Mirror Neurons Background

In order to gain an understanding of how mirror neurons are utilized, I thought it would be important to give some background. Mirror neurons were first discovered in monkeys in the premotor cortex originally, However, scientists have later discovered the presence of mirror neurons in other parts of the brain: parietal cortex, and somatosensory cortex. In the recent years, many scientists have done neurophysiological and brain imaging experiments. Through the utilization of medical devices (EEG, MEG, PET, fMRI scans) scientists were able to find a magnitude of evidence that proves that humans have “properties similar to the monkey’s mirror neuron system”.

The most well-known theory regarding mirror neurons is the Hebbian theory. This theory states that “a basic mechanism for synaptic plasticity wherein an increase in synaptic efficacy arises from the presynaptic cell's repeated and persistent stimulation of the postsynaptic cell”. Similar to long-term potentiation, numerous instances of stimulation through observation allows one to utilize mirror neurons. Scientists have summed up the Hebbian theory as “Cells that fire together, wire together”. The more that cells are activated the greater the synaptic strength grows between cells in a specific area. This is applied to mirror neurons in that the more that one observes and consciously thinks about the actions they are observing, the greater stimulation the mirror neurons feel. This increase in stimulation allows for a greater understanding of others actions, allowing one to recreate it easily.

The mirror neurons were discovered by a cohort of neurophysiologists in the 1990s. This group placed electrodes in the ventral premotor cortex of the macaque monkey to study neurons specialized for the control of hand and mouth actions. They recorded electrical signals from a group of neurons in the monkey's brain while the monkey was allowed to reach for pieces of food so the researchers could measure their response to certain movements”. During the study, they noticed that some neurons in the brain were activated when one would eat were also activated when they saw a person pick up a piece of food. This was incredibly interesting because they found that monkeys vicariously experienced the actions of others. Simply, they would feel the same degree of arousal when they were watching the others eat, as when they were eating.

An experiment by Christian Keysers, in 2010, showed that mirror neurons respond to the sounds of actions. Similarly, Ferrari Pier Francesco showed that “mirror neurons respond to mouth actions and facial gestures”, in 2003.