14:58 Nov 23, 2009 

Michael, I believe you making an important point which you should post in answer format. I have many friends who work with children with learning and other disabilites. Orientation is different than response, and it is physical as you are discussing it.

23:56 Nov 21, 2009 

Jack Doughty is on the mark with his explanation of "register".
The other term, "orient", is not a synonym. "Orient" means that the subject changes his physical position in response to the stimulus. For example, if the stimulus is a sound, the child would normally turn his head in the direction of the sound to see what it is. If it is a visual stimulus, he stares at it. If it is tactile, he would normally withdraw or grasp, depending on the nature of the stimulus.