An Adaptive Neural Integrator Model in the Oculomotor System Based on the Commissural Inhibitory Connections

Abstract

An adaptation mechanism is proposed for the Neural Integrator (NI) of the eye movement system. The NI model has a bilateral structure with the commissural inhibitory connections, and the adaptation mechanism is based on the function of the bilateral structure. The adaptation mechanism gives the NI model a large time constant and adjusts its resting balance. Retinal-image slip signals are used as error signals. The NI connections are assumed to be separated into two classes based on their discharge type. According to the direction of the retinal slip, they are modified reciprocally : the NI connection weights of one class are modified more while those of the other class are modified less. The connection weights in each class are directly modified by using retinal slip signals without any complex calculations. The relationship between the NI adaptation mechanism and that of the pulse and step components was analyzed, and the different adaptation rates were introduced to make the NI adaptation robust. Fast adaptation rates were given to the pulse and step components, and a slow rate was given to the NI. The ability of the proposed adaptation mechanism was tested by the simulation.