Visuospatial attention is often investigated with features related to the head or the gaze during Human-Computer Interaction (HCI). However the focus of attention can be dissociated from overt responses such as eye movements, and impossible to detect from behavioral data. Actually, Electroencephalography (EEG) can also provide valuable information about covert aspects of spatial attention. Therefore we propose a innovative approach in view of developping a Brain-Computer Interface (BCI) to enhance human reaction speed and accuracy. This poster presents an offline evaluation of the approach based on physiological data recorded in a visuospatial attention experiment. Finally we discuss about the future interface that could enhance HCI by displaying visual information at the focus of attention.