The brain science of social interactions
Every social interaction we have activates our brain circuits, enabling us to read other people’s emotions, understand their intentions and respond appropriately.
In people with schizophrenia, the ability to interact socially can be impaired. Underlying changes to these brain circuits or networks can affect social functioning. Understanding these changes is a major focus of research at CAMH’s Campbell Family Mental Health Research Institute.
Dr. Colin Hawco, Project Scientist, and Dr. Aristotle Voineskos, Director of the Slaight Family Centre for Youth in Transition, recently published a brain imaging study in the journal Scientific Reports that sheds light on how brain networks are related to different types of social interactions. This initial study also laid the groundwork for a much larger multi-site initiative, the Social Processes Initiative in Neurobiology of Schizophrenia (SPINS), funded by the U.S. National Institutes of Health. Here, they describe the initial study.
Why is it important to study brain networks in relation to social behaviours – particularly for mental illnesses?
Dr. Voineskos: When your ability to interact with others is impaired, it can have a profound and substantial effect on your life. In people with schizophrenia, we can clearly see that as a person’s social impairment becomes more severe, it is more likely the person will be isolated and unable to function in daily life. To date, there is really no effective treatment to deal with these social impairments.
Since treatment development has stalled, we’re really invested in figuring out the brain networks of social behaviours. We can then target those networks in treatment studies, and test whether a new intervention changes brain function. It’s much like testing whether a new heart intervention changes heart function. Ultimately this will contribute to a better quality of life for people with schizophrenia.
What did you do in this initial study?
Dr. Voineskos: We drilled down to look at the relationship between brain networks, and specific types of social behaviours.
Social interaction is really one of the most fascinating and important domains of human behaviour. It begins in infancy. When a baby imitates her or his mother’s smile, it activates a system of “mirror neurons” inside the baby’s brain. The mirror neuron system is what enables the development of imitative play, and likely also facilitates language development. It’s been studied a fair bit already in autism. But we’ve started to realize it’s also really important in schizophrenia.
As we age, our interactions become more complex. We can perceive and interpret others’ actions and intentions, and infer their states of mind. We can detect sarcasm or deception. These social interactions are the foundation of all our relationships, and enable us to function in our daily lives.
These two types of social behaviours – basic facial emotion imitation and more complex social exchanges – have been shown to activate different parts of the brain. In the scientific world, they’ve been described as “low-level” and “high-level” social networks, respectively. And they were largely considered separate processes until now.
In our study, we looked at the activation of the brain while people were imitating facial emotions in the scanner. Out of the scanner we had people complete simpler and more complex social tasks.
How did you study this?
Dr. Hawco: We ran a series of tests in which study participants looked at photos or videos of people, and answered questions about the emotions or intentions they perceived. These tests were carefully designed to measure social functioning in relation to the “low-level” and “high-level” networks.
The first set of tasks assessed a person’s ability to judge emotional states. The simplest task was asking people to recognize basic facial emotions. Then to make things a bit more difficult, we had participants view photographs only of people’s eyes, and then decide the person’s state of mind. (Try the eye test yourself.)
Source: Reading the Mind in the Eyes Test, Autism Research Centre, Department of Developmental Psychiatry, University of Cambridge
In another set of tests, participants watched videos of actors portraying different emotions and were asked to describe these emotions. In yet other videos, two actors interacted in either sincere or sarcastic ways. Again, participants had to answer questions on what they believed actors were doing or meant.
Based on responses to these and other tests, we developed scores of their social-cognitive abilities.
At the next stage, while in the brain scanner, participants were shown photos with five different facial expressions. First, they had to imitate the expression, and then they had to simply observe. We looked at patterns of brain activity and social responses using a type of brain imaging called functional MRI.
What did you find?
Dr. Voineskos: All networks were activated, even with the simple “low-level” imitation task. We also found that people’s ability to imitate or mirror emotions in the scanner was related to their social and cognitive abilities, which had been measured in the more complex “high-level” tasks outside of the scanner.
How does this fit into your larger research initiative?
Dr. Hawco: We are applying this approach to study brain circuitry and social functioning of people with schizophrenia. This initial study was based on results from 20 people with no schizophrenia diagnosis. We’re now completing a much larger study with 160 people recruited at CAMH, and 480 in total across three North American sites, both with and without schizophrenia. This will be the largest-ever brain imaging study of social function.
We wanted to include people with schizophrenia who have good social functioning, and people without schizophrenia but poor social functioning. We can then see how these brain networks function in relation to social skills and functioning, as well as real-life outcomes such as employment and education, across different diagnoses.
We recently worked out an approach to examining this issue based on the patterns of brain activity, rather than on diagnosis. A big issue in psychiatry is the sheer variability of results. If you think about it, this makes a lot of sense: our brains are different from one another, whether or not you have a mental health issue. So now we are changing approaches. Rather than comparing people with a mental illness to those without, we are letting the brain imaging data tell us which participants look similar.
Our larger study is almost done. We’re starting to see some interesting results that show that social and cognitive abilities are not based on whether or not a person has schizophrenia – but are tied to how brain networks operate.
The results should be out in the near future – stay tuned!