by Marcelo Gleiser

Can we ever accomplish that age-old sci-fi dream of having a machine record your thoughts and make them available for viewing? Imagine watching your dreams played back to you so that you can try to make sense of what they are trying to tell you. (If they are trying to tell you anything.) What if someone else watches them? Or imagine having a coma patient's mind imagery revealed? The medical possibilities are endless, and so are issues of privacy and ethics.

Assuming we will be able to record someone's inner thoughts and dreams, where do we draw the line between what can and can't be revealed? Should prisoners be subjected to brain scans so that the jury can actually "see" what's in their minds? Will a jury even be required in this case? How can we differentiate between voluntary and involuntary thought and imagery? Can someone fake innocence while being guilty or vice versa?

 

Well, we are far from actually seeing inside our minds. But not as far as we used to be. A recent experiment recorded functional MRI (fMRI) data from volunteers while they were watching video clips. From their brain activity, computers were able to partially reconstruct some of the images that the volunteers saw. That is, from the information gathered by the brain scans it was possible, to a certain extent, to watch what they were watching. This is not the same as watching what was "in their minds," so to speak, but watching what their minds were watching. Still, quite an amazing achievement.

As Jack Gallant, a neuroscientist from UC Berkeley and one of the study's co-authors said, "This is a major leap toward reconstructing internal imagery ... we are opening a window into the movies in our minds."

There are many potential benefits to this technology, including futuristic brain-machine interfaces where people, healthy or otherwise, could guide computers with their minds.

But such applications are still far away. The current results took hours of consecutive brain scanning while the volunteers watched two Hollywood movie trailers. The fMRI data was gathered from the blood flow through the visual cortex, the region where vision is processed in the brain. On the computer, the brain was divided into small cubes, called voxels (volumetric pixels). As information from watching the clips arrived at the cortex and was measured by the fMRI, the computer registered what neuronal activity corresponded to what image, making a second-by-second map.

Then, the computer compared what was recorded with 18 million random video clips from YouTube, searching for matching patterns. Finally, the 100 clips that were most similar to the recorded images were merged to produce a blurry reconstruction of the original movie.

YouTube

Granted, there is still a long way to go before scientists are able to see inside your mind. Two obvious challenges are the slowness of fMRI data gathering as compared to the speed of neuronal information processing and the limited size of the video library used for comparison. (For example, there was no video of an elephant, making that portion of the match problematic, as you can see.) However, as with so many new technologies, while the first breakthrough steps are small, progress happens much faster than predicted.

We may not need to worry about how to censor our dreams from our spouses, but our children probably will.

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