The power of thought: interface enables touchless tablet use
Brain-computer junction promises better access for people with paralysis. Paul Biegler reports.
Researchers have created a brain-computer interface (BCI) that, for the first time, allows people with tetraplegia to operate a commercially available tablet with the power of thought alone.
In the study, part of the BrainGate2 clinical trial, two people with Lou Gehrig's disease and one with a spinal injury were able to browse the Web, play YouTube videos, stream music and email or text using an unmodified Google Nexus 9 tablet.
Led by Jaimie Henderson at Stanford University in the US and published in the journal PLOS One, the research used neural decoding software to interpret the brainwaves of subjects, who had electrodes implanted in the part of the brain that controls hand movement.
It works by having the person think about or try to execute a specific movement. This generates characteristic EEG output that is read by a computer as commands to control the tablet cursor via a wireless connection.
By imagining moving a hand, participants could guide the cursor across the tablet screen and by variously attempting to squeeze the hand or flex the arm they could enact a “click”.
The result was a suite of actions that are workaday for most people but life-changing for the three middle-aged subjects, two men and a woman.
The woman, a musician, was able to play a digital piano, browse images of orchids, and email the researchers to tell them that “this research means a lot to me”. One of the men apparently had a penchant for Stevie Nicks, using Pandora to stream her song Landslide. The other man sent his first ever text using the BCI software.
“The tablet became second nature to me, very intuitive,” said the woman. “It felt more natural than the times I remember using a mouse.”
“Amazing!” gushed the Nicks fan. “I have more control over this than what I normally use.”
The research is part of a gathering wave of BCI advances that promises to help people with paralysis, turning an active mind, in essence, into a biological remote control.
It’s worth noting, however, that the world’s most famous sufferer of Lou Gehrig’s disease, the late physicist Stephen Hawking, eschewed a brain-controlled interface in favour of an infrared device that picked up his cheek movement and turned it into signals that controlled a computer.
His reluctance might have had something to do with a large fly in the ointment for the BCI project: you need a brain surgeon to open up the skull to put one in. Even then, there is a natural antagonism between the hard electrodes and squishy brain tissue that leads to scarring and eventual degradation of the signal.
Australian neurologist Thomas Oxley won the 2018 Advance Life Sciences Award for a prototype BCI that might overcome this issue. His “Stentrode” gets into the brain via its blood vessels, where it listens in on brainwaves without any need for open surgery.
The Holy Grail, however, is the non-invasive BCI. US optical scientist Mary Lou Jepsen has signalled that a device fitted over the skull, a bit like a ski cap, could one day sense brain activity with infrared light detectors to allow us to communicate with just our thoughts.
Should that come to fruition, people with paralysis might soon find a more positive answer to a question posed by Stevie Nicks in that haunting song: “I saw my reflection in the snow covered hills, till the landslide brought me down. Can I sail through the changing ocean tides? .... Oh I don’t know.”