Mechanism of frequency selectivity in VOR motor learning: frequency channel or waveform learning?

The vestibule ocular reflex (VOR), in which cerebellum is intimately involved to produce compensatory eye movements during head motion to stabilize retinal image. The VOR is under adaptive control whose gain (eye velocity/head velocity) can be modified by visual-vestibular mismatch stimuli. It exhibits frequency selectivity in which largest gain change is observed at the training frequency. Currently, we demonstrate in the goldfish horizontal VOR that the gains of VOR at two different frequencies can be modified in the opposite directions simultaneously: high gain at one frequency, low gain at another. We test the mechanism of this frequency selective learning if it is due to frequency channels with modifiable gains or learning of waveform per se.