  Huang (arXiv:1612.03270) argues that the perceptual learning induced by our
decoded neurofeedback method (DecNef) can be explained by Hebbian synaptic
plasticity of connections between V1/V2 and V3/V4 rather than that within
V1/V2, and that reinforcement learning at a cellular level should not be
possible, and thus challenges our conclusions. In this reply, first, we show
that Huang's model is not compatible with our data which strongly suggest
plasticity within V1/V2. Second, the results of our new analysis show that
spontaneous activity is not random but largely accounted for by low-dimensional
components. These and other results indicate that learning to induce a
stimulus-associated template voxel pattern in V1/V2 within as few as 100 trials
is likely to be accomplished by hyper-resolution and sub-voxel level control by
DecNef.
