Monkeys' brains synchronize as they collaborate to perform a motor task: Levels of synchronicity in motor cortex are influenced by proximity, social status -- ScienceDailyDuring one task, one monkey, called the passenger, sat in an electronic wheelchair programmed to reach a reward across the room, a fresh grape. A second monkey, the observer, was also in the room watching the first monkey's trajectory toward the reward. Electrical activity in the motor cortex of each monkey's brain was recorded simultaneously. An analysis showed that when the passenger traveled across the room under the attentive gaze of the observer, pools of neurons in their motor cortices showed episodes of synchronization. The researchers found these episodes of interbrain cortical synchronization (ICS) could predict the location of the passenger's wheelchair in the room, as well its velocity. The brain activity could also predict how close the animals were to each other, as well as the passenger's proximity to the reward. The most compelling finding, they said, was that ICS could predict another key social parameter -- the rank of the monkeys in the colony.