Which color, dark blue or purple is 'sticking out'? Does the figural assignment switch with the motion?

Background: How do we recognize an object, like a hand, whose shape changes due to articulations of its parts?

My research suggests we have predetermined rules for interpreting and predicting object deformations, such as the bias to see the motion above as convex

parts articulating at concave fulcra. See more demos here.

See this paper for more info

In addition, further reearch shows that people use these rules to extrapolate from viewed shapes to new shapes they have never seen before. This work is under review; check back soon for more info!