Visualization of how the primary visual cortex encodes both orientation and retinotopic motion of a visual object simultaneously. As a visual stimulus the scientists used a horizontal grating moving downwards on a monitor screen (sketched at most right). From left to right: The brain's vascular surface and a 20 millisecond camera snapshot of brain activity. Dark regions represent domains in which nerve cells are active which encode the horizontal grating orientation (see pattern of red outlines). At the same time, overlaid on this patchy map, a traveling activity wave was observed moving downwards across the brain (red represents peak activity, blue depicts low amplitude). The wave thus represented the actual movement of the grating stripes independently from the orientation encoding pattern.