All set, indeed! N2pc components reveal simultaneous attentional control settings for multiple target colours

摘要

To study whether top-down attentional control processes can be set simultaneously for different visual features, we employed a spatial cueing procedure to measure behavioural and electrophysiological markers of task-set contingent attentional capture during search for one or two possible colour-defined targets (One Colour and Two Colour tasks). Search arrays were preceded by spatially non-predictive colour singleton cues. Behavioural spatial cueing effects indicative of attentional capture were elicited only by target-matching but not by distractor-colour cues. However, when search displays contained one target-colour and one distractor-colour object among grey nontargets, N2pc components were triggered not only by target-colour but also by distractor-colour cues both in the One Colour and Two Colour task, demonstrating that task-set nonmatching items attracted attention. When search displays contained six items in six different colours, so that participants had to adopt a fully feature-specific task set, the N2pc to distractor-colour cues was eliminated in both tasks, indicating that nonmatching items were now successfully excluded from attentional processing. These results demonstrate that when observers adopt a feature-specific search mode, attentional task sets can be configured flexibly for multiple features within the same dimension, resulting in the rapid allocation of attention to task-set matching objects only.