Eye contact and body language are important in social interaction, but how the brain uses this information to inform behavior in real time is not well understood.

By combining behavioral and wireless eye-tracking and neural monitoring, a team of Rice University scientists and colleagues studied how pairs of macaques moving freely in a natural environment guide complex, goal-directed cooperative behavior. Use visual cues to Published in the study The nature The first provides evidence that the part of the brain that processes visual information — the visual cortex — plays an active role in social behavior by providing an executive area — the prefrontal cortex — that guides the decision to cooperate. deals with the signals necessary to generate

“We are the first to use telemetric devices to record neural activity from multiple cortical populations in the visual and prefrontal cortex while animals explore their environment and interact with each other,” said Valentin Dragoi, who That Rice and computer engineering professor of electrical and computer engineering said. Rosemary and Daniel J. Harrison III Presidential Distinguished Chair in Neuroprosthetics at Houston Methodist. “When primates, including humans, communicate, we make eye contact and use body language to indicate what we want to do.

“Until now, we didn’t know whether what we were seeing guided our decision to cooperate or not, because of our inability to measure our oculomotor events and what the neurons were doing at the time. It doesn’t fit in. Because the technology wasn’t there, that knowledge was just unattainable.”

Much of what neuroscience has learned about the neural bases of cognition began with studies in which animals were restrained and performed in isolation in response to artificial stimuli on a computer screen rather than that during actual interactions with peers in a more natural setting. The ability to track neural activity during animal movement and free behavior represents a major step forward in neuroscience research and promises to shed new light on the inner workings of the brain.

“It’s been a dream of neuroscientists for a long time — to record from neurons on the fly while the animal is moving freely,” said Dragoi, who also serves as scientific director of the Center for Neural Systems Restoration. Do Houston Methodist-Rice Venture is dedicated to neuroscience research and therapeutic innovation. “We tracked populations of neurons in the visual cortex — the part of the brain that processes information about vision — and the prefrontal cortex — an executive area that encodes our decisions to perform certain actions. “

In the experiment, two pairs of macaques were observed over several weeks as they learned to work together for a food reward. In each trial the monkeys roamed freely around a wall, separated by a clear divider. The monkeys had previously learned that pressing the button led to the snack tray, but during trials this only happened if the animals pressed the button simultaneously. As the macaques’ cooperation skills improved, the frequency with which they elicited socially relevant cues – their partner, the snack tray – was found to increase before their performance in concert.

“This technology allows us to distinguish between active and passive approaches,” Dragoi said. “Active approach occurs when we act on a stimulus that we are looking at with a goal in mind. When I engage in social interaction, I act in some way, extract visual information and use that information for coordination. The search involves looking at how a population of sensory neurons extracts information, transmits it to an executive area, and how it becomes real. Synchronize in time to advance the decision to cooperate.”

Dragoi and Behnaam Aazhang, Rice’s JS Abercrombie Professor of Electrical and Computer Engineering, both emphasized the significant contributions of the study’s lead author, Melissa French, a former Ph.D. student in Dragoi’s lab and now a postdoctoral researcher at Baylor College of Medicine, and Sudha Yellapantola, a former Rice doctoral student in Azhang’s group who now works as a research professional in the health care industry.

“They deserve a lot of credit,” said Azhang, who also serves as director of the Rice Neuroengineering Initiative and co-director of the Center for Neural Systems Restoration.

“This work is very interdisciplinary and involves a complex experimental design aimed at testing the hypothesis that the visual frontal cortex has an important role in social behavior,” Azhang added. “Many animals are not very social, but primates are, which was an important factor in the research, given the nature of the hypothesis.”

It turns out that expressions like “staring daggers” and “eye-to-eye” aren’t just quirks of the English language: we now have evidence that the visual cortex and prefrontal cortex are involved in achieving complex behaviors. works in concert. Cooperation

This research was supported by the National Institutes of Health (U01NS108680, 1F31MH125451).