Les neurones miroirs

The neurophysiological studies of the last two decades have provided evidence that the motor cortex is not simply involved in movement programming and execution, but plays a main role in coding the goal of motor acts. The presence of dedicated anatomical circuits linking single premotor areas with specific areas of the posterior parietal cortex allows motor representations to be matched with several types of sensory inputs, thus allowing several types of sensorimotor integrations. An example of this matching mechanism is represented by mirror neurons, found in both the ventral premotor and the inferior parietal cortex of the monkey, responding during both observation and execution of hand and mouth motor acts. This capacity would allow individuals to understand the meaning of motor acts done by others. More recent studies on the response of these neurons during observation of motor acts performed at different distances suggested that they could play a role also in triggering different types of behavioral reactions. Furthermore, other recent studies indicate that mirror neurons may also have an important role in decoding the motor intention of others. A bulk of studies showed the presence of a parieto-premotor mirror system also in humans. Interestingly, some human studies demonstrated that this system could be modified by motor experience. This plasticity has been exploited in motor rehabilitation, to assess whether stroke patients can improve their motor function after an observation therapy. The results are positive and it seems that this therapy can be employed successfully also in children with cerebral palsy.