How do we read the emotions of people, what they feel when they smile or scowl? The brain is made up of several nerve cells or neurons, which are connected to each other by synapses. Neurons in one part of the brain are linked to their counterparts in another, and these form networks which perform defined functions.

Urvakhsh M. Mehta, clinician-scientist and Assistant Professor of Psychiatry at National Institute of Mental Health and Neuroscience (Nimhans), Bangalore, has been conducting research which examines the contribution of different brain networks in social interactions, particularly two systems—mirroring and mentalizing.

Mirroring is done by the reflexive brain network or the mirror neuron system (MNS), connecting frontal, temporal and parietal lobes of the brain. These neurons are active both when we perform actions and when we see similar actions performed by others. This is how we are able to intuitively grasp the connotations of their movements, the reasons and intentions behind those actions, even when not much is said explicitly

The mentalising network, also known as the reflective brain, enables us to focus on our own thoughts, making us aware of what we are thinking.

Mehta says these networks, which help us make sense of our social worlds, can be observed in day-to-day interactions; understanding them can help us gauge the perspectives of people with whom we talk before responding to them, and negotiate dialogue, especially in situations that are uncomfortable.

When did you first hear about mirror neurons? How much was known about them at the time?

I heard about them in 2007 during a discussion with my mentor on how the brain has a role to play in psychiatric disorders. Long debates have gone on in neuroscience about which brain regions or networks play roles in a person’s behaviours, and how these behaviours become abnormal. Freud’s and Carl Jung’s and others’ theories explained this to some extent. With a boom in neuroscience research over the last 25 years, a certainty emerged: psychiatric disorders do have neurobiological basis for them, and they arise out of a complex interaction of the brain with the social and cultural system we exist in.

[Later] I bought Vilayanur Ramachandran’s book Phantoms in the Brain: Probing the Mysteries of the Human Mind, read it, and gifted a copy to another mentor in Nimhans, and continued exploring various processes behind social cognition.

How does one distinguish between social cognition and general cognition?

Social cognition is how you use your cognitive abilities in social interactions. It’s a little different than general cognitive ability, as when you perform a particular task such as remembering a shopping list or a series of tasks while preparing a dish in the kitchen. This ability is not necessarily related to interpersonal equation but to non-emotion-related, non-social-cognition-related action.

Your primary area is schizophrenia. How did mirror neurons help you understand the illness?

There is so much wrong, so much out of whack in the brain of a person with schizophrenia that it’s tough to get a handle on what’s going on. The mirror neuron system helped me understand my patients better.

The thing with schizophrenia is people remain shut-in, aloof, mostly living in their own worlds, even after the hallucinations and delusions remit. They’re prone to warp others’ intentions, misinterpret others’ thoughts, words and actions, which affect their relationship with family and friends in serious ways. This happens even after they’re medically treated. So, understanding the neural mechanisms underlying social cognition and devising ways of improving it in such patients has been one of our goals.

Social cognition is modulated by the existing socio-cultural norms and schema. So, I and my colleagues developed a set of tools called SOCRATIS (Social Cognition Rating Tools in Indian Setting), evaluated it and compared it with existing western tools. Then we sought expert opinion from psychiatrists and psychologists to establish whether it’s applicable in the Indian context. SOCRATIS is now in use across several centres in the country.

What’s the role of mirror neurons in everyday life?

The concept of mirroring is omnipresent in our daily lives. From learning languages to empathising with others, from understanding actions to imitative play, we all, including infants, use our mirroring brain in our daily lives. 

In what way do mirror neurons help in social understanding?

Social understanding occurs at multiple levels: (a) the content (for e.g., emotions and thoughts); (b) the process (for e.g., reflexive or automatic & reflective or controlled); (c) the interpersonal realm (self versus other); and (d) the complexities (inferring someone’s thoughts versus inferring what someone is inferring about someone else’s thoughts).

Knowing more about oneself helps us better understand others. Similarly, knowing about others helps us understand ourselves better. To that extent, mirror neurons do facilitate better self-understanding.

