Using action understanding to understand the left inferior parietal cortex in the human brain

In an fMRI study we tried to establish whether the areas in the human brain that are involved in the understanding of actions are homologous with the inferior parietal cortex (area PFG) in macaque monkeys. Cells have been described in area PFG that discharge differentially depending upon whether the observer sees food being brought to the mouth or a small object being put in a container. In our study the observers saw videos in which the use of different objects was demonstrated in pantomime; and after viewing the videos, the subject had to pick the object that was appropriate to the pantomime. We found a cluster of activated voxels in parietal areas PFop and PFt and this cluster was greater in the left hemisphere than in the right. We suggest a mechanism that could account for this asymmetry, relate our results to handedness and suggest that they shed light on the human syndrome of apraxia. Finally, we suggest that during the evolution of the hominids, this same pantomime mechanism could have been used to ‘name’ or request objects

Perception and synthesis of biologically plausible motion: From human physiology to virtual reality

6th International Workshop on Gesture in Human-Computer Interaction and Simulation, Berder Isl, FRANCE, MAY 18-20, 2005International audienceTo model and simulate human gesture is a challenge which takes benefit from a close collaboration between scientists from several fields: psychology, physiology, biomechanics, cognitive and computer sciences, etc. As an a priori requirement, we need to better understand the so-called laws of biological motions, established all along the 20(th) century. When modelled and used to animate artificial creature, these laws makes these creatures (either virtual or robotic) move in a much more realistic, life-like, fashion