Consolidation and disruption of motor memory generalize across stimulus conditions in the vestibulo-ocular reflex

The vestibulo-ocular reflex (VOR) exhibits motor learning that initially depends on synaptic plasticity in the cerebellar cortex. Learned decreases in VOR gain can be disrupted by rotation in darkness immediately following learning, but consolidate rapidly if the disruption stimulus is delayed. Disruption may simply reverse the synaptic changes that have recently occurred, or it may reflect new learning at other sites. The alternative to disruption, rapid consolidation, also may take place by altering the existing memory trace or may require changes at other locations. To test these possibilities, we induced decreases in the gain of the VOR in cats that wore miniaturizing goggles. Using a range of frequencies of rotation, we investigated the patterns of generalization for disruption and for rapid consolidation of the learned changes in gain. Learning was most effective at the particular frequencies that were used during training. However, disruption and rapid consolidation were not more effective at the rotation frequencies that were used during training. Instead, after consolidation, the memory retained the frequency tuning that had been established during the learning process. We conclude that disruption and rapid consolidation may not require new learning.