A Heteromodal Large-Scale Network for Spatial Attention

Hemispatial neglect is usually designated a “parietal syndrome.” However, neglect can also arise after lesions in the frontal lobes, cingulate gyrus, striatum, and thalamus. These areas belong to an interconnected large-scale network subserving all aspects of spatial attention. This network helps to compile a mental representation of extrapersonal events in terms of their motivational salience, and to generate “kinetic strategies” so that the attentional focus can shift from one target to another. In the human, the left hemisphere controls attention predominantly within the contralateral right hemispace, whereas the right hemisphere controls attention in both hemispaces. Because of this asymmetry, severe contralesional neglect occurs almost exclusively after right hemisphere lesions and encompasses the left side of extrapersonal space.