Neuroscientists have developed a new technique that enables them
to decode what people are perceiving just by looking at a readout of
their brain signals. This ability to spontaneously decipher human
consciousness in real-time could have wide-ranging implications,
potentially leading to novel treatments for brain injuries or helping
people with
locked-in syndrome to communicate.
The researchers collaborated with seven epilepsy patients at a
hospital in Seattle, who had a number of electrodes called
electrocorticographic (ECoG) arrays implanted into their brains. These
targeted the
temporal and
occipital lobes of the brain's cortex, concerned with hearing and vision, respectively.
Patients were each shown a series of grayscale images of faces and
houses, which flashed up on a screen in a random order for 400
milliseconds each. Using a novel framework for interpreting subjects’
brain activity data, the researchers were able to tell exactly when each
patient had seen an image, and what that image contained. A report of
this process has been published in the journal
PLOS Computational Biology.
Lead researcher Kai Miller told IFLScience that “there have been
other studies where scientists have been able to tell when a patient is
looking at one type of an image or another, but the timing of this
stimulus had always been known ahead of time.
“However, we were able to decode spontaneously from the signal, so we
were able to look at the brain signal and say at this point in time
they saw this particular type of image.” To achieve this, the team
focused on two types of brain signals:
event-related potentials (ERPs) and
broadband.
Electrodes were implanted into the temporal and occipital
lobes of epilepsy patients, and used to measure their brain activity
when viewing a series of images. Kai Miller, Stanford University