How do mirror neurons develop empathy?

To understand this, we should understand what mirror neurons are. In fact, mirror neurons are defined based on a specific property they have. These are specialised nerve cells, that are active when we perform an action (e.g., grasping a spoon), as well as when we observe someone else perform the same action. This dual-firing property—these neurons fire when we perform an action or observe an action—provides  an internal template to our brains to infer intentions underlying specific actions, in a rather automatic/spontaneous manner. In the above example, our brains will decipher that the spoon is being grasped to eat, clean, feed, etc. In short, these neurons enable us to understand meanings of observed actions in others, thus giving us a peek into the other persons’ mind. It must be understood that this (deciphering thoughts in others) is a fairly universal function in humans and several other social animals, serves evolutionarily salient functions (e.g., deception detection, perspective taking, empathy, imitation-based motor/speech learning, etc.) and is related (not completely causally) to social cognition in empirical experiments conducted in humans.

To be empathetic, there must be seamless harmony between the three: at the level of neurons, as in getting the intuitive feel of the mental state of the other person; at the level of person, the experience, as in being in self-aware; at the level of action and response, as in initiating some action to alleviate or mitigate the pain or sadness. Could you explain how these processes work and suggest ways of promoting it?

Empathy is a complex emotional blend that includes interpreting emotions in others, experiencing a resultant emotion of the same quality and a feeling of goodwill. There are perhaps automatic and reflective components to empathy from a neurobiology perspective. The automatic, spontaneous (not under conscious control) component is likely to be supported by mirror neuron driven simulatory processes (understanding intentions behind observed actions by replaying the action subconsciously in our minds, as if we are performing the actions ourselves). In other words, we use our knowledge of ourselves to understand the outer world. In contrast, the more controlled, reflective component is supported by the mentalizing system of the brain that includes medial prefrontal cortex, precuneus and the temporoparietal junction. Now, this gives us better insights into how one can facilitate empathy. We perhaps need different strategies to activate the mirroring and mentalizing systems. Future research needs to examine if activating one system improves the functions of the other. Social cognitive enhancement therapies, intranasal oxytocin, yoga, mindfulness-based therapies, brain stimulation and controlled/guided social stimulation are potential avenues towards this goal.

How do they help with language acquisition?

Mirror neurons are perhaps a necessary component of language development through their role in imitation. As children, when we hear and see others speak, the mirroring brain resonates and facilitates imitation. This imitation happens at both implicit and explicit levels. The latter is seen in developing children as they start learning languages.

Could kids, especially kids with autism, be taught more beneficially by a mirror neuron-centric approach?

Autism is a neurodevelopmental disorder with poor social interactions, repetitive behaviours and poor language development. One of the several theories of parsimoniously understanding all the symptoms of autism from a neurobiology stand-point is the broken mirror hypothesis (mirror neuron function is not efficient enough). Based on this, researchers have begun using imitative exercises to sharpen their mirror neuron system. One such imitative exercise is yogasana. Here, especially, when performed in groups, we see others perform the same asanas as we are. In other words, we imitate others and observe others imitating us. Research has shown that this enhances oxytocin-driven brain activity in important social brain regions. Our ongoing experiments are trying to understand this link between imitation through yogasana, mirror neuron activity and oxytocin levels in schizophrenia—another  neurodevelopmental disorder with prominent social cognition deficits.

We have proposed a framework in which mirror neurons are aberrant in schizophrenia. We propose that the more persistent problems of schizophrenia (social cognitive deficits, negative symptoms like aloofness, anhedonia(unable to feel simple joys) and amotivation, poor self-monitoring are linked to a deficient mirror neuron system activity. The brain goes through compensatory or regulatory processes that then trigger phasic heightened mirror neuron system activity which can perhaps explain the phasic (episodic) hallucinations, mood symptoms, and catatonic symptoms. 

We have some empirical evidence for parts of this framework. Researchers from other laboratories have also started investing their time and effort in replicating parts of this framework.

