ABSTRACT
The analysis given in chapter 6 revealed that the retinal disparities associated with stimuli restricted to the horizontal plane are qualitatively different from those associated with three - dimensional objects. Purely horizontal disparities can always have arisen from viewing a real object, but this is no longer true when both horizontal and vertical disparities are allowed. A similar situation arises in the context of eye movements, in that analysis of the control of three - dimensional eye movements shows that the task is qualitatively different from the control of one - dimensional eye movements.
