A: Circuit model for pursuit learning. Magenta pathways show teaching signals, gray shading shows sites of plasticity, and red pathway shows recurrent inhibition of inferior olive from Purkinje cells. Abbreviations are: PC, Purkinje cell; PF, parallel fiber; GC, granule cell; MF, mossy fiber; FTN, floccular target neuron; IN, inputs to floccular target neurons, v1, v2, w1, w2, synaptic weights. Reproduced with permission from Herzfeld et al. (2020). B: Circuit model for VOR learning. Abbreviations are: P, Purkinje cell; cf, climbing fiber; mf, mossy fiber; IO, inferior olive; SBC, SV, MV, sub-regions of the vestibular nuclei; III, IV, extraocular motor nuclei; EOM, extraocular muscles; AOT, CTT, pathways in the accessory optic system; VO, vestibular sensory apparatus. Panel A is modified from Herzfeld et al. (2020) and panel B is from Figure 1 of Ito (1972). Both are reproduced with permission.