Do embodied effects reflect the consequences rather than the causes of meaning? - "Ja!"

It has been shown that a movement in a direction incongruent with the spatial semantics of words typically requires more time than movements that are directionally congruent. Two explanations have been proposed for this effect. Either a word's meaning is understood by using an internal model to simulate a word's meaning -- and incogruent directionality needs time to be resolved. Or words simply serve to reduce hearers' uncertainty about future states of the world, facilitating actions that prepare for them. However, since previous experiments have focused on actions that are directly involved in the exploration of space, they provide evidence for both hypotheses. Experiment 1 of the present study avoids this shortcoming. We investigated the basic downwards directed articulatory gesture producing a high-frequency German word, "ja" (`yes'), in response to reading words with vertical semantics. This task is thus completely unrelated to the semantics of the words. We show that tongue movements are systematically modulated by verticality ratings collected from the same speakers. To investigate the source of the effect, we performed two additional, linguistically unrelated experiments. Experiment 2 demonstrates anti-phasic coupling between tongue body movements and vertical arm and leg movements. Experiment 3 investigates tongue body movements prior to head movements and uncovers preparatory tongue raising to head raising in contrast to head lowering. Taken together, the results indicate that the changes in "ja" associated with vertical semantics most likely emerge from anticipating a head movement in the direction of the spatial target associated with the read word in order to optimize the body position for subsequent actions. Thus, the results support the assumption that words reduce the uncertainty about future states of the world.