As shown in this figure (Hubel and Wiesel 1968), neurons in layer 4B of V1 are selectively tuned to different directions of visual motion. The neuron shown in this figure responds most strongly to a 2 o'clock (lower left to upper right) motion, but it also responds, although less strongly to the neighboring directions. Note that motion direction tuning is in the entire range of 360 degrees, which is different from the orientation tuning in the range of 180 degrees.
The layer 4B of V1 further projects to the middle temporal area (MT) in the extrastriate cortex where most of the neurons are selectively tuned for motion velocity of different directions and speeds. In other words, the MT area is specialized for motion information processing, and V1, especially layer 4B, can be considered as the preprocessing stage of motion processing. Motion processing will be discussed later.