Neuroscientists unlock shared brain codes

October 20, 2011

A team of neuroscientists at Dartmouth College has shown that different individuals' brains use the same, common neural code to recognize complex visual images.

The paper, "A common, high-dimensional model of the neural representational space in human ventral temporal ," is in the October 20, 2011, issue of the journal, Neuron. The lead author of the paper is James Haxby, the Evans Family Distinguished Professor of in the Department of Psychological and . Haxby is also the Director of the Cognitive Neuroscience Center at Dartmouth and a professor in the Center for Mind/Brain Sciences at the University of Trento in Italy. Swaroop Guntupalli, a graduate student in Haxby's laboratory, developed the software for the new methods and ran the tests of their validity.

Haxby developed a new method called hyperalignment to create this common code and the parameters that transform an individual's patterns into the code.

The parameters are a set of numbers that act like a combination that unlocks that individual's brain's code, Haxby said, allowing activity patterns in that person's brain to be decoded – specifying the that evoked those patterns -- by comparing them to patterns in other people's brains.

"For example, patterns of brain activity evoked by viewing a movie can be decoded to identify precisely which part of the movie an individual was watching by comparing his or her brain activity to the brain activity of other people watching the same movie," said Haxby.

When someone looks at the world, visual images are encoded into patterns of brain activity that capture all of the subtleties that make it possible to recognize an unlimited variety of objects, animals, and actions.

"Although the goal of this work was to find the common code, these methods can now be used to see how brain codes vary across individuals because of differences in visual experience due to training, such as that for air traffic controllers or radiologists, to cultural background, or to factors such as genetics and clinical disorders," he said.

Because of variability in brain anatomy, brain decoding had required separate analysis of each individual. Although detailed analysis of an individual could break that person's brain code, it didn't say anything about the brain code for a different person. In the paper, Haxby shows that all individuals use a common code for visual recognition, making it possible to identify specific patterns of brain activity for a wide range of visual images that are the same in all brains.

As a result of their research, the team showed that a pattern of brain activity in one individual can be decoded by finding the picture or movie that evoked the same pattern in other individuals.

Participants in the study watched the movie Raiders of the Lost Ark while their patterns of brain activity were measured using fMRI. In two separate experiments, they viewed still images of seven categories of faces and objects – male and female human faces, monkey faces, dog faces, shoes, chairs and houses – or six animal species – squirrel monkeys, ring-tailed lemurs, mallards, yellow-throated warblers, ladybugs and luna moths. Analysis of the brain evoