Influence of prehension movements observation on number production

Grade, Stéphane [UCL] badets, Arnaud [CNRS (France)] Pesenti, Mauro [UCL]

Recent findings show that the sensory-motor areas underlying finger movement play a critical role in numerical cognition. Given these links between embodied action perspectives and numerical concepts, we suggest that observing certain types of actions should have an effect on the selection and the production of numerical responses. Therefore, the present study assessed whether observing finger, hand or mouth movements were able to influence a random number generation task, and how the influence effect moderated for the different kinds of movements. The experimental task required that participants randomly produced a number between 1 and 10 after they first perceived an action stimulus of either closing or an opening finger, hand and mouth grip movement, or they perceived stimuli color changes (a control comparison condition). The results revealed that random number production was influenced by the prior presentation of the finger movements, whereby observing a closing finger grip movement led participants to produce more small than large numbers than in the baseline condition, while observing an opening finger grip movement led participants to produce more large than small numbers. For one of the hand movement (i.e., rope grip) conditions, the number production was not influenced. For the other hand movement (i.e., tennis ball grip) conditions, the closing movement induced participants to produce more small than large numbers. Finally, in the mouth movement condition, the observation of the mouth opening movement led participants to produce more large than small numbers. Taken together, these results showed that some of the characteristics of the observed finger, hand and mouth grip movements appeared to automatically prime the number generation task. The findings are discussed in terms of the functional and neural mechanisms that might explain the effect, and support the view that number semantics might be grounded on sensory-motor mechanisms.