INC Open Mind Seminar Series
Friday, June 17, 2011 at 3:00 pm
Université Paris Descartes, LNP conference room H335, 3rd floor, 45 rue des Saints-Pères, 75006 Paris
Tamar Flash, Department of Computer Science and Applied Mathematics, Weizmann Institute, Rehovot, Israel
Motion planning, perception and compositionality: Time arising from a mixture of geometries
Behavioral and theoretical studies have led to the identification of kinematic and temporal features characterizing a variety of movements ranging from reaching to drawing and curved trajectories. These features were quite instrumental in investigating the organizing principles underlying trajectory formation. Similar constraints play also a significant role in visual perception of abstract and biological motion stimuli and in action observation.
Tamar Flash will report on several brain mapping and psychophysical studies aiming at identifying the neural correlates of these behavioral findings. She will also present a new theory of trajectory formation, inspired by geometrical invariance. The theory proposes that movement duration, kinematics, and compositionality arise from cooperation among several geometries- Euclidian, affine and equi-affine. Different geometries possess different measures of distance.
Hence, depending on the selected geometry, movement duration is proportional to the corresponding distance parameter. Expressing these ideas mathematically, the theory led to several predictions concerning drawing and locomotion trajectories, which were confirmed by examining experimental data. Tamar Flash will also discuss several of the theory implications regarding brain representations of motion.
Finally, if time permits she will describe recent studies of compositionality and multi-joint coordination in locomotion and upper limb movements.
For more information on Tamar Flash, go to: http://www.wisdom.weizmann.ac.il/~tamar/