Motor network activation during human action observation and imagery: Mu rhythm EEG evidence on typical and atypical neurodevelopment

• Mu rhythm is an index of action execution, observation and imagery.
• We discuss how it might reflect the mirror neuron system activation.
• We shed light to its use as a neurophysiological marker in autism.

The mental simulation theory suggests activation of the motor network during imagery and observation of human movements, similarly to the activation during action execution and is proposed to be mediated by the mirror neuron system. This activation can be measured by several technologies such as electroencephalography, magnetoencephalography, functional magnetic resonance imaging and positron emission tomography. It is proposed that motor network activation and therefore increased cortical excitability of primary motor cortex occur due to premotor mirror neuron system inputs. This mechanism has been demonstrated as important for planning actions and seems relevant for anticipating others actions and for empathy establishing as well as for language development. In this review we focused on studies relative to electroencephalography data of motor neural network activation during movement observation and imagery in typical and atypical development.