Neurobiology of conversation: Brain activity depends on who you’re talking to
Our brains respond differently when talking to a person from a different socioeconomic group than during a conversation with someone of a similar background, a novel new imaging study shows.
While neuroscientists have used brain imaging scans to track in great detail neural responses of individuals to a host of factors such as stress, fear, addiction, and even love and lust, new research shows what happens in the brains of two individuals engaged in a simple social interaction.
The study, published in the journal Social Cognitive and Affective Neuroscience, reveals the distinct neurobiology of a conversation between two people of different backgrounds.
“When a Yale professor talks to a homeless person, his or her frontal lobe activates a different neural network than if they were chatting with another colleague,” said senior author Joy Hirsch, the Elizabeth Mears and House Jameson Professor of Psychiatry and professor of comparative medicine and of neuroscience. “Our brain has apparently designed a frontal lobe system that helps us deal with our diversity.”
Hirsch has a joint appointment in neuroscience at the University College of London.
The study is the brainchild of recent Yale graduate Olivia Descorbeth, who first proposed the research idea as a high school student. Hirsch and Descorbeth wanted to know if a person’s brain responds differently when speaking with individuals from different socioeconomic backgrounds.
They enlisted 78 individuals with different family income and educational levels from the New Haven, Connecticut area and selectively paired each subject with multiple partners to minimize the impact of race and gender on the results. In each experiment, both subjects were connected to a novel neuroimaging system called functional near-infrared spectroscopy (fNIRS), which tracks the brain activity of both subjects. Then they were instructed to have a casual conversation.
The researchers found that in both subjects the activity in the left dorsolateral prefrontal cortex, which is involved in control of cognitive processes, was much higher when they talked with someone from a different socioeconomic background than with someone of similar status.
Descorbeth said paired imaging studies can also be used to examine the effects of race and gender on brain activity. “It is theoretically possible that time and training can minimize or even eliminate how our brains respond to people not like ourselves,” she said.
“There is a neurobiology of socialness, and neurobiology allows us to modulate our response to diversity,” Hirsch said. “We want to be inclusive, we want equity, and theoretically, neuroscience can say something about how we can achieve that.”