Event-related potentials in the emotional colour naming stroop task and the emotional counting stroop task

This study compared emotional Stroop interference in the emotional colour naming Stroop and the emotional counting Stroop by measuring reaction times and event-related potentials to positive, negative and neutral words. Twenty participants had ERPs recorded at 61 sites while performing both types of emotional Stroop tasks as well as congruent and incongruent conflict conditions. All participants rated stimulus emotionality retrospectively. A robust reaction time Stroop effect was observed in response latency for the traditional ‘‘conflict’’ conditions (congruent vs. incongruent) for the counting Stroop though not the colour naming Stroop task. There was also no evidence of emotional interference for either of the tasks; however, there was trend for positive interference in the colour naming Stroop. The P5 was identified as the event-related potential associated with emotional processing. For the P5 component, significant emotionality effects were evident in the emotional colour naming Stroop for latency (542 ms). There was a significant interaction between valence and hemisphere. The latency of the P5 in the right hemisphere was later for the positive words than negative and neutral. Comparable effects of valence were evident for the emotional counting Stroop for amplitude but not latency.