Fig. 1.

Mirror neuron showing adaptation during observation of a repeated grasp. A: firing pattern of the same representative F5 mirror neuron in 10 successive trials (vertical black dashes) aligned to the moment the object was grasped (time zero). Trial number increases from top to bottom. Red dots show the relative time of the onset of the observed action. The gray box indicates the 500 ms before the observed grasp and the yellow box indicates the 500 ms after the observed grasp. B: same data as in A but plotting the firing rate of the neuron as a function of perievent time (object grasp) and presentation order. As before the red dots show the relative onset of the observed action. Note the systematic decrease in firing rate with successive trials. C and E: examples of 2 mirror neurons during observation of different actions. Blue lines show the response when the monkey observed a precision grip to pick up a piece of food, red lines show the response of the neuron when observing a precision grip to a piece of food concealed in a bowl, purple lines show the response when observing a precision grip to no object, and green lines show the response to observing the experimenter placing his/her hand flat in front of the monkey. D and F: response of these two neurons when the monkey executed a precision grip task.