Gaze Control Model Research Articles

Dynamic feedback to the superior colliculus in a neural network model of the gaze control system

The role of the superior colliculus (SC) has been explored in the context of the gaze control system, with the conclusion that recent data place it inside the control loop calculating gaze error. A neural network proposed for the SC achieves both spatial and temporal integration of gaze signals. When placing the SC inside a gaze control loop, linear time-space transformations can be achieved even with restricted feedback on the edges of the map. The proposed gaze control model can reproduce all of the properties of previous head-fixed models. However, for the first time, a collicular mechanism is shown to provide plausible explanations for conflicting results upon electrical stimulation of rostral versus caudal sites on the colliculus, and can generate reasonable trajectories for both eye and head platforms in the head-free condition. The key assumption is the distribution of a common motor (gaze) error to the platforms contributing to the movement.

Natural coordinates for specification of eye movements

Tweed and Vilis ( Journal of Neurophysiology, 58, 832–849, 1987) have argued that quaternion algebra provides the most appropriate description of the rotations of the eye, and have derived a three-dimensional model of gaze control based on quaternion operations. Euler angles give a simpler description of the rotations of the eye, and can also be used to formulate an alternative version of the three-dimensional gaze control model. Comparison of the two versions of the model highlights the distinction between the functional predictions of the model, and the predictions which depend only on the choice of mathematical descriptions.