Structural organization of the corpus callosum predicts attentional shifts after continuous theta burst stimulation

Repetitive transcranial magnetic stimulation (rTMS) applied over the right posterior parietal cortex (PPC) in healthy participants has been shown to trigger a significant rightward shift in the spatial allocation of visual attention, temporarily mimicking spatial deficits observed in neglect. In con...

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Main Authors: Chechlacz, Magdalena, Humphreys, Glyn W., Sotiropoulos, Stamatios N., Kennard, Christopher, Cazzoli, Dario
Format: Article
Published: Society for Neuroscience 2015
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Online Access:https://eprints.nottingham.ac.uk/52865/
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author Chechlacz, Magdalena
Humphreys, Glyn W.
Sotiropoulos, Stamatios N.
Kennard, Christopher
Cazzoli, Dario
author_facet Chechlacz, Magdalena
Humphreys, Glyn W.
Sotiropoulos, Stamatios N.
Kennard, Christopher
Cazzoli, Dario
author_sort Chechlacz, Magdalena
building Nottingham Research Data Repository
collection Online Access
description Repetitive transcranial magnetic stimulation (rTMS) applied over the right posterior parietal cortex (PPC) in healthy participants has been shown to trigger a significant rightward shift in the spatial allocation of visual attention, temporarily mimicking spatial deficits observed in neglect. In contrast, rTMS applied over the left PPC triggers a weaker or null attentional shift. However, large interindividual differences in responses to rTMS have been reported. Studies measuring changes in brain activation suggest that the effects of rTMS may depend on both interhemispheric and intrahemispheric interactions between cortical loci controlling visual attention. Here, we investigated whether variability in the structural organization of human white matter pathways subserving visual attention, as assessed by diffusion magnetic resonance imaging and tractography, could explain interindividual differences in the effects of rTMS. Most participants showed a rightward shift in the allocation of spatial attention after rTMS over the right intraparietal sulcus (IPS), but the size of this effect varied largely across participants. Conversely, rTMS over the left IPS resulted in strikingly opposed individual responses, with some participants responding with rightward and some with leftward attentional shifts. We demonstrate that microstructural and macrostructural variability within the corpus callosum, consistent with differential effects on cross-hemispheric interactions, predicts both the extent and the direction of the response to rTMS. Together, our findings suggest that the corpus callosum may have a dual inhibitory and excitatory function in maintaining the interhemispheric dynamics that underlie the allocation of spatial attention.
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spelling nottingham-528652020-05-04T17:22:28Z https://eprints.nottingham.ac.uk/52865/ Structural organization of the corpus callosum predicts attentional shifts after continuous theta burst stimulation Chechlacz, Magdalena Humphreys, Glyn W. Sotiropoulos, Stamatios N. Kennard, Christopher Cazzoli, Dario Repetitive transcranial magnetic stimulation (rTMS) applied over the right posterior parietal cortex (PPC) in healthy participants has been shown to trigger a significant rightward shift in the spatial allocation of visual attention, temporarily mimicking spatial deficits observed in neglect. In contrast, rTMS applied over the left PPC triggers a weaker or null attentional shift. However, large interindividual differences in responses to rTMS have been reported. Studies measuring changes in brain activation suggest that the effects of rTMS may depend on both interhemispheric and intrahemispheric interactions between cortical loci controlling visual attention. Here, we investigated whether variability in the structural organization of human white matter pathways subserving visual attention, as assessed by diffusion magnetic resonance imaging and tractography, could explain interindividual differences in the effects of rTMS. Most participants showed a rightward shift in the allocation of spatial attention after rTMS over the right intraparietal sulcus (IPS), but the size of this effect varied largely across participants. Conversely, rTMS over the left IPS resulted in strikingly opposed individual responses, with some participants responding with rightward and some with leftward attentional shifts. We demonstrate that microstructural and macrostructural variability within the corpus callosum, consistent with differential effects on cross-hemispheric interactions, predicts both the extent and the direction of the response to rTMS. Together, our findings suggest that the corpus callosum may have a dual inhibitory and excitatory function in maintaining the interhemispheric dynamics that underlie the allocation of spatial attention. Society for Neuroscience 2015-11-18 Article PeerReviewed Chechlacz, Magdalena, Humphreys, Glyn W., Sotiropoulos, Stamatios N., Kennard, Christopher and Cazzoli, Dario (2015) Structural organization of the corpus callosum predicts attentional shifts after continuous theta burst stimulation. Journal of Neuroscience, 35 (46). pp. 15353-15368. ISSN 1529-2401 corpus callosum; diffusion tractography; individual differences; neglect; spatial attention; TMS http://www.jneurosci.org/content/35/46/15353 doi:10.1523/JNEUROSCI.2610-15.2015 doi:10.1523/JNEUROSCI.2610-15.2015
spellingShingle corpus callosum; diffusion tractography; individual differences; neglect; spatial attention; TMS
Chechlacz, Magdalena
Humphreys, Glyn W.
Sotiropoulos, Stamatios N.
Kennard, Christopher
Cazzoli, Dario
Structural organization of the corpus callosum predicts attentional shifts after continuous theta burst stimulation
title Structural organization of the corpus callosum predicts attentional shifts after continuous theta burst stimulation
title_full Structural organization of the corpus callosum predicts attentional shifts after continuous theta burst stimulation
title_fullStr Structural organization of the corpus callosum predicts attentional shifts after continuous theta burst stimulation
title_full_unstemmed Structural organization of the corpus callosum predicts attentional shifts after continuous theta burst stimulation
title_short Structural organization of the corpus callosum predicts attentional shifts after continuous theta burst stimulation
title_sort structural organization of the corpus callosum predicts attentional shifts after continuous theta burst stimulation
topic corpus callosum; diffusion tractography; individual differences; neglect; spatial attention; TMS
url https://eprints.nottingham.ac.uk/52865/
https://eprints.nottingham.ac.uk/52865/
https://eprints.nottingham.ac.uk/52865/