
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.
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.