Exploring the Dark Matter of Neuroscience: Interbrain Synchrony
By: Mariam Jabara
Tags: Neuroscience, Relationships, Human Behavior, Psychology, Social Psychology

What is interbrain synchrony, and how does it impact human connection?

At a recent conference, Montreal AI & Neuroscience (MAIN), I was introduced to an area of research that could further unlock how the human brain functions in social situations. This area of research refers to the dark matter of neuroscience in social interaction.

The field is now expanding to couple with Artificial Intelligence as Social Neuro-AI:

“Social Neuro-AI starts with computational social neuroscience, and we look at how we can use social neuroscience towards artificial intelligence.” — Dr Guillaume Dumas — From Social Physiology to Social Neuro-AI, MAIN-2020

Let’s dive in, shall we?

I recently came across a paper written by Amir Djalovski, Guillaume Dumas, Sivan Kinrich, and Ruth Feldman on Human Attachment and Interbrain Synchrony (2020). Before I share with you my takeaways, we need to set the context. According to the scientific work of Dunbar (2014) and Hari and Parkko (2015):

Through evolution, humans have undergone an expansion that allows human brains to synchronize with each other when performing complex social tasks.

When does neural synchrony develop, you might wonder? According to the work of Feldman (2017), it develops from the parent-infant bond. From infancy, our brains start to synchronize with others, and this continues as we age and begin to engage in more complex, less familiar social interactions.

Jumping back to the work of Djalvoski et al., this study focuses on examining how the brains of male-female pairs (long-term couples, best friends, and strangers) synchronize during two important social tasks.

Motor Coordination (Drawing an object together on an Etch-A-Sketch) Empathy Giving (Each person sharing a distressing event) * Let's focus on this one. ⭐️

Experimenters examined both:

Behavioural synchrony (Physical coordination that occurs when synchronizing one’s behaviour with another 🤝)

(Physical coordination that occurs when synchronizing one’s behaviour with another 🤝) Neural synchrony (Synchronizing of their brain waves 📈)

Amongst the many findings in this study, it was observed that:

In the Empathy Giving task, couples showed the highest behavioural synchrony with the lowest neural synchrony, while strangers exhibited the opposite pattern.

Illustration by Maayan Harel, Via: Human attachments shape interbrain synchrony toward efficient performance of social goals (Amir Djalovski, Guillaume Dumas, Sivan Kinrich, and Ruth Feldman, 2020)

This is interesting. You might have intuitively thought “wouldn’t the synchrony of brain waves between couples be higher during an empathy-giving situation?” Let’s unpack why this wasn’t the case here. It relates to a concept called complementarity:

Complementarity, a pattern found in interactions with attachement partners beginning in adolescence. It is characterized by an increase (⬆️) in behavioural synchrony and a decrease (⬇️) in neural synchrony. In infancy, an opposite pattern called linkage is observed. Characterized by an increase (⬆️) in behavioural synchrony and an increase (⬆️) in physiological (including the 🧠) synchrony.

Among couples, a long-term attachment bond is already formed. In this study, it’s suggested that the goal, evolutionarily speaking, is to strengthen the relationship and foster anabolism: the process by which the brain’s neural activity & vigilance decreases to promote its rest, repair and growth (Schulkin and Sterling, 2019).