Individual differences in white-matter microstructure reflect variation in functional connectivity during choice.
The relation between brain structure and function is of fundamental importance in neuroscience. Comparisons between behavioral and brain-imaging measures suggest that variation in brain structure correlates with the presence of specific skills. Behavioral measures, however, reflect the integrated function of multiple brain regions. Rather than behavior, a physiological index of function could be a more sensitive and informative measure with which to compare structural measures. Here, we test for a relationship between a physiological measure of functional connectivity between two brain areas during a simple decision-making task and a measure of structural connectivity. Paired-pulse transcranial magnetic stimulation indexed functional connectivity between two regions important for action choices: the premotor and motor cortex. Fractional anisotropy (FA), a marker of microstructural integrity, indexed structural connectivity. Individual differences in functional connectivity during action selection show highly specific correlations with FA in localized regions of white-matter interconnecting regions, including the premotor and motor cortex. Probabilistic tractography, a technique for identifying fiber pathways from diffusion-weighted imaging (DWI), was used to reconstruct the anatomical networks linking the component brain regions involved in making decisions. These findings demonstrate a relationship between individual differences in functional and structural connectivity within human brain networks central to action choice.
Boorman
Erie Dell
ED
Centre for Functional MRI of the Brain, University of Oxford, Oxford OX3 9DU, United Kingdom. erie.boorman@psy.ox.ac.uk
O'Shea
Jacinta
J
Sebastian
Catherine
C
Rushworth
Matthew F S
MF
Johansen-Berg
Heidi
H
D000328:Adult; D001931:Brain Mapping; D002755:Choice Behavior / Q000502:physiology*; D005260:Female; D006801:Humans; D007206:Individuality; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000033:anatomy & histology* / Q000502:physiology*; D009434:Neural Pathways; D050781:Transcranial Magnetic Stimulation