Visual Images From Brain Activity Reconstructed By Scientists

http://pinktentacle.com/2008/12/scientists-extract-images-directly-from-brain/

Three years ago, a research from Japan’s ATR Computational Neuroscience Laboratories has developed new brain analysis technology that can reconstruct the images inside a person’s mind and display them on a computer monitor.  Scientists who were tasked to do this research were able to reconstruct various images viewed by a person using a functional magnetic resonance imaging (fMRI) machine.  During that time, the system was only able to reproduce simple black-and-white images.

A recent development to fMRI machine is now capable of reproducing images in color.  The functional magnetic resonance imaging (fMRI) studies have demonstrated brain motion produced by static visual patterns and have reconstructed these patterns from brain activity. There are simple examples of reconstruction done by the researchers, one of which is through watching movies.

The subject of this test has undergone the following process:

1. Record brain activity while the subject watches several hours of movie trailers.
2. Build dictionaries (regression model; see below) to translate between the shapes, edges and motion in the movies and measured brain activity. A separate dictionary is constructed for each of several thousand points in the brain at which brain activity was measured.  (For experts: our success here in building a movie-to-brain activity encoding model that can predicts brain activity to arbitrary novel movie inputs was one of the keys of this study)
3. Record brain activity to a new set of movie trailers that will be used to test the quality of the dictionaries and reconstructions.
4. Build a random library of ~18,000,000 seconds of video downloaded at random from YouTube (that have no overlap with the movies subjects saw in the magnet). Put each of these clips through the dictionaries to generate predictions of brain activity. Select the 100 clips whose predicted activity is most similar to the observed brain activity. Average those clips together. This is the reconstruction.

http://www.popsci.com/science/article/2011-09/mind-reading-tech-reconstructs-videos-brain-images

According to the researchers, there are also limitations in brain decoding.  Decoding performance depends on the quality of brain activity measurements.  This technology can only reconstruct movie clips people have already viewed. Reconstructing movies using brain scans has been challenging because the blood flow signals measured using fMRI change much more slowly than the neural signals that encode dynamic information in movies, researchers said. For this reason, most previous attempts to decode brain activity have focused on static images.  However, the breakthrough paves the way for reproducing the movies inside our heads that no one else sees, such as dreams and memories.  They also stressed that practical applications of the technology could include a better understanding of what goes on in the minds of people who cannot communicate verbally, such as stroke victims, coma patients and people with neurodegenerative diseases.

You can check out the details on the breakthrough here:
Mind-Reading Tech Reconstructs Videos From Brain Images
Scientists extract images directly from brain