Close Relationships Facilitate Efficient Performance of Social Goals
Post by Lincoln Tracy
What's the science?
Humans are inherently social creatures with complex social skills. Neuroscientific models hypothesize that our brain has undergone substantial changes as we have evolved to become more social. The extent to which social behaviors are embedded in the human brain suggests that the brain operates by responding to natural and dynamic social exchanges to a greater degree than static or non-social stimuli. Consequently, social neuroscience research is focusing more on how brains synchronize during naturalistic social moments to achieve specific goals. Specifically, modern research utilizes hyperscanning, a method where data is collected simultaneously from two or more brains to measure synchronous activity. This week in NeuroImage, Amir Djalovski, A Ph.D. student at Ruth Feldman's lab sought to test how different types of relationships affect neural synchronization, by using electroencephalography (EEG) hyperscanning while partners completed various tasks.
How did they do it?
The authors recruited 158 adults (79 male-female pairs) organized into one of three groups: couples (long-term romantic partners who had been living together for at least a year), friends (close friends), or strangers (demographically matched individuals who did not know each other). Both participants had an EEG cap placed on their heads for simultaneous recording of brain activity. Participants then engaged in two naturalistic interactions: a motor task and an empathy giving task. First, participants were given an “Etch a Sketch” and asked to draw predefined pictures while only being allowed to twist one nob each. Then, participants took turns sharing a distressing or troubling experience. After completing the tasks, participants rated how comfortable they felt in each task, and how empathic and helpful they felt their partner was. EEG data was bandpassed to assess brain synchrony in the alpha, beta, and gamma frequency bands. Electrodes on the EEG cap were divided into pre-defined brain areas of interest: left temporal, right temporal, and central. The level of behavioral synchronicity (i.e., social interactions) was assessed for behaviors such as a positive and relaxed mood and the reciprocity of interaction.
What did they find?
Couples displayed higher behavioral synchronicity, higher interbrain synchronicity, and task performance on the motor task compared to friends and strangers. Importantly, the relationship between behavioral and neural synchrony was only moderated by attachment bonds in couple pairs. That is, the greater the behavioral synchrony the higher the neural synchrony (in couples). In the empathy giving task, couples again displayed higher behavioral synchrony compared to strangers. Couples showed the lowest interbrain synchrony during the empathy giving task, while strangers exhibited the highest. However, strangers felt much less supported than couples or friends during the empathy giving task.
What's the impact?
This study shows that natural social processes in the brain are shaped by attachment bonds and sustained by behavioral coordination. Specifically, romantic partners who lived together displayed the most efficient two-brain-two-behavior balance toward best performance. This highlights how attachment bonds shape interpersonal brain processes, and that differences between romantic partners and strangers are not simply the result of familiarity. Rather, other aspects of long-term romantic love contribute to these differences. While the hyperscanning literature is rapidly growing and more research is needed, this study underscores the importance of looking at interbrain processes in order to understand how two brains synchronize during real-life social interactions.
Djalovski et al. Human attachments shape interbrain synchrony toward efficient performance of social goals. NeuroImage (2021). Access the original scientific publication here.