Selective visual attention is thought to be comprised of distinct neuronal networks that serve different attentional functions. The Attention Network Test (ANT) has been introduced to allow for assessment of alerting, orienting, and response inhibition. Information on associated measures of neural processing during ANT is still scarce. We topographically analyzed top-down ANT effects on visual event-related potential morphology in 44 healthy participants. Significant reaction time effects were obtained for all attention networks. Posterior cue-locked target N1 amplitude was significantly increased during both alerting and orienting. P3 amplitude was significantly modulated at frontal and parietal leads as a function of inhibition. Our data suggests that attentional mechanisms of alerting and orienting are employed simultaneously at early stages of the visual processing stream to amplify perceptual discrimination and load onto the same ERP component. Fronto-parietal modulations of P3 amplitude seem to mirror both response inhibition and visual target detection and may be interesting markers for further studies.
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