Trait differences in affective and attentional responding to threat revealed by emotional stroop interference and startle reflex modulation

Abstract

This study utilized startle reflex and reaction time (RT) measures to examine the hypothesis that anxious individuals exhibit an attentional bias for threatening information. High and low trait-anxious (HTA; LTA) participants performed an emotional Stroop task in which pleasant, neutral, and threat words were presented under conditions of anticipation, or no anticipation, of electric shock. Acoustic startle probes were presented during the interval between word presentation and production of the color-naming response. HTA participants showed longer color-naming RT for threat words than pleasant words under both shock anticipation and safe conditions of the procedure. Under safe conditions, startle patterns paralleled these effects with HTA participants exhibiting smaller blink responses—indicating greater allocation of processing resources—for threat words than pleasant words. Under shock anticipation conditions, HTA individuals showed an opposite response pattern: startle blinks were potentiated for threat words relative to pleasant, indicating that the emotional impact of the threat words was enhanced by the aversive mood state. Despite evidence that the startle response effects were limited by habituation to the first half (180 trials) of the procedure, these findings support the hypothesis that HTA individuals possess an attentional bias for threatening information and exhibit greater defensive emotional reactivity to threat cues during states of heightened negative affectivity than low anxious individuals.