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- Title
Visuotopic Cortical Connectivity Underlying Attention Revealed with White-Matter Tractography.
- Authors
Greenberg, Adam S.; Verstynen, Timothy; Yu-Chin Chiu; Yantis, Steven; Schneider, Walter; Behrmann, Marlene
- Abstract
Visual attention selects behaviorally relevant information for detailed processing by resolving competition for representation among stimuli in retinotopically organized visual cortex. The signals that control this attentional biasing are thought to arise in a frontoparietal network of several brain regions, including posterior parietal cortex. Recent studies have revealed a topographic organization in the intraparietal sulcus (IPS) that mirrors the retinotopic organization in visual cortex, suggesting that connectivity between these regions might provide the mechanism by which attention acts on early cortical representations. Using white-matter imaging and functional MRI, we examined the connectivity between two topographic regions of IPS and six retinotopically defined areas in visual cortex.Weobserved a strong positive correlation between attention modulations in visual cortex and connectivity of posterior IPS, suggesting that these white-matter connections mediate the attention signals that resolve competition among stimuli for representation in visual cortex. Furthermore,wefound that connectivity between IPS andV1consistently respects visuotopic boundaries, whereas connections toV2and V3/VP disperse by 60%. This pattern is consistent with changes in receptive field size across regions and suggests that a primary role of posterior IPS is to code spatially specific visual information. In summary,wehave identified white-matter pathways that are ideally suited to carry attentional biasing signals in visuotopic coordinates from parietal control regions to sensory regions in humans. These results provide critical evidence for the biased competition theory of attention and specify neurobiological constraints on the functional brain organization of visual attention.
- Subjects
ATTENTION; NEURAL circuitry; VISUAL evoked response; CELLULAR signal transduction; MAGNETIC resonance imaging of the brain; VISUAL cortex; BRAIN function localization
- Publication
Journal of Neuroscience, 2012, Vol 32, Issue 8, p2773
- ISSN
0270-6474
- Publication type
Article
- DOI
10.1523/JNEUROSCI.5419-11.2012