Environmental sound priming: Does negation modify N400 cross-modal priming effects?

Human information processing is incredibly fast and flexible. In order to survive, the human brain has to integrate information from various sources and to derive a coherent interpretation, ideally leading to adequate behavior. In experimental setups, such integration phenomena are often investigated in terms of cross-modal association effects. Interestingly, to date, most of these cross-modal association effects using linguistic stimuli have shown that single words can influence the processing of non-linguistic stimuli, and vice versa. In the present study, we were particularly interested in how far linguistic input beyond single words influences the processing of non-linguistic stimuli; in our case, environmental sounds. Participants read sentences either in an affirmative or negated version: for example: "The dog does (not) bark". Subsequently, participants listened to a sound either matching or mismatching the affirmative version of the sentence ('woof' vs. 'meow', respectively). In line with previous studies, we found a clear N400-like effect during sound perception following affirmative sentences. Interestingly, this effect was identically present following negated sentences, and the negation operator did not modulate the cross-modal association effect observed between the content words of the sentence and the sound. In summary, these results suggest that negation is not incorporated during information processing in a manner that word-sound association effects would be influenced.