Goal: What underlies the perception of movement? Something walks in front of us and we see it move. This makes sense – its associated retinal image changes as it moves by us. But if it stands still and we sweep our eyes across it, there is also a change in the retinal image, yet we don’t perceive movement. Why not? And what about the case where there is in fact nothing moving but yet we see movement? Or we see the wrong thing move—why? What are the circumstances that produce these perceptions and what are the underlying physiological causes of these perceptions?

Reading: Chapter 8

1. Neurobiological Basis of Motion Perception

 
2. Real Movement Perception

 
• Movement of object across stationary retina
• Physiological evidence:  Magno ganglion cells, tectnopulvinar pathway,
• directionally sensitive cells in V1 and V5/MT
• wiring a complex cell
• direct relationship between activity of MT cells and perception of motion
• random dot kinetograms
• microstimulation studies -- activity of MT cells leads to perception of motion
• other areas involved in motion perception
• Perception of movement while tracking object (no movement on retina)
• Absence of movement perception when move eye (movement across retina)
• position constancy
• Corollary Discharge Theory
 
3. Illusions of Motion