About motion perception, please help

[smartnose]

Hello everyone:

My major is not neuroscience, but I came across a motion perception
problem recently: The background image is static, but on the surface
of this background, there are many bubbles drifting in a transparent
flow. No doubt that we, humans, can perceive this flow by the
distortion of the background image from these little bubbles, but this
kind of motion is not caused by the apparent motion of any visible
objects. I wonder if in neuroscience, there's a specific jargon that
refers to this kind of abstract motion 'caused by a local functional
that depends on time.

I read about "Motion perception: the long and short of it" and another
chapter of a book on vision. In these literature, the motion
perception seems to be classified into first and second order motion
which are based on the intensity and local statistics, but it looks
that the classification in these papers is still not what I'm looking
for.

Please help .

Thanks

Wei