Contrary to what occurs with negative pictures, negative words are, in general, not capable of interfering with performance in ongoing cognitive tasks in normal subjects. A probable explanation is the limited arousing power of linguistic material. Especially intense words (insults and compliments), neutral personal adjectives, and pseudowords were presented to 28 participants while they executed a lexical decision task. Insults were associated with the poorest performance in the task and compliments with the best. Amplitude of the late positive component of the event-related potentials, originating at parietal areas, was maximal in response to compliments and insults, but latencies were delayed in response to the latter. Results suggest that intense emotional words modulate ongoing cognitive processes through both bottom-up (attentional capture by insults) and top-down (facilitation of cognitive processing by arousing words) mechanisms.