Abstract
The view that attention can be likened to a limited resource or capacity is generally accepted. One observation supporting this view is the finding that distractor interference obtained when the target appears alone under the low perceptual load condition is reduced when the target is embedded among nontarget items under the high perceptual load condition (Lavie, 1995). This implies that no spare resources were left for distractor processing under the high perceptual load. Similarly, in the context of stress research, acute stress is viewed as a resource-consuming situation by similar capacity approaches. The question is whether perceptual load and acute stress drain a common attentional resource. The present study examined this question by manipulating perceptual and stress loads. Participants conducted an Eriksen-type flanker interference task. Perceptual load could be low or high (2 or 5 neutral items, respectively). Participants in the stress group received a set of Trier Social Stress Test that generated speech anxiety and threatening self-esteem. The control group received a filler task. The stress induction was successful as indicated by the increase in the scores of the State-Trait Anxiety Inventory and the levels of salivary cortisol sampled before and after the stress induction. The effect of perceptual load interacted with the stress manipulation. Participants in the control group demonstrated substantial interference with low perceptual load, whereas such interference was eliminated with high perceptual load, replicating the previous studies. Importantly, the pattern of the results was opposite for the stress group. Participants showed virtually no interference with low perceptual load whereas a substantial interference occurred with high perceptual load. These results suggest that perceptual and stress load drains the same attentional resource for nontarget processing, resulting in an improvement of selective attention.