A, Differential activity between HVF+ and HVF− conditions during shaping and holding epochs in all the recorded neurons (HVF+ and HVF−) with (MNs) and without (non-MNs) mirror properties. *p < 0.001. B, Correlation plot between HVF and grasping observation activity in HVF+ MNs (see Materials and Methods). The dashed line represents the function x = y. Note that, by performing the same analysis after removal of pairs of entries in which one or both of the values exceeded 2 SDs from the mean of their distribution (n = 3), the correlation remained significant (r = 0.4, p = 0.0013).