Attention can be conceived as a heterogeneous set of processes, which allow us to select and act on external or internal sources of information. In order to produce coherent behavior, attention mechanisms take into account both our goals and the occurrence of unexpected events. This set of processes enables us, among else, to sustain attention in time, on a specific location or a specific feature, to reorient it toward alerting or interesting events, and to monitor our performance. The different attentional processes rely on various brain structures, forming intricate and dynamic neural networks. In particular, the integrated functioning of fronto-parietal networks, with specific interhemispheric differences often favoring the right hemisphere, is crucial for attention processes. Their impairment as a result of brain damage can hamper the conscious perception of objects in space and is a source of significant disability for patients. Our knowledge of these systems is still too limited to enable us to offer specific interventions for the whole range of attentional impairments, but it is expanding at fast pace, raising hopes for the development of effective strategies to improve the functioning of the attentional networks in brain-damaged patients.