MULTIMODALATTENTION · Multimodal imaging of spatial attention networks in the human brain

Neglect, extinction and simultanagnosia constitute a group of debilitating disorders of spatial attention frequently associated with right hemisphere damage. A fronto-parietal distributed network for attention has been described but many questions remain to be answered. One major problem is the difficulty in translating anatomical information derived from animal studies to humans. Until recently there has been no direct way of studying anatomical connections or dynamic interactions between cortical areas in man. Hence, this projects aims at defining the anatomical and dynamic details of the spatial attention networks in the living human brain using state-of-the-art methodology to image connectivity. 3 different but complimentary connectivity measures will be used. Diffusion tensor tractography (DTT) allows the study of white matter connections in the living human brain. Functional magnetic resonance imaging (fMRI) connectivity measures (e.g. dynamic causal models DCM) offer a dynamic picture of connections on a time scale of several seconds. Electroencephalography (EEG) measures extend to a shorter time scale and are sensitive to interactions between cortical areas invisible to fMRI methods. The project has three overall objectives: i) to develop a novel multimodal imaging methodology allowing unprecedented access to the in-vivo anatomical, functional and dynamic characteristics of a large scale neurocognitive network. ii) to bridge the gap between monkey and human connectional anatomy in the field of attention iii) By proposing a dynamic anatomical framework we hope to understand the clinical heterogeneity of disorders of spatial attention, helping clinicians predict recovery and plan patient-specific therapeutic strategies.