At any rate, the art or science of capturing an image from brainwave activity took an important step forward thanks to new research from the University of California, Berkeley.  Researchers at U of C used functional magnetic resonance imaging (fMRI) to peek at a subject's brain activity and attempt to read their thoughts.

A previous study had looked at using fMRI scans of parts of the brain linked to shape identification to correctly guess the a viewed image from a series of stock images.  Jack Gallant, a University of California, Berkeley neuroscientist who led the current effort, describes this previous work as similar to "the magician's card trick where you pick a card from a deck, and he guesses which card you picked. The magician knows all the cards you could have seen."

The new study expands this approach greatly by also scanning parts of the brain used for general classifications like "person", "car", or "building".  Utilizing Bayesian probabilistic math, researchers armed with a database of over 6 million possible results and the new scans were able to go beyond identification into the realm of reconstruction, coming up with an image corresponding to what the person was thinking of, after an initial calibration to adjust for mental differences.

Describes Professor Gallant, "[In the new study] the card could be a photograph of anything in the universe. The magician has to figure it out without ever seeing it."

The new study is reported in the journal Neuron and was coauthored by Berkeley postdoctoral researcher Thomas Naselaris.

With the current study researchers can get a general idea of what the person is thinking about, but lack the ability to literally draw a picture-perfect scene of the what the subject is visualizing.  This is because imaging techniques such as fMRI lump millions of neurons into single output blocks.  Frank Tong, a Vanderbilt University neuroscientist who evaluated the study describes, "At the finer level, there is a ton of information. We just don't have a way to tap into that without opening the skull and accessing it directly."

Supplementary scanning techniques, though, like optical laser scans or EEG readings could help improve the fidelity of the current information.  Professor Gallant states, "[In a few decades] you could use algorithms like this to decode other things than vision.  In theory, you could analyze internal speech. You could have someone talk to themselves, and have it come out in a machine." (Such devices currently exist, but not by tapping brainwaves... they tap neurons going to the voicebox)

Such thoughts certainly are not without alarming privacy and safety implications.  Still, such issues have seldom been able to hold back the progress of science and it looks like for better or worse, we're heading towards being able to read each others' minds, given the proper (expensive) tools.