Lateralized ERP components related to spatial orienting: discriminating the direction of attention from processing sensory aspects of the cue.

Two spatial cueing experiments were conducted to examine the functional significance of lateralized ERP components after cue-onset and to discriminate components related to sensory cue aspects and components related to the direction of attention. In Experiment 1, a simple detection task was presented. In Experiment 2, attentional selection was augmented. Two unimodal visual cueing tasks were presented using nonlateralized line cues and lateralized arrow cues. Lateralized cue effects and modulation after stimulus onset were stronger in Experiment 2. An early posterior component was related to the physical shape of arrows. A posterior negativity (EDAN) may be related to the encoding of direction from arrow cues. An anterior negativity (ADAN) and a posterior positivity (LDAP) were related to the direction of attention. The ADAN was delayed when it was more difficult to derive cue meaning. Finally, the data suggested an overlap of the LDAP and the EDAN.