In our newest line of research we are exploring how people connect with and influence each other. We are investigating this question in a few different ways.  First, we are exploring how the brain understands relationships --who we are close to and how we connect within larger social networks. Second, we are developing a metric of connection based on shared social attention. Third, we are exploring how people shape the way we think.

HOw we know our friends

In our first empirical paper on this topic, we tested whether the brain understands social familiarity as a kind of egocentric distance -- an idea first conceived of by Liberman & Trope (2008).  This idea is certainly consistent with the way we talk about friendship (a "close" friend, he is becoming "distant"). We wanted to know whether these metaphors are a linguistic accident or whether they might echo a common neural machinery. That is, do our brains understand relatively modern concepts like friendship and time by repurposing an ancient computation that evolved to map physical space? This would be efficient if understanding friendship, time, and space all involve computing distance from self in the here and now.  Read the related theoretical paper here.

The "far trial" photo (above) links to a National Geographic article about this studyPhoto: Marian Berryhill

The "far trial" photo (above) links to a National Geographic article about this studyPhoto: Marian Berryhill

To test for a common code, we scanned (fMRI) people as they saw three types of relative distances (pictures of near and far objects, photographs of their friends and acquaintances, and also words referring to the immediate or remote future). We then trained a computer to recognize the participants’ brain pattern when they saw a closer object and the brain pattern when they saw an object further away. We wondered whether a computer that learned the brain patterns evoked by near versus far objects, could then discriminate brain patterns evoked by friends versus acquaintances and by words describing soon vs later time. That is exactly what we found.

Classification of distance, across space, time, and social contexts, was discovered in the right inferior parietal lobe (rIPL).

Classification of distance, across space, time, and social contexts, was discovered in the right inferior parietal lobe (rIPL).

After learning the near and far patterns, the computer could identify when participants were seeing their friends versus acquaintances and whether they were reading words like "now" versus "later." Near-now-dear (near object, soon time, dear friend) trials activated similar patterns in a brain area associated with spatial perception. Far object, later time, and acquaintance trials activated a different pattern, in the same region.  

We also found that the computer did not need to be trained on physical (spatial) distances to get these results -- training in any of the three domains (space, time, social) lead to accurate classification of near vs far in the other domains.

ONGOING RESEARCH:

The Neural basis of social networks

Navigating the social world not only relies upon discriminating friends from acquaintances, but on knowing how other people in our networks connect to each other (e.g., Who are the well-connected "social hubs"?  Who connects diverse groups of people ("social bridges"?). Carolyn Parkinson and I are currently investigating how we perceive these social qualities in others as well as how knowing this information affects the way we think and behave.

how to win friends and influence people

In what ways are we likely to share thought, and what kinds of thought, when shared, are most predictive of friendship? How do thoughts spread from brain to brain? And what individual and situational differences influence that spread?  Carolyn Parkinson, Beau Sievers and I are conducting a series of studies to find out. 

measuring mental CONNECTION

Another way to think about connection is the feeling that comes from knowing that someone understands us.  How and when does that feeling arise and is it accurate?  Is there a measurable, physiological signal of connection that exists when two people share an idea or emotion?  If so, do we use that signal to forge social bonds?  Olivia Kang and I are beginning to investigate these questions by capturing dynamic, physiological markers of shared experience.