Neuronal Plasticity; D009929:Organ Size
keywords: Action observation training; Gray matter; Healthy subjects; Magnetic resonance imaging; Structural plasticity; White matter