Researchers at the University of Toronto used near-infrared light shined on a person's brain to "read" the subject's mind and determine which of two drinks they prefer. By reading images of the brain, they decoded the person's drink preference with 80 percent accuracy. According to the biomedical engineers, the technique could someday enable people who are "locked in" to communicate using their minds. Or create a 21st century Pepsi Challenge. From Live Science:
In the beginning of the study, nine adult volunteers rated eight drinks on a scale of one to five.
Then, wearing a headband fitted with fiber optics that emit light into the pre-frontal cortex of the brain, the subjects were shown two drinks on a computer monitor, one after the other, and asked to make a mental decision about which they liked more.
"When your brain is active, the oxygen in your blood increases and depending on the concentration, it absorbs more or less light," Luu said. "In some people, their brains are more active when they don't like something, and in some people they're more active when they do like something."
"New Device Reads Mind" (LiveScience),
"Decoding subjective preference from single-trial near-infrared spectroscopy signals" (Journal of Neural Engineering)