Harvard scientists: Control a rat with your brain

We're not quite at the stage where we can communicate brain to brain with our fellow humans, but we may be on our way to communicating with other species. Or at least controlling them, thanks to a new, non-invasive interface developed by scientists at Harvard Medical School.

A team led by Seung-Schik Yoo, an assistant professor of radiology, has created a brain-to-brain interface (BBI) that allows a human controller to move a portion of a rat's body just by thinking about it, all without invasive surgical implants.

Brain-to-computer interfaces (BCIs) are becoming more common; that is, interfaces that allow a human to control a computer or gadget with thought using electroencephalography (EEG). A bi-directional interface -- one that allows communication from the computer back into the brain -- is a little trickier; without applying some sort of physical stimulation, it's impossible for a computer to force a brain to send out the signals that control limb movement, for example.

This is where focused ultrasound (FUS) comes in. It delivers focused acoustic energy to a specific point, and is usually used to heat and destroy diseased or damaged tissue, such as tumors, in hard-to-reach places such as the deeper regions of the brain. Yoo's team, however, has found that a lower-intensity blast can be used to stimulate brain tissue without damaging it.

So here's how it works. The human controller is hooked up to an EEG-based BCI, while the rat is hooked up to an FUS-based computer-to-brain interface (CBI). The process starts with Steady State Visually Evoked Potentials. The human views an image of a circle flashing in a specific pattern, and this generates electrical brain activity in the same frequency. When the BCI detects this activity, it sends a command to the CBI, which in turn sends FUS into the region of the rat's brain that controls its tail, causing it to move.

Using six different human subjects and six different rat subjects, the team achieved a success rate of 94 percent, with a time delay of 1.59 ± 1.07 seconds between user intention and the rat's response.

This isn't the first time brain-to-brain communication has been successfully achieved with rats. Earlier this year, Miguel Nicolelis at the Duke University Medical Center developed a BBI that allowed rats to transmit their thoughts to each other.

What could you do with a mind-controlled animal? Well, our first thought was little monkey butlers, but on a more practical level, they could be used for environmental surveillance and search and rescue. It's still very early days, though, and we hope there's enough time to iron out the ethical concerns.