Your private thoughts could be used to pry information out of somebody else's mind. Today a group of neuroscientists announced they used test subjects' brains to train computers how to "recognize" electrical patterns created by thoughts. Specifically, they trained the computers to recognize thoughts about objects such as hammers and drills. You can imagine how this would come in handy during interrogations: Just stick a person in an MRI and scan her brain for telltale patterns while you ask her what kinds of weapons the bad guys have. So, how did the researchers do it?

Scientists conducted an experiment where they asked people in an MRI brain scanner to look at ten pictures of different tools and houses. Meanwhile, the researchers fed the data into a computer algorithm so that the program would learn to recognize the unique signature of electrical patterns produced by the objects in each subject's brain. Eventually the algorithm began to "recognize" thought signatures associated with the objects. The surprise was that people's thought patterns related to each object were quite similar.

Tom Mitchell, a neuroscientist and computer scientist at Carnegie Mellon who worked on the study, said:


There has always been a philosophical conundrum as to whether one person's perception of the color blue is the same as another person's. Now we see that there is a great deal of commonality across different people's brain activity corresponding to familiar tools and dwellings.

Mitchell's co-author Svetlana Shinkareva at University of South Carolina added alarmingly:
We hope to progress to identifying the thoughts associated not just with pictures, but also with words, and eventually sentences.
Remember what I was saying about interrogation? Yeah. Let's hope they don't go there.

Using fMRI Brain Activation to Identify Cognitive States Associated with Perception of Tools and Dwellings [PLoS One]