How head and visual movements affect evaluations of food products.

Many studies suggest that specific movements or postures with shared social meaning can influence mainly verbal stimuli evaluation. On the other hand, several visuospatial biases can interact with this influence. Thus, we tested whether both head and stimuli movements can influence individual attitude towards food pictures. In two experiments, we used images of common foods with a weak positive valence in association with two kinds of movements. In Experiment 1, head movement was induced by presenting food pictures with a vertical or horizontal continuous movement on a computer screen. Conversely, Experiment 2 was conducted to test the effects of participants' own head movements with respect to the same food pictures presented in a fixed position. In neither case did head movements influence product evaluation. However, Experiment 1 revealed that the continuous movement left-right-left in the horizontal condition improved the desire to buy and eat, as well as the willingness to pay for the product shown. Two further experiments, the Experiments 3 and 4 demonstrated, respectively, that this effect disappears if the stimulus does not make the return direction, and that it does not depend on the starting or final placement of the images on the screen. These findings are discussed in the context of embodied cognition and visuospatial bias theories.