title: White matter and task-switching in young adults: A Diffusion Tensor Imaging study.
abstract: The capacity to flexibly switch between different task rules has been previously associated with distributed fronto-parietal networks, predominantly in the left hemisphere for phasic switching sub-processes, and in the right hemisphere for more tonic aspects of task-switching, such as rule maintenance and management. It is thus likely that the white matter (WM) connectivity between these regions is critical in sustaining the flexibility required by task-switching. This study examined the relationship between WM microstructure in young adults and task-switching performance in different paradigms: classical shape-color, spatial and grammatical tasks. The main results showed an association between WM integrity in anterior portions of the corpus callosum (genu and body) and a sustained measure of task-switching performance. In particular, a higher fractional anisotropy and a lower radial diffusivity in these WM regions were associated with smaller mixing costs both in the spatial task-switching paradigm and in the shape-color one, as confirmed by a conjunction analysis. No association was found with behavioral measures obtained in the grammatical task-switching paradigm. The switch costs, a measure of phasic switching processes, were not correlated with WM microstructure in any task. This study shows that a more efficient inter-hemispheric connectivity within the frontal lobes favors sustained task-switching processes, especially with task contexts embedding non-verbal components.
authors.affiliation: Department of Neuroscience, University of Padova, Italy; Centro di Neuroscienze Cognitive, University of Padova, Italy. Electronic address: antonino.vallesi@unipd.it.
authors.forename: Antonino
authors.initials: A
authors.lastname: Vallesi
authors.affiliation: Department of Neuroscience, University of Padova, Italy; Department of Information Engineering, University of Padova, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Mastrorilli
authors.affiliation: Neuroradiology Unit, Azienda Ospedaliera di Padova, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Causin
authors.affiliation: Department of Neuroscience, University of Padova, Italy; Centro di Neuroscienze Cognitive, University of Padova, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: D'Avella
authors.affiliation: Department of Information Engineering, University of Padova, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Bertoldo
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging*; D056324:Diffusion Tensor Imaging; D056344:Executive Function; D005260:Female; D006801:Humans; D008037:Linguistics; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D011930:Reaction Time; D012044:Regression Analysis; D013028:Space Perception; D014796:Visual Perception; D066127:White Matter / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: FSL; corpus callosum; executive functions; fractional anisotropy; radial diffusivity; task-switching