Computer scientist Robert Jacob and biomedical engineer Sergio Fantini at Tufts University in the US have developed the prototype of the headband which transmits light through the forehead and reads brain activity.
The technique for analysing and acting upon brain activity is called functional near infrared spectroscopy, or fNIRS.
A row of small red lights embedded in the headband beams light waves through the skull and onto the prefrontal cortex of the brain.
A computer connected to the headband then gauges the person's level of mental exertion by measuring the amount of light absorbed by the brain, 'The Boston Globe' reported.
A heavily taxed brain draws more blood than one working easily, and therefore absorbs more light. That tells the computer the wearer may be overwhelmed.
The technology could allow a computer to know the precise moment an air traffic controller approaches mental overload.
In a tower full of air traffic controllers wearing headbands, a computer could automatically shift flight assignments, depending on which controllers show higher levels of mental acuity, researchers said.
The possibilities for the brain scanner are not limited to air travel, they added.
The researchers have used the device to generate movie recommendations for wearers, based on how their brains respond to other films.
In another experiment, pianists practiced on an electronic keyboard while wearing the headband. As their brain signals indicated mastery of a melody, a computer added complexity to the songs by playing harmonies.
The headband prototype connects to a desktop computer through two fat cables. Eventually, Jacob and Fantini envision integrating the brain scanner with a wearable computer, such as Google Glass.
They see the technology as part of a future in which humans communicate with computers through thoughts instead of mouse clicks.