MovieChat Forums > Bis ans Ende der Welt (1991) Discussion > spooky

spooky

posted 16 years ago by Gary_Allen
1 reply | jump to latest

Mind-reading machine knows what the eye can see
18:11 05 March 2008
NewScientist.com news service
James Urquhart
Web LinksUniversity of California, Berkeley
John-Dylan Haynes, Max Planck Institute
Functional magnetic resonance imaging, Wikipedia
A device that reveals what a person sees by decoding their brain activity could soon be a reality, say researchers who have developed a more sophisticated way to extract visual stimuli from brain signals.
Scientists at the University of California, Berkeley, US, developed a computational model that uses functional MRI (fMRI) data to decode information from an individual's visual cortex – the part of the brain responsible for processing visual stimuli.
"Our research makes substantial advances towards being able to decode mental content from brain activity as measured using fMRI," Kendrick Kay, a co-author of the study, told New Scientist. "In fact, our results suggest it may soon be possible to reconstruct our visual experiences from brain activity."
Complex imagesPrevious research has shown that fMRI can pick out brain activity associated with viewing different images. But so far it has only been possible to identify very basic images, from fixed categories, such as a face or a house. The process also depends on prior knowledge of the associated brain activity.
Now the Berkeley team has shown that brain imaging can reveal much more complex and arbitrary images, without prior knowledge of brain activity.
The team first used fMRI to measure visual cortex activity in people looking at more than a thousand photographs. This allowed them to develop a computational model and "train" their decoder to understand how each person's visual cortex processes information.
Next, participants were shown a random set of just over 100 previously unseen photographs. Based on patterns identified in the first set of fMRIs, the team was able to accurately predict which image was being observed.
Dream reader?"It is going to be particularly powerful in the field of visual perception and possibly the field of decoding motor responses," says John-Dylan Haynes of the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany.
The research also hints that scientists might one day be able to access dreams, memories and imagery, says Haynes, providing the brain processes dreams in a way that is analogous to visual stimuli.
"The difficulty is that that it's very hard to set up models for other types of complex thoughts, such as memories and intentions," Haynes says.
Journal reference: Nature (DOI: 10.1038/nature06713)

[–] Gary_Allen 15 years ago

http://www.cnn.com/2009/TECH/09/25/brain.scans.wired/index.html

Brain scans reveal what you've seen
Researchers are trying to extract the images people see in their brains

Using fMRI machines, researchers try to guess what's in someone's head

Scientist: Tech could be used "to build a functional brain-reading device"

Such brain communication likely will not be available for decades
updated 9:45 a.m. EDT, Fri September 25, 2009

By Brandon Keim

(WIRED) -- Scientists are one step closer to knowing what you've seen by reading your mind.

Researchers used fMRI technology to try to pull images out of peoples' brains.

Having modeled how images are represented in the brain, the researchers translated recorded patterns of neural activity into pictures of what test subjects had seen.

Though practical applications are decades away, the research could someday lead to dream-readers and thought-controlled computers.

"It's what you would actually use if you were going to build a functional brain-reading device," said Jack Gallant, a University of California, Berkeley neuroscientist.

The research, led by Gallant and Berkeley postdoctoral researcher Thomas Naselaris, builds on earlier work in which they used neural patterns to identify pictures from within a limited set of options.

The current approach, described this week in Neuron, uses a more complete view of the brain's visual centers. Its results are closer to reconstruction than identification, which Gallant likened 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."

In the latest study, "the card could be a photograph of anything in the universe. The magician has to figure it out without ever seeing it," said Gallant.

To construct their model, the researchers used an fMRI machine, which measures blood flow through the brain, to track neural activity in three people as they looked at pictures of everyday settings and objects.

As in the earlier study, they looked at parts of the brain linked to the shape of objects. Unlike before, they looked at regions whose activity correlates with general classifications, such as "buildings" or "small groups of people."

Once the model was calibrated, the test subjects looked at another set of pictures. After interpreting the resulting neural patterns, the researchers' program plucked corresponding pictures from a database of 6 million images.

Frank Tong, a Vanderbilt University neuroscientist who studies how thoughts are manifested in the brain, said the Neuron study wasn't quite a pure, draw-from-scratch reconstruction. But it was impressive nonetheless, especially for the detail it gathered from measurements that are still extremely coarse.

The researchers' fMRI readings bundled the output of millions of neurons into single output blocks. "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," said Tong.

Gallant hopes to develop methods of interpreting other types of brain activity measurement, such as optical laser scans or EEG readings.

He mentioned medical communication devices as a possible application, and computer programs for which visual thinking makes sense -- CAD-CAM or Photoshop, straight from the brain.

Such applications are decades away, but "you could use algorithms like this to decode other things than vision," said Gallant. "In theory, you could analyze internal speech. You could have someone talk to themselves, and have it come out in a machine."