A group of researchers studying the brain activity of singing male and female red-tailed wrens found that the species synchronized its singing by suppressing areas of its partner’s brain.

The researchers say the auditory feedback that the red-tailed wrens exchange suppresses some of their brain regions, helping to coordinate singing, making it almost telepathic.

Research on wrens has shown that for any good collaboration, partners must literally become one through sensory connections.

Eric Fortune, study co-author and neuroscientist at the Division of Life Sciences of the New Jersey Institute of Technology

Duet wrens have a clear song structure that partners know in advance, but in the process, they must quickly coordinate their actions, receiving constant feedback from the partner.

During the work, the team took neurophysiological recordings of four pairs of wrens as they sang solo and in duet: they then analyzed sensorimotor activity in the premotor region of the bird’s brain, where specialized neurons are active for learning and making music.

Recordings showed that during the singing, the voices of the birds sounded so similar that it seemed as if one bird was singing. The team then listened to tapes of the duo of wrens while they were in a dream-like state. The birds were anesthetized with a drug that targets the main inhibitory neurotransmitter in the brains of wrens, which is also found in humans, gamma-aminobutyric acid (GABA). The drug transformed activity in the brain, from inhibition to bursts of activity when wrens heard their own music.

These mechanisms are common or similar to what happens in our brain. The authors say the results provide new insights into how the brains of humans and other cooperating animals use sensory signals to act in concert with one another.