NOT TO WORRY: Researchers demonstrate an algorithm than can indentify images by translating brain activity—still a far cry from reading minds.
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File this under futuristic (and perhaps a little scary): In a step toward one day perhaps deciphering visions and dreams, new research unveils an algorithm that can translate the activity in the minds of humans.
Scientists from the University of California, Berkeley, report in Nature today that they have developed a method capable of decoding the patterns in visual areas of the brain to determine what someone has seen. Needless to say, the potential implications for society are sweeping.
"This general visual decoder would have great scientific and practical use," the researchers say. "We could use the decoder to investigate differences in perception across people, to study covert mental processes such as attention, and perhaps even to access the visual content of purely mental phenomena such as dreams and imagery."
The scientists say that previous attempts to extract "mental content from brain activity" only allowed them to decode a finite number of patterns. Researchers would feed image to an individual (or ask them to think about an object) one at a time and then look for a corresponding brain activity pattern. "You would need to know [beforehand], for each thought you want to read out, what kind of pattern of activity goes with it," says John-Dylan Haynes, a professor at the Bernstein Center for Computational Neuroscience Berlin and the Max Planck Institute for Human Cognitive and Brain Sciences that was not affiliated with the new work.
"The advance brought forward here," he continues, "is that they have set up a mathematical model that captures the properties of the visual part of the brain," which can then be applied to previously unseen objects.
Researchers used functional magnetic resonance images (fMRIs) to record activity in the visual cortices of a pair of volunteers (two of the study's co-authors) while they viewed a series of images. They examined the brain by dividing the regions into voxels (volumetric units, or 3-D pixels) and noting the part of the picture to which each section responded. For instance, one voxel, or slice, might respond in a certain pattern to, say, colors in the upper left-hand corner of the photo, whereas another voxel would be set off by something in a different portion of the picture.
Haynes says the team could "go back and infer what the image was that a person was seeing" by monitoring the activity in each brain section and deciphering what sort of information would most likely be found in the corresponding part of the visual field, or photograph.
When the volunteers scanned a new set of 120 images—depicting everything from people to houses to animals to fruit and other objects—the computer program correctly identified what they were looking at up to 92 percent of the time; when the image pool was upped to 1,000, the algorithm was successful 80 percent of the time. Naturally, its accuracy decreased as the number of possible pictures grew, but even at a quantity 100 times greater than the number of images indexed on the Internet by Google, according to the scientists, the model would be successful greater than 10 percent of the time. (This far exceeds the success rate of random guessing.)
"This indicates," the researchers wrote, "that fMRI signals contain a considerable amount of stimulus information and that this information can be successfully decoded in practice."
Haynes says the method is limited to deciphering information that can be mapped out in space, such as sensory inputs (where a sound is coming from) or motor function (what action one's arm has performed). The challenge, he says, is that it cannot "be easily applied to cases where you don't have a clear mathematical model," such as memories, intentions and emotions. "High-level thoughts would be a bit tricky to get a hold of without such a mathematical model," he adds.
So, you can keep that tinfoil helmet in your closet for now. These algorithms still can't read our innermost thoughts—at least not yet.
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7 Comments
Add CommentI have written a screenplay titled "2020-TGA" which is a break-thru technology in the year 2020 that allows access to thought energies. In other words it allows a "reading of the mind". If thoughts are "things", at some point in the future this is predictable. Contact me for more info: vincewms@earthlink.net
Reply | Report Abuse | Link to thisThat our minds are fully instantiated by our physical brains is news to no one who does not subscribe to absurd dualistic, supernatural notions of a conscious self, apart from the natural world... or an ethereal "free willing" soul beyond the causal boundries of biochemistry.
Reply | Report Abuse | Link to thisIt was only a matter of time until a computational model emerged from fMRI patterns in these highly controlled studies that rather crudely represented portions of our visual cortices. Kudos to the researchers for this apparently effective "first pass" at a model that certainly will be refined and expanded... but wholly dependent of the specificity of the input received.
Inter-subjective differences will be interesting when the same stimuli are offered and should help explain our inate, "hard-wired" processing biases.
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Edited by Spin-oza at 03/09/2008 7:23 PM
Probably 'Spin-oza' is correct in his/her claim that [i][b]"our minds are fully instantiated by our physical brains".[/b][/i] There is considerable evidence pointing that way.
Reply | Report Abuse | Link to thisHowever, until the case is fully made, it may be wiser to think in terms of the[i][b] 'brain-mind complex'[/b][/i] as the entity responsible for our thoughts, 'mind' being something 'associated' with the 'brain'. The nature of the association is still not clear and there is, I believe, a lot of work to be done to make the needed scientific clarifications.
Science and scientists should not fall into the 'religionist' trap of believing (now or ever) that they have [i][b]ALL[/b][/i] the answers.
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Edited by gs_chandy at 03/06/2008 9:58 PM
Typical overhyped result.
Reply | Report Abuse | Link to thisThe researchers can basically look at brainwave patterns and guess with 80% accuracy which picture from a library of photos the subject looked at. As long as you don't have too many subjects. And as long as you don't have too many pictures. And the pictures aren't too complicated.
What they have really done is made a slight progress in determining how the electrical signals from the optic nerve wind up in the brain.
To GS_CHANDY
Reply | Report Abuse | Link to thisWhat exactly is meant by the "mind-brain complex"? That merely attaches a layer of obscurity to an already extremely layered and deep subject... consciousness, human or otherwise.
I never even remotely suggested that "science has all the answers"... and that is a classic "strawman". NO... thankfully, as opposed to stale religious dogma, science is an evolving dialogue.
BUT like every other function of our bodies... the brain with its hundred billion neurons and trillions of connections is wholly responsible for processing that which we call "thought"... which of course is highly driven by language... and thus culture. It is interesting to remember that the vast preponderance of our thought is subconscious and only a smidgen enter our attentive frame of reference. Our GI tract has it's own "mind-body" complex... but no one seriously believes its function is based on the supernatural or ethereal as opposed to the neuromuscular-chemical-endocrine signals which have clear anatomic pathways... which was my fundamental point.
The computational model presented is "landmark" because it predicts visual content NOT previously shown. Whether the neural patterns in our physical brains are completely representational of all conscious thought and qualia... or by necessity inform "higher functions" ... which act to modulate the neural network itself, is irrelevant in my view.
Sir Francis Crick's "Astonishing Hypothesis" is still correct and there will surely be, as this report highlights, tight neural-anatomic correlates of consciousness... as has been shown here with the component of visual processing... one of the human animal's most important tasks.
CHEERS
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Edited by Spin-oza at 03/09/2008 7:55 PM
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Edited by Spin-oza at 03/10/2008 7:21 AM
on reading the nature report, I see no mention of using color images, only greyscale, were you speaking in general terms or specific to this study? just curious, thanks
Reply | Report Abuse | Link to thisempty
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Edited by fd97207 at 04/17/2008 9:37 AM