Mirror Neuron Dr. Raya Ariel

1. Mirror NeuronDr. Raya Ariel The Department of Child and Adolescent Psychiatry Schneider Children's Medical Center of Israel

2. Definition: • Mirror neurons are a class of neurons in the parietal lobe. • Discovered monkeys in 1992 and studied ever since then. • They discharge both when the animal performs an action (grasps an object) and sees another individual make a similar action (monkey or human).

3. Research Paradigm • Microscopic electrodes inserted into single neurons. • Animal hooked to machine which records it’s firing. • Discovery of the function of these neuron happened by accidental (the raisin).

4. Mirror Neuron facts • For these neurons to fire the monkey has to see an object-directed action (object alone or hand movement alone is not enough). • The mere observation of an object not acted upon does not evoke a response either. • Reward not relevant to firing. • Mirror neurons can be driven not only by action execution and observation, but also by the sound produced by the same action

5. Mirror neurons related to mouth action • More recently studied • Located in a different area • 1 class – ingestive functions (grasping food with mouth, sucking etc.) • 2 class – communication gestures • 1 & 2 related. • Evolution – in monkeys origin of communication movement in ingestive movements of mouth

6. Mechanism of action understanding • Each time monkey sees action by another individual, neurons that are activated when the same action is executed by himself are firing. • Thus the monkey has knowledge of the other’s action from his own activity.

7. Human Mirror Neurons • The mirror neuron system for actions in humans cannot be directly studied. • fMRI paradigms • Rizzolatti (in 2005) found that when people listened to sentences describing actions, the same mirror neurons fired as would have fired had they performed the actions or witnessed them being performed.

8. fMRI findings • Experiencing disgust and witnessing the same emotion expressed by someone else activate the same neural structure. • The areas that responded to observation of mouth actions also responded to reading sentences about mouth actions • Thus that in addition to execution, action observation, and the sounds of actions, these neurons may also be activated by abstract representations of actions, namely language."

9. Empaty - emotions • Mirror neuron network in man involves and activates Amygdala (emotions) • We do not accomplish understanding of other’s feelings by analogy or thinking processes. • Rather, the other’s emotion is experienced by ourselves and therefore directly understood. It is a shared body state.

10. “let’s be in touch” • The experience of being touched activates the same neural networks as observing someone else being touched

11. Language • Language theory hold that actions have a syntax similar to that of spoken or signed language. It’s “Hand grasps ball” • Language rises from the same syntactic understanding that our mirror neurons generate.

12. Evolution of language • Once you have two abilities in place; • the ability to read someone's intentions (through your own) • the ability to mime their vocalizations then you have set in motion the evolution of language. You need no longer speak of a unique language organ and the evolution of language doesn't seem quite so mysterious any more.

13. Social Skills • Anytime you watch someone else doing something (or even starting to do something), the corresponding mirror neuron fires in your brain, thereby allowing you to "read" and understand another's intentions, and thus to develop a sophisticated "theory of other minds."

14. Mirror neuron in Autism • Mirror neurons that fired in nonautistic people watching someone else make meaningless finger movements didn’t fire in autistic children. • Both autistic and nonautistic adolescents watched pictures of people with distinctive facial expressions. Both subjects could imitate the expressions and say what emotions they expressed. But while the nonautistic teens showed robust activity in mirror neurons corresponding to the emotions expressed, the autistic teens showed no such activity. • They understood the expressions cognitively but felt no empathy.

15. a decade of research has shown that people with autism tend to have difficulty imitating others, especially when those movements are complex • There is a controversial claim that the repetitious behaviors characteristic of autism may arise from an unregulated mirror system.

16. Mirror neuron - Violence • Mirror neurons may reveal a new perspective on the dynamics of violent video games. • Studies suggest that such games reinforce, at a basic neuronal level, an association of pleasure and accomplishment with inflicting harm. • The power of mirror neurons systems suggests that imitative violence may not always be a consciously mediated process. Namely, less subject to control than we would like.

17. Ramachandran • "I predict that mirror neurons will do for psychology what DNA did for biology," • "They will provide a unifying framework and help explain a host of mental abilities that have hitherto remained mysterious and inaccessible." • Mirror neurons primed the human brain for the great cultural leap forward. • Once we had the ability to imitate, and learn through imitation, transmission of culture could continue by leaps and bounds.