Schematic depiction of sample stimuli with plots showing motion profiles of extrinsic and intrinsic motion.

<p>(a) Left: Example of truly-partnered dancers. For visualization, one dancer is colored in red dots and the other in black dots. Dot size decreases for time points further in the past. Blue and green target symbols indicate roughly the centroid of the figure. Middle: Position of the centroid of each figure over time (in pixels), illustrating graphically the profile of extrinsic motion. Right: Position of the left foot point from each figure over time (in pixels) after subtracting extrinsic motion, illustrating the profile of intrinsic motion for an example joint. (b) Same as above, but for un-partnered dancers taken from two different “snippets”. Notice there is a stronger inherent correlation (Pearson’s <i>r</i>) between the intrinsic and extrinsic movements of dancers that are truly-partnered versus un-partnered.