Non-determinism in the uptake of gestural information

It is well established that gestures and speech form an integrated system of communication; gestures that match the meaning of the speech they accompany favor the listener's discourse comprehension, whereas mismatching gestures whose meaning conveys information contradicting that conveyed by speech, impair comprehension. A less investigated issue is whether or not the uptake of gestural information is a deterministic process. In line with recent studies in the literature, we purport that the process may be modulated by certain factors. In particular, we investigate the role of unrelated gestures whose meaning, which is irrelevant to the speech they accompany, could be neglected. The results of four experiments led us to conclude that unrelated gestures are not processed, and that the uptake of gestural information is a non-deterministic process.