EVIDENCE FOR A COOPERATIVE LEARNING MECHANISM IN THE VESTIBULO-OCULARREFLEX

THE vestibule-ocular reflex (VOR) stabilizes vision by producing eye r otations that counterbalance head rotations. It receives input from a pair of vestibular receptors, and becomes unbalanced when input from o ne side is removed, producing spontaneous eye rotation in the absence of head rotation (SVOR). SVOR can be eliminated by the process of vest ibular compensation. In mammals, SVOR elimination occurs over a period of days, and follows an exponential time course. We show that SVOR el imination in goldfish occurs in a matter of minutes, and its time cour se is not exponential but is characterized by a sigmoid function sugge sting a cooperative mechanism. This time course is reproduced in a sto chastic neural network model that has nonspecific reinforcement relate d to the level of VOR imbalance.