NIR Spectroscopy -- A Noninvasive Mind-Reader?

April 21, 2009

Canadian researchers at the Bloorview Research Institute (Toronto, ON, Canada) and the University of Toronto have developed a way to use optical imaging to decode preference by measuring the intensity of near-infrared light absorbed in brain tissue.

Canadian researchers at the Bloorview Research Institute (Toronto, ON, Canada) and the University of Toronto have developed a way to use optical imaging to decode preference by measuring the intensity of near-infrared light absorbed in brain tissue. Brain–computer interface (BCI) systems like this could enable people with severe or multiple disabilities to communicate and control external devices via thought alone.

The system is based on the use of near-infrared spectroscopy (NIRS) to study cerebral hemodynamics during the decision-making process. NIRS has been investigated before as a non-invasive tool for reading thoughts. But previous NIRS-BCI setups required user training. For example, to indicate “yes” to a question, a subject would need to perform a specific unrelated task, such as a mental calculation. The key difference in this latest system is that the BCI is trained to directly decode neural signatures corresponding to specific decisions. Because no secondary task is required to indicate preference, the design should be more intuitive to use, decreasing the cognitive load required to operate the interface and removing the need to train the user.