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Christian Keysers

Keysers Group

I feel you: emotional mirror neurons found in the rat

Why is it that we can get sad, when we see someone else crying? Why is it that we wince, when a friend cuts his finger? Researchers from the Netherlands Institute for Neuroscience have found that the rat brain activates the same cells when they observe the pain of others as when they experience pain themselves. In addition, without activity of these “mirror neurons”, the animals no longer share the pain of others. As many psychiatric disorders are characterized by a lack of empathy, finding the neural basis for sharing the emotions of others, and being able to modify how much an animal shares the emotions of others, is an exciting step towards understanding empathy and these disorders. The findings are published in the leading journal Current Biology.

Human neuroimaging studies have shown that when we experience pain ourselves, we activate a region of the brain called “the cingulate cortex”. When we see someone else in pain, we reactivate the same region.

On the basis of this, researchers formulated two speculations: (a) the cingulate cortex contains mirror neurons, i.e. neurons that trigger our own feeling of pain and are reactivated when we see the pain of others, and (b) that this is the reason why we wince and feel pain while seeing the pain of others. This intuitively plausible theory of empathy however remained untested because it is not possible to record the activity of individual brain cells in humans. Moreover, it is not possible to modulate brain activity in the human cingulate cortex to determine whether this brain region is responsible for empathy.

Rat shares emotions of others

For the first time, researchers at the Netherlands Institute for Neuroscience were able to test the theory of empathy in rats. They had rats look at other rats receiving an unpleasant stimulus (mild shock), and measured what happened with the brain and behavior of the observing rat. When rats are scared, their natural reaction is to freeze to avoid being detected by predators. The researchers found that the rat also froze when it observed another rat exposed to an unpleasant situation.

This finding suggests that the observing rat shared the emotion of the other rat. Corresponding recordings of the cingulate cortex, the very region thought to underpin empathy in humans, showed that the observing rats activated the very neurons in the cingulate cortex that also became active when the rat experienced pain himself in a separate experiment. Subsequently, the researchers suppressed the activity of cells in the cingulate cortex through the injection of a drug. They found that observing rats no longer froze without activity in this brain region.

Same region in rats and humans

This study shows that the brain makes us share the pain of others by activating the same cells that trigger our own pain. So far, this had never been shown for emotions – so called mirror neurons had only been found in the motor system. In addition, this form of pain empathy can be suppressed by modifying activity in the cingulate cortex.

“What is most amazing”, says Prof. Christian Keysers, the lead author of the study, “is that this all happens in exactly the same brain region in rats as in humans. We had already found in humans, that brain activity of the cingulate cortex increases when we observe the pain of others, unless we are talking about psychopathic criminals, who show a remarkable reduction of this activity.” The study thus sheds some light one these mysterious psychopathological disorders. “It also shows us that empathy, the ability to feel with the emotions of others, is deeply rooted in our evolution. We share the fundamental mechanisms of empathy with animals like rats. Rats had so far not always enjoyed the highest moral reputation. So next time, you are tempted to call someone “a rat”, it might be taken as a compliment…”

Listen to a podcast featuring Christian Keysers and Valeria Gazzola about this discovery.

 

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Christian Keysers

Keysers Group

While we watch a movie, we share the experiences of the actors we observe: our heart for instance starts beating faster while we see an actor slip from the roof of a tall building. Why?

Specific brain areas are involved when we perform certain actions or have certain emotions or sensations. Interestingly, some of these areas are also recruited when we simply observe someone else performing similar actions, having similar sensations or having similar emotions. These areas called ‘shared circuits’ transform what we see into what we would have done or felt in the same situation. With such brain areas, understanding other people is not an effort of explicit thought but becomes an intuitive sharing of their emotions, sensations and actions.

Christian Keysers‘ lab focuses on providing increasingly detailed insights into how exactly the brain achieves this remarkable feat of empathy. For this aim, the lab combines powerful methods to non-invasively image brain activity in humans, with an unprecedented ability to record and influence brain activity at neural levels in rodents. You can get an impression for the labs spirit in these short movies:

 

In addition, the lab explores why some people seem to show very reduced empathy, for instance in patient groups that suffer from impairments in social cognition, including autism and psychopathy. You can get an impression for that work from the following episode with Morgan Freeman:

Cover The Empathic Brain

 

Read more about our research in Christian Keysers’s book The Empathic Brain.

Available at Amazon US, EU, UK in English, or as translations into Dutch (Het empathische brein), German (Unser Empathisches Gehirn), Turkish or Japanese.

 

Or what Christian Keysers present the lab at the Marie Curie Action’s 20th Anniversary in Brussels

 

Social Brain Lab

Befitting our interest in social cognition, my lab and that of Valeria Gazzola create a joint, strongly collaborative cluster of expertise on the neural basis of social cognition that we call the Social Brain Lab.

Student projects

If you are interested in applying for an internship in the Social Brain Lab please follow the instructions in this document. This also applies to literature thesis projects.

Funding

ERC European Commission FP7

NWOMarieCurie

The Keysers lab studies fundamental issues in social neuroscience. To do so, we are entirely dependent on public funding. We are enormously thankful to the Dutch Science Foundation (NWO) and the European Commission for being dedicated patrons of such frontier science. Without the Talent Scheme of NWO that has supported our work through VENI, VIDI and VICI grants, and without the European Commission that has supported us through the ERC and several Marie Skłodowska-Curie actions, we would have been unable to tackle the mysteries of our social nature. In addition, the Dutch Government has helped us deeply through the  National Initiative for Brain and Cognition.

FACILITIES

The social brain lab is equipped to integrate research in humans and rodents. For this purpose it has the following equipment.

HUMAN RESEARCH:

Human Equipment at SBL
Human Equipment at SBL
  • 3T philips scanner at the Spinoza Center (10m away, click here for details)
  • 7T philips scanner at the Spinoza Center (10m away, click here for details)
  • 130Ch ActiChamp EEG system (that can be split in two 64Ch systems for hyperscanning)
  • Magstim Rapid TMS system with neuronavigation
  • 8Ch Soterix tDCS system

RODENT RESEARCH

  • housing facilities for mice and rats
  • 64Ch Neuralynx Electrophysiology system for freely moving rodents with silicon probes or tetrodes
  • Neurolabware two-photon laser scanning microscope with Phenosys VR system
  • DM2 fascilities for viral transfections
  • Ethovision system for behavioral analysis

DATA ANALYSIS

  • 40 Core, 2TB RAM shared ram supercomputer

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