Identification of key brain regions of social gaze

Summary: Researchers have discovered two brain regions crucial for social gaze in primates. Stimulation of the orbitofrontal cortex increased eye contact duration and responsiveness, while the dorsomedial prefrontal cortex influenced long-term gaze patterns. These findings may inform therapies for social behavior problems linked to disorders like autism.

Highlights:

1. Stimulation of the orbitofrontal cortex stimulates immediate social gaze behaviors.
2. Stimulation of the dorsomedial prefrontal cortex affects long-term gaze interaction patterns.
3. The findings could lead to therapies improving social attention in autism.

Source: Yale

For animals like primates, the act of looking plays a key role in social interaction, used to both send and gather information. In a new study, Yale scientists discover two regions of the brain that contribute to this type of social attention.

The findings provide important insights into how this dynamic behavior appears and could be used to boost social behavior in disorders like autism in which it can be difficult to attract social attention, the researchers say.

The results were published on May 31 in the journal Neuron.

For primates, social gaze is an integral part of social interaction, says Steve Chang, associate professor of psychology and neuroscience at Yale's School of Arts and Sciences and lead author of the study.

“For example, monkeys want to see what others are looking at because there might be more resource opportunities,” Chang said.

“But prolonged eye contact could also be a threatening gesture. So there's this complex balance between looking at other people's eyes to get information without sending bad information.

In a previous study, Chang and colleagues identified brain regions in the prefrontal-amygdala brain networks where neural activity increased when monkeys looked at each other. For the new study, they wanted to determine the extent to which these regions caused social gaze behavior.

To do this, the researchers paired two rhesus macaque monkeys together, then used infrared cameras to track the position of the two monkeys' eyes. When one of the monkeys looked at the other's eyes, it received a small, real-time stimulation in one of three brain regions. The researchers then tracked whether and how the stimulated monkey's gaze changed.

They found that after receiving stimulation in one of the regions – a prefrontal cortical region called the orbitofrontal cortex – the monkeys' spontaneous glances were more focused around their partner's eyes for the next few seconds and the time between glances was much shorter than that of monkeys. who did not receive stimulation.

“Stimulation in this region also reduced the time it took for one monkey to reciprocate another's gaze,” Chang said. “But none of these findings occurred when the monkeys were in a nonsocial interaction, looking at a moving dot rather than at the eyes of another monkey.”

Stimulation in the other two brain regions – the dorsomedial prefrontal cortex and the anterior cingulate cortex gyrus – did not produce the same effects.

However, stimulation of the dorsomedial prefrontal cortex had a unique long-term effect not observed in other regions. During the stimulation sessions, which lasted 1.5 hours, stimulation of the dorsomedial prefrontal cortex changed the way gazes were exchanged between two monkeys.

“The partner monkeys' gazes interacted over time in a sort of leader-follower pattern,” Chang said.

“Over the course of stimulation, this relationship strengthened, but only with stimulation of the dorsomedial prefrontal cortex.”

Together, the results reveal the important contributions that these two brain regions offer to both momentary and long-term social gaze interaction. Knowing how these regions contribute to social interactions, and particularly social gaze, reveals where interventions could be focused to boost social behavior where it is diminished, Chang said.

“We can envision a future therapeutic approach that builds on these findings using a social brain-computer interface,” he said, “where we target these regions to improve social attention in the moment and over time. term.”

About this news in social neuroscience and vision research

Author: Mallory Locklear
Source: Yale
Contact: Mallory Locklear – Yale
Picture: Image is credited to Neuroscience News

Original research: Closed access.
“Closed-loop microstimulations of the orbitofrontal cortex during real-life gaze interaction enhance dynamic social attention” by Siqi Fan et al. Yale

Abstract

Closed-loop microstimulations of the orbitofrontal cortex during real-life gaze interaction improve dynamic social attention

Strong points

• Closed-loop microstimulation was applied based on the other's gaze.
• OFC microstimulations improved momentary spatial and temporal social attention
• dmPFC microstimulations affected longer-term interindividual gaze dynamics
• The primate prefrontal cortex has causal nodes to control dynamic social attention

Summary

Neurons in several prefrontal areas encode several key variables in social gaze interaction. To explore the causal roles of the primate prefrontal cortex in real gaze interaction, we applied weak, closed-loop microstimulations precisely triggered by specific social gaze events.

Microstimulations of the orbitofrontal cortex, but not of the dorsomedial prefrontal cortex or anterior cingulate cortex, improved dynamic momentary social attention in the spatial dimension by decreasing the distance of fixations from a partner's eyes and in the temporal dimension by reducing the interval between glances. and the latency to reciprocate the directed gaze of the other.

On the other hand, on a longer time scale, microstimulations of the dorsomedial prefrontal cortex modulated the dynamics of interindividual gaze in relation to one's own gaze positions.

These results demonstrate that several regions of the primate prefrontal cortex can serve as functionally accessible nodes to control different aspects of dynamic social attention and suggest their potential for a therapeutic brain interface.