Wisdom through reflection: the mirror neuron system and its role in learning
MetadataShow full item record
Since their discovery in monkeys some seventeen years ago, mirror neurons have been the focus of an extensive debate. These neurons are active both when a monkey observes an action and when it executes the same action. Clustered in the ventral premotor cortex and inferior parietal lobule, these areas form the so-called mirror neuron system. Multiple brain imaging studies have shown activity in human brain areas homologous to mirror neuron areas in monkeys while watching and executing actions. It is therefore likely that humans also possess a mirror neuron system. This system has many connections to other brain areas and is thought to be involved in action understanding and empathy. Another possibility, which is the main topic of this thesis, is that it is also involved in certain types of learning. Mirror neurons mainly seem to code for the goals of observed actions and through connections with the limbic system they are also able to couple emotions to certain facial expressions. Indeed in both monkeys and humans they seem to be important for understanding others actions and could play a role in learning of appropriate social interactions. In humans, mirror areas show more activity than in monkeys during observation of movements themselves, next to their goals. Humans also show the ability to imitate observed actions exactly and also imitate to a much greater extent than monkeys do. Also new actions can be imitated and become integrated into the motor repertoire. The human mirror system therefore also seems to be involved in imitation learning. Finally the discovery of audiovisual mirror neurons, which respond to both vision and sound of certain actions in monkeys, also indicates this system could be involved in coupling words to certain actions. Especially in humans it probably plays a role in language learning and comprehension of language. In contrast to the direct evidence of mirror neurons in monkeys, hardly any direct evidence exists for mirror neurons in humans. In imaging studies it is not correct to simply ascribe mirror neuron activity to those brain areas that are both activated during observation and execution of action. At this moment only one preliminary study using depth electrodes shows that humans indeed possess neurons with mirror properties. Future research should shed more light on this issue and show which neurons exactly are active in humans in conditions studied so far using brain imaging techniques. The mirror neuron system indeed seems to play an important role in several types of learning. It is probably essential for imitation learning in humans. Furthermore it reduces time and costs for learning actions and goals from others by direct and automatic linking of observed actions and corresponding motor areas. In humans this is also true for action related language. However one needs to keep in mind that this system is not responsible for any type of learning on its own. It integrates information from other brain areas and in turn it is also regulated by other brain areas. It mainly is an important link in the whole process of action and goal learning.