There are several ongoing experiments using yogasana and brain stimulation to potentially activate the mirror neuron system. These are still underway and no clear clinical recommendation can be made at this juncture. We still have a long way to go in order to understand and apply this knowledge in clinical practice.

What is the methodology of your research?

This is a very broad question. Research with human subjects is done according to standard ethical principles, supervised and approved by the institute’s ethics committee. I will focus on the main methods used. Consenting participants first go through a detailed clinical assessment to record and quantify their symptoms and real-world functioning. This is followed by cognitive assessments (including the use of SOCRATIS—which uses picture-sequence based stories, video clips and questionnaires to tap into social information processing). Next, subjects go through either fMRI (brain scans to identify brain activity during specific tasks) or Transcranial Magnetic Stimulation (brief magnetic-pulse-evoked brain activity during observation of static images and goal-directed actions) to study indirect activity within the mirror neuron system. Difference in brain activity while observing actions relative to static images gives an indirect quantification of mirror neuron system activity. Please note, direct measurements are not easily possible in humans (done usually in monkeys), because it requires placing electrodes in the brain in live subjects.

Statistical techniques are then applied to understand the relationship between brain activity, social cognitive processes, symptoms and real-world outcomes.

And what are the inferences from these studies?

Schizophrenia patients experience social disability in terms of real-world functioning, like relationships and employment. This is partly explained by their social cognition deficits. To understand the neural basis of these deficits, we conducted TMS-based experiments to tap into mirror neuron system activity. We found that mirror neuron system activity was reduced in schizophrenia patients and this significantly correlated with their social cognition deficits. Our current line of investigations include methods  to enhance mirror neuron system activity, which could in turn improve social cognition and hence quality of life of patients with schizophrenia and their families.

 Sociopaths, psychopaths, pathological narcissists, megalomaniacs—surely they do have mirror neurons.

 Any comments on this will be purely speculative. Very little empirical research. Schizophrenia and autism are the two disorders in which this has been examined systematically.

A lot of debate surrounds “action understanding”. Could you explain the central role and supporting role of mirror neurons here?

Understanding intentions behind actions is a central aspect of accurate social cognition. Actions are movements of body parts that serve an underlying goal or purpose. Mirror neurons provide a template to the observer, partly based on past learnt (performed/observed) experiences, to decipher intentions underlying observed actions in others as if they were being performed by oneself. Though some researchers suggest that this understanding arises out of a theoretical (propositional) or simulatory (pretence-based) process, the role of mirror neuron driven embodied simulation perhaps contributes to the initial, reflexive understanding of intentions underlying observed actions.

We are now working on three aspects of the mirror neuron system—(a) factors regulating the mirror neuron system (e.g., emotional context, motivation, meaningfulness of observed actions, disease states, etc.); (b) techniques to enhance mirror neuron system activity, and hence social cognitive processes through Yoga and Transcranial Magnetic Stimulation and (c) utilising pre-treatment mirror neuron system activity in predicting response to conventional medical treatment of schizophrenia. 

What have you learnt so far?

Exploring how the brain supports complex human behaviour is undoubtedly fascinating. The evolutionary biology driven social brain hypothesis of schizophrenia and autism prompts us to examine important sub-systems of this social brain. The mirror neuron system, since the time of its discovery in the early 1990s has been a fascinating avenue. Despite the overzealous hype around this concept, it certainly has relevance ranging from understanding how we behave (e.g., twitching our legs when a football goal is missed to automatically crying when we see a near one in tears) to how the brain misfires in severely disabling neuropsychiatric disorders. The challenge ahead will be to replicate our initial findings and test our theoretical framework using novel neuroscience techniques to derive a critical and mechanistic understanding of how the brain processes social information. This can then be translated to better treatment opportunities for the severe diseases mentioned earlier.

What’s the current research and understanding of mirror neurons?

 After the initial overzealous attribution of several brain functions to mirror neurons, necessitating the description “the most overhyped concept in neuroscience”, there has been a more controlled, incremental exploration of this system using novel neurobiological investigations.