A team of international researchers has developed a way to look inside people's brains and read their intentions before they even act.

The method was 70 per cent accurate at decoding the intentions of participants from patterns of their brain activity monitored through functional magnetic resonance imaging (fMRI), according to a study.

Activity patterns in the green regions of the brain scan revealed the subjects covert intentions before he began to perform the calculation. From regions marked in red it was possible to read intentions that were already being acted upon.
(Bernstein Centre for Computational Neuroscience)

It appears in Thursday's online issue of the journal Current Biology and was written by researchers from Germany, Japan and the U.K.

Participants were asked to covertly choose to either add or subtract two numbers and then hold the intention in their minds before being shown the two numbers.

By separating the task of choosing to subtract or add the numbers from the actual act of performing the calculation, the researchers were able to differentiate between the two kinds of brain activity.

A computer was then programmed to recognize characteristic patterns of activity in the brain that occur in association with specific thoughts — in this case, whether individuals were planning to add or subtract a number. Once trained, the computer was able to predict the decisions of the subjects with 70 per cent accuracy.

Regions towards the front of the brain stored the intention, whereas regions farther back took over when subjects become active and started performing the calculation, confirming previous theories, said John-Dylan Haynes from the Max Planck Institute for Human Cognitive and Brain Sciences who is one of the authors of the study.

'Intentions not encoded,' study author

Although research has been conducted to analyze the brain's activity while performing actions, Haynes said this is the first study to try to determine intentions.

"The experiments show that intentions are not encoded in single neurons but in a whole spatial pattern of brain activity," said Haynes. "Intentions for future actions that are encoded in one part of the brain need to be copied to a different region to be executed."

The technology brings to mind the futuristic world of Minority Report, the Steven Speilberg film based on the Philip K. Dick short story in which criminals are arrested before they commit crimes.

Its potential use also raises a host of privacy concerns. Haynes told the U.K.-based New Scientist magazine that the use of the technology in crime prevention is contentious and should be debated.

But he also said the technology raises hope for clinical applications. It could be used in conjunction with computer-assisted prosthetic devices, for example, to assist paralyzed patients.