White matter and task-switching in young adults: A Diffusion Tensor Imaging study. (4th August 2016)

• Record Type: Journal Article
• Authors: Vallesi, Antonino; Mastrorilli, Eleonora; Causin, Francesco; D'Avella, Domenico; Bertoldo, Alessandra
• Is Part Of: Neuroscience. Volume 329(2016)
• Page Start: 349
• Page End: 362
• Publication Date: 2016-08-04
• Subjects: DTI Diffusion Tensor Imaging -- EPI echo-planar image -- FA fractional anisotropy -- fMRI functional magnetic resonance imaging -- MNI Montreal Neurological Institute -- RD radial diffusivity -- ROIs Regions Of Interest -- RTs response times -- SD standard deviation -- WM white matter; task-switching -- fractional anisotropy -- radial diffusivity -- executive functions -- corpus callosum -- FSL; Neurochemistry -- Periodicals; Neurophysiology -- Periodicals; Neurology -- Periodicals; Neurochimie -- Périodiques; Neurophysiologie -- Périodiques; Neurochemistry; Neurophysiology; Electronic journals; Periodicals; Electronic journals; 612.8
• DOI: 10.1016/j.neuroscience.2016.05.026
• Languages: English
• ISSNs: 0306-4522

Abstract

Highlights: DTI and performance data on three task-switching paradigms were collected on young adults. Frontal inter-hemispheric white matter integrity favors sustained task-switching. This result was observed when switching between spatial rules or color-shape ones. No relation between behavior and white matter was observed for verbal rule switching. Task-specific features determine whether white matter mediates task-switching performance. 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.