Acute stress impairs target enhancement but not disrtractor suppression in attention selection: Evidence from the N2pc and Pd

Acute stress has a profound effect on attention selection, however, it remains unclear how acute stress affects target enhancement and distractor suppression in attention selection. The current study aimed to investigated the acute stress effect on target enhancement and distractor suppression in a visual search task by using ERP. The stress response was successfully induced as indexed by the activation of HPA and the subjective affect rating. Crucially, acute stress group showed significant smaller N2pc than the control group in the high-salience distractor condition, no significant differences of Pd was observed, which indicated that actue stress disrupts the target enhancement rather than the distractor suppression in attention selection. The detrimental effects might attribute to the impairing function of prefrontal cortex. The current study provide clear evidences of the impairment of target enhancement under acute stress, and reveal the cognitive mechanism of acute stress effects on attention selection. Statement of Relevance In ever-changing environment, we have developed the selective attention to focus on what is important (target enhancement) while blocking out the rest (distractor suppression). Acute stress is ubiquitous in modern day-to-day life and previous studies have found that it profoundly impacts attention selection. However, how acute stress affects target enhancement and distractor suppression in selective attention is unknown. Here, participants experience stress or control situation and then performed a visual search task isolating target enhancement and distractor suppression. Combining behavioral and ERP results, we found that stressful participants showed smaller N2pc than non-stressful participants in the target enhancement condition when the distractor salience was high, whereas no significant difference was observed for the Pd in the distractor suppression condition. These findings reveal the detrimental effect of acute stress on selective attention attribute to the impairment of target enhancement rather than distractor suppression, and highlight the importance of distractor salience.