Scientists have for the first time linked the brains of a human and a rat, enabling the man to use just his thoughts to wiggle the rodent's tail.
This is the first case of a brain-to-brain interface between species, and the first example of a non-invasive brain-to-brain interface, researchers claimed.
Early 2013, scientists had linked together the brains of two rats. This first known instance of a brain-to-brain interface apparently helped the rodents share data to accomplish certain tasks, even across intercontinental distances, LiveScience reported.
In the latest experiment, researchers from Harvard Medical School employed non-invasive techniques to link the brains of a human and a rat. The man had electrodes stuck onto his scalp that picked up brain-wave activity.
The rat was placed in a machine that focused ultrasound pulses through its skull to its brain, and was anesthetised so that it would not wriggle its head during the experiment.
The volunteer had a video screen placed in front of him that displayed a flickering pattern of light. If he paid attention to the screen, his brain waves would synchronise with the strobe light.
If he looked away, or even if he looked at it while thinking of something else, his brain waves would not synchronise with the light flickers.
When the man focused on the flickering pattern, that action signalled the ultrasound to stimulate the part of the sleeping rat's brain responsible for moving its body. In response, the rodent flicked its tail.
The interface was accurate 94% of the time, with a time delay of only about 1.6 seconds from the moment the man initiated his intent to the rat tail's wiggling.
"This is the first non-invasive attempt to achieve a brain-to-brain interface," researcher Seung-Schik Yoo, a neuroscientist and bioengineer at Harvard Medical School, told the website.
Yoo noted that brain-machine interfaces are getting increasingly advanced over time, enabling people with paralysis to control robot arms. In the future, interspecies brain-to-brain interfaces could help search-and-rescue operations, Yoo suggested.
The study was published in the journal PLOS ONE.