The (in)congruence effect of co-speech gestures on language processing

The aim of this paper is to explore the phenomenon of co–speech gestures in language processing. As gestures have often been analysed predominantly within the paradigm of the rhetorical tradition, this paper will try to portray their psycholinguistic dimension, which has become increasingly important within the domain of linguistic research. Through use of experimental psycholinguistic methodology and the priming paradigm, I have compared the speed and accuracy of processing of linguistic utterances occurring only in the audio–visual modality accompanied by congruent and incongruent co–speech gestures. The results of the experiment confirmed the hypothesis that incongruence of co–speech gestures has an inhibitory effect on speed and accuracy of processing of the multimodal linguistic message. The participants’ reaction times were slower and accuracy rates lower in conditions in which the semantic congruence between the verbal and the gestural modality was nullified, and the same effect was noticed in both the native language and the first foreign language. This result speaks in favour of the claim that the verbal and gestural representational systems are interconnected and constitute a holistic picture of the mental process.