Event-related potentials during an emotional stroop task

Emotional Stroop tasks have gained wide interest in scientific literature in the last two decades. Although no direct measure of attention is

employed, these studies infer the presence of preferential processing of threatening information based on reaction time (RT) impairment in a

competing task. Because event-related potential (ERP) measures are sensitive to both the extent (amplitude) and speed (latency) of cerebral

processing, they are valuable tools with which to examine more directly the claim that threatening stimuli are associated with enhanced attention.

Twenty-two students rated a pool of words to identify those that were personally disturbing. Two word types (threat and neutral) were then

compared in two tasks (color relevant, in which the color ink of words was identified, and word relevant in which words were classified as

threatening or not). No emotional Stroop effect was observed in terms of longer RTs to identify the colors of threat words. ERP results provided

valuable information about threat processing which was not observed with behavioral measures. Threat content was associated with larger P2

amplitude in the right than left hemisphere, and larger P3 amplitude, across tasks. The results indicate strong evidence for enhanced processing of

threat-related stimuli in healthy individuals. It is concluded that ERPs are a sensitive measure of processes underlying emotional Stroop

performance, which can be used to elucidate attentional biases in healthy and clinical populations.