Effects of positive pictograms and words: An emotional word superiority effect?

• Compared emotional effects of pictograms and words in an ERP study.
• Positive words and pictograms reveal comparable effects between 240 and 300 ms.
• Later sustained emotional effects even enhanced for word stimuli.
• No picture superiority effect observed for complexity-reduced pictorial stimuli.
• Instead a word superiority is visible in a valence judgment paradigm.

Studies comparing verbal and pictorial stimuli with emotional content often revealed a picture advantage in terms of larger or more pronounced emotional valence effects evoked by pictorial stimuli. This picture advantage usually is accounted for by their heightened biological relevance compared to symbolic word stimuli. However, physical differences in terms of number of features and discriminability between lexical and pictorial stimuli might also account for this pattern.The present study used event-related potentials (ERPs) to examine the hypothesis that the picture advantage is associated with the pictures' heightened complexity compared to words. In a valence judgment task participants assessed the emotional impact of positive and neutral words and pictograms. It was expected that the differences in the emotion effects for these two types of stimulus modalities were diminished, as a result of the reduced complexity of the pictograms.The results show that both types of stimuli elicited significant and comparable positive-going emotional valence effects around 240–300 ms post-stimulus. However, around 340 ms after stimulus onset the valence effects evoked by pictograms were restricted to posterior regions and smaller in magnitude whereas those evoked by words were characterized by a larger and more widespread scalp distribution, possibly due to their heightened potential to exalt imagination. Furthermore, amplitudes in the late time windows evoked by pictograms over posterior regions were significantly more positive than ERP amplitudes evoked by words, suggesting that the processing of pictograms requires cognitive capacity and effort to a much greater extent than the processing of words. In conclusion, the previously reported picture superiority in emotion elicitation was not replicated using pictograms, suggesting that it can at least partially be explained by the pictures' heightened complexity and spatial distinctiveness.