Attentional capture and inhibition of saccades after irrelevant and relevant cues

The priority of goal-relevant information and evolutionarily threatening information in early attention processing:Evidence from behavioral and ERP study

Previous studies have demonstrated that evolutionarily threatening information and goal-relevant information can both capture attention. However, some studies have suggested that goal-relevant information is prioritized over evolutionarily threatening information, while some studies have shown the opposite conclusion. The aim of the present study was to investigate the attention advantage by presenting evolutionarily threatening information and goal-relevant information simultaneously. Three conditions were presented in this study: evolutionarily threatening information + an irrelevant stimulus, goal-relevant information + an irrelevant stimulus, and evolutionarily threatening information + goal-relevant information. The behavioral results showed no attentional bias toward evolutionarily threatening information in the two conditions including evolutionarily threatening information; in the two conditions including goal-relevant information, participants showed attentional bias toward goal-relevant information in both. However, the ERP results showed that in the two conditions including evolutionarily threatening information, a significantly stronger N2pc response was seen for evolutionarily threatening information than for the other types of pictures, and goal-relevant information produced a significantly stronger N2pc response than that for an irrelevant stimulus. The abovementioned results indicated that in the earlier stage of attention, both evolutionarily threatening information and goal-relevant information have attention processing advantages over irrelevant stimuli; furthermore, attention was captured by evolutionarily threatening information faster than it was by goal-relevant information.

The effect of modulating top-down attention deployment on the N2pc/PCN

The N2pc (PCN) component of the event-related potential (ERP) waveform provides a useful tool for directly assessing the locus of spatial attention in visual search. It is still unclear whether the amplitude of the N2pc/PCN relates to the deployment of attentional resources. A key issue is the lack of evidence that top-down allocation of attention affects the N2pc/PCN amplitude. Previous findings could be explained if manipulating different expectancy strategies changes participants' search mode, causing them to redefine the target's features. In this study, we explored the relationship between N2pc/PCN amplitude and top-down attention allocation by manipulating the discriminative difficulty (differences in the response-defining feature) but leaving the search difficulty (target's saliency) unchanged. Using the same sets of stimuli, in a blocked condition, participants showed the expected higher amplitude of N2pc/PCN in the hardest condition, compared to easier discrimination conditions. Importantly, there was no difference in the N2pc/PCN when the exact same stimulus sets were presented in a randomly interleaved mixed set. At a behavioral level, in both conditions performance was significantly slower for the hardest condition. This finding indicates that the N2pc/PCN component is modulated by the predictability of discriminative difficulty, which reflects the modulation of top-down attentional deployment.