The eyes have it: Mutual gaze potentially a vital component in social interactions
News Dec 16, 2015
Researchers at Japan's National Institute for Physiological Sciences showed that eye contact is essential for face-to-face interactions; without it, certain brain activities cannot be stimulated to establish connectivity between people -
A person in love gazes longingly and attentively at the object of his or her desire. When we want to grab another person's attention, we look directly into their eyes. Why do we behave this way? What happens during our gazing?
Researchers at the National Institute of Physiological Science (NIPS) have revealed that mutual eye contact synchronizes spontaneous activity in specific areas of the brains of two interacting parties. The finding indicates that this synchronized brain activity is crucial in establishing and facilitating face-to-face social interaction.
In most cultures, we are taught from a young age to maintain eye contact when we speak. Failure to do so may be considered impolite, and can even risk losing the other party's attention. As it turns out, eye contact is fundamental in all human face-to-face interactions. The mechanisms of visual attention through eye contact maintained between two people (mutual gaze), and toward a third person or an object (joint attention), have been extensively studied. However, the underpinnings of the attention being shared and retained have remained unclear.
To further explore this topic, the NIPS team enrolled 96 volunteers who were not mutually acquainted, and conducted a series of tests to investigate the brain activity during situations with sustained eye contact.
Three sets of experiments were conducted over 2 days. Participants were paired with different partners and instructed to hold each other's gaze in real time under various conditions. The researchers used functional magnetic resonance imagining to monitor the brain activity that took place during mutual gaze. Takahiko Koike, the study's first author, explains: "We expected that eye-blink synchronization would be a sign of shared attention when performing a task requiring joint attention, and the shared attention would be retained as a social memory." They also expected that the right inferior frontal gyrus (IFG) in the brain would be activated by both the initiator and the respondent to the gaze.
Indeed, the researchers detected synchronization of eye-blinks, together with enhanced inter-brain synchronization in the IFG, in the pairs when eye contact was established. Compared with findings from previous studies, these outcomes show that synchronization of eye-blinks is not attributable to a common activity, but rather to mutual gaze. This indicates that mutual eye contact might be a crucial component for human face-to-face social interactions, given its potential to bind two individuals into a singular connected system. This topic warrants further investigation to truly understand what is at work behind interpersonal communications.
"Based on the enhancement of behavioral and neural synchronization during mutual gaze, we now know that shared attention is hard to establish without eye contact," Norihiro Sadato, senior author of the study, says. "Further investigation into the workings of eye contact may reveal the specific functional roles of neural synchronization between people."
Note: Material may have been edited for length and content. For further information, please contact the cited source.
Koike T et al. Neural substrates of shared attention as social memory: A hyperscanning functional magnetic resonance imaging study. NeuroImage, Published January 15 2016. doi: 10.1016/j.neuroimage.2015.09.076
Adult depression has long been associated with shrinkage of the hippocampus, a brain region that plays an important role in memory and response to stress. Now, new research has linked participation in team sports to larger hippocampal volumes in children and less depression in boys ages 9 to 11.
Researchers have discovered a brain process common to sleep and ageing in research that could pave the way for new treatments for insomnia. The scientists report how oxidative stress leads to sleep. Oxidative stress is also believed to be a reason why we age and a cause of degenerative diseases.READ MORE
Patients in a new Northwestern Medicine study were able to comprehend words that were written but not said aloud. They could write the names of things they saw but not verbalize them. This provides an insight into the brain degeneration that defines the rare dementia termed primary progressive aphasia.