A simple control law generates Listing's positions in a detailed model of the extraocular muscle system.
The neural commands for maintaining static Listing's positions were identified using a detailed model of extraocular muscle based on Miller and Shamaeva (Orbit 1.5 gaze mechanics simulation 1995). The commands were approximately separable, suggesting a simple control law whereby independent horizontal and vertical commands are combined to generate tertiary positions. Tests showed that this control law (i) generated Listing' s positions to reasonable accuracy over+/-30 deg, provided pulleys were represented in the model; (ii) if driven by retinal coordinates, produced errors close to the theoretical minimum for a commutative system. The proposed commands appear consistent with electrophysiological evidence.
Porrill
J
J
Department of Psychology, University of Sheffield, S10 2TP, Sheffield, UK. j.porrill@sheffield.ac.uk
Warren
P A
PA
Dean
P
P
D001696:Biomechanical Phenomena; D006801:Humans; D008432:Mathematical Computing; D009801:Oculomotor Muscles / Q000502:physiology*