Emotional states modulate the recognition potential during word processing

Abstract

This study examined emotional modulation of word processing, showing that the recognition potential (RP), an ERP index of word recognition, could be modulated by different emotional states. In the experiment, participants were instructed to compete with pseudo-competitors, and via manipulation of the outcome of this competition, they were situated in neutral, highly positive, slightly positive, highly negative or slightly negative emotional states. They were subsequently asked to judge whether the referent of a word following a series of meaningless character segmentations was an animal or not. The emotional induction task and the word recognition task were alternated. Results showed that 1) compared with the neutral emotion condition, the peak latency of the RP under different emotional states was earlier and its mean amplitude was smaller, 2) there was no significant difference between RPs elicited under positive and negative emotional states in either the mean amplitude or latency, and 3) the RP was not affected by different degrees of positive emotional states. However, compared to slightly negative emotional states, the mean amplitude of the RP was smaller and its latency was shorter in highly negative emotional states over the left hemisphere but not over the right hemisphere. The results suggest that emotional states influence word processing.

Figure 1. Illustration of the procedure.

The emotional induction task and the word recognition task were alternated. In this example, the first 4 stimuli after the fixation in Task 2 are word fragments, and the fifth is a word.

Figure 2. The top panel shows ERPs elicited by word processing under five emotional states at PO7 and PO8 electrodes.

The bottom panel shows topographic maps for difference waves between neutral and each of the other four emotional states during the time window of 250–280 ms after stimulus onset. A clear recognition potential (RP) over the occipital scalp can be indentified under the neutral (NEU), highly positive (HP), slightly positive (SP), highly negative (HN) and slightly negative (SN) emotional states, which is highest in the case of the neutral emotional state.

Figure 3. The comparison between neutral (NEU) and other emotional states (EMO).

Figure 4. The comparison between positive (POS) and negative (NEG) emotional states.