Cortical mechanisms of human imitation

How does imitation occur? How can the motor plans necessary for imitating a n action derive from the observation of that: action? Imitation may be base d on a mechanism directly matching the observed action onto an internal mot or representation of that action ("direct matching hypothesis"). To test th is hypothesis, normal human participants were asked to observe and imitate a finger movement and to perform the same movement after spatial or symboli c cues. Brain activity was measured with functional magnetic resonance imag ing. If the direct matching hypothesis is correct, there should be areas th at become active during finger movement; regardless of how it is evoked, an d their activation should increase when the same movement is elicited by th e observation of an identical movement made by another individual. Two area s with these properties were found in the left; inferior frontal cortex (op ercular region) and the rostral-most region of the right superior parietal lobule.