The Problem of Over Completeness

  • We have seen that the eye muscles and brainstem neural circuits have a capacity to rotate the eye in 3 dimensions.
  • To point the fovea at an object is a 2 dimensional problem, it can be done with only vertical and horizontal rotations.
  • Thus the brain has a choice of final positions (A or B or C).
  • Donders found that the brain always made the same choice (i.e. B, not A or C).
  • This property is called Donders' law.

Copyright © 1996 Tutis Vilis and Douglas Tweed
University of Western Ontario
London Ontario Canada
Updated October 28, 2005

Comments welcome. Email to tutis.vilis@schulich.uwo.ca