By combining behavioral and wireless eye tracking and neural monitoring, a team of scientists studied how pairs of freely moving macaques interacting in a naturalistic setting use visual cues to guide complex, cooperative behavior.
Eye contact and body language are critical in social interaction, but exactly how the brain uses this information in order to inform behavior in real time is not well understood.
"Until now, we didn't know how what we are looking at guides our decision to cooperate or not, because of our inability to measure oculomotor events and correlate them with what neurons are doing in that instant. Because the technology was not there, that knowledge was just unattainable." In the experiment, two pairs of macaques were observed over the course of several weeks as they learned to work together for food reward. Each trial had the monkeys moving freely about an enclosure, separated by a clear divider. The monkeys had previously learned that pressing a button causes a snack tray to come within reach, but during trials, this only happened if the animals pressed the button simultaneously.
"They deserve a lot of credit," said Aazhang, who also serves as director of the Rice Neuroengineering Initiative and co-director of the Center for Neural Systems Restoration.