Figure 1.

Mediated activation accounts may be proposed to explain mirror neuron (MN) responses to tool-use and action sounds if it is assumed that sensory inputs gain access to an innate MN system via (a) hardwired visual descriptions of actions executed with biological effectors, or (b) hardwired representations of abstract action goals. However, while these interpretations are logically plausible, findings that MNs show stronger responses to the sight of actions performed with tools, and to action sounds, than to the sight of grasping or ripping alone, argue against mediated activation. Instead, some MNs appear to have receptive fields tuned to sensory inputs other than the sight of gripping or tearing executed with biological effectors.