24 February 2013

Real-Time Brain Monitoring

Researchers at Tufts University in Medford, Massachusetts, want to give computers the ability to directly monitor human brain in real time performance. The system utilises a headset that beams infrared light from emitters on a user's forehead into their prefrontal cortex, a part of the brain associated with planning and decision-making. Some of the light is absorbed by oxygenated haemoglobin, some by the deoxygenated version of the molecule, and some is reflected back out. By measuring the amount of light reaching receivers on the forehead, the system can tell when a user is concentrating intently or not mentally engaged. Matching the readings to what a user is looking at on a screen allows the system to determine what useful information is and what is getting in the way. The technique, known as functional near-infrared spectroscopy (fNIRS), is a crude brain imager compared with, fMRI. But infrared sensors are cheap and portable and MRI machines are not. Researchers reckon they can glean enough information from their fNIRS rig to turn computers into mind-readers.


As a proof of principle, the system monitored haemoglobin changes while 14 test subjects rated movies listed on the Internet Movie Database. It recorded how each user's brain behaved when rating movies positively and negatively, with greater levels of activity associated with more positive ratings. After this training, the system recommended a list of other movies in turn, with each movie suggestion modified by the brain's reaction to the previous movie suggestion. Not only were its suggestions more acceptable than a random list, but it also improved its results the more it was used. The US Federal Aviation Administration is also exploring the technique to help manage the cognitive workloads of air-traffic controllers. The next step is to build a brain interface that can handle more complex interactions, like filtering emails and the other rivers of information that threaten to overwhelm the modern worker on a daily basis. For now, their set-up can only determine when people are engaged with what they are doing, and when they are not.

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