Perception of three-dimensional structure from motion

The ability to perceive the 3-D shape of objects solely from motion cues is referred to as structure-from-motion perception. Recent experiments indicate how this remarkable perceptual attribute is computed by the brains of primates. This computation proceeds in at least two stages, one in which motion measurements are made and another in which moving surfaces are reconstructed. The middle temporal area (MT) in the macaque monkey appears to play a pivotal role in the latter step and suggests a previously unappreciated function for this well-known cortical region, which had previously been thought to play a more rudimentary role in simply signaling the direction of motion of images.