In our last Research Lead, we described how a human was able to move the tail of a rat through brain-to-brain interface. Now, Rajesh Rao and Andrea Stocco at the University of Washington have successfully performed what they believe is the first non-invasive human-to-human brain interface. Their interface was set up as follows: A “sender” wore a headset that read the electrical waves along his scalp. His brain waves were then interpreted by computer software, and when he properly produced a certain type of brain wave (by entering a focused and relaxed brain state), a computer via transcranial magnetic stimulation (TMS) sent a signal to the “receiver’s” brain, which caused the receiver to involuntarily press a button on a keyboard. The key component of this interface was the use of TMS. There was a small TMS machine hooked up to the receiver’s motor cortex such that, when the machine was activated, the receiver experienced an involuntary motor movement. While this type of research is billed as a human brain-to-brain interface, it might be better described as a brain-to-computer-to-TMS-to-brain interface. Regardless, Rao’s and Stocco’s work represents a significant step towards more direct brain-to-brain interaction.