Friendly drug-dealers and terrifying puppies: affective primacy can attenuate the N400 effect in emotional discourse contexts

Abstract

Words that are semantically congruous with their preceding discourse context are easier to process than words that are semantically incongruous with their context. This facilitation of semantic processing is reflected by an attenuation of the N400 event-related potential (ERP). We asked whether this was true of emotional words in emotional contexts where discourse congruity was conferred through emotional valence. ERPs were measured as 24 participants read two-sentence scenarios with critical words that varied by emotion (pleasant, unpleasant, or neutral) and congruity (congruous or incongruous). Semantic predictability, constraint, and plausibility were comparable across the neutral and emotional scenarios. As expected, the N400 was smaller to neutral words that were semantically congruous (vs. incongruous) with their neutral discourse context. No such N400 congruity effect was observed on emotional words following emotional discourse contexts. Rather, the amplitude of the N400 was small to all emotional words (pleasant and unpleasant), regardless of whether their emotional valence was congruous with the valence of their emotional discourse context. However, consistent with previous studies, the emotional words produced a larger late positivity than did the neutral words. These data suggest that comprehenders bypassed deep semantic processing of valence-incongruous emotional words within the N400 time window, moving rapidly on to evaluate the words' motivational significance.

Figure 1

Electrode Montage. Mid-regions are dark gray, and peripheral regions are light gray.

Figure 2

The effect of Congruity at each level of Emotion. Critical words in neutral scenarios showed a large N400 congruity effect, with congruous words eliciting a smaller negativity than incongruous words. In contrast, pleasant and unpleasant critical words did not show any N400 congruity effects. Both congruous and incongruous words elicited an equally small negativity.

Figure 3

The effect of Emotion on the late positivity. Over centro centro-parietal electrodes, both pleasant and unpleasant words elicited a larger late positivity than neutral words. This effect was more widespread for unpleasant than pleasant words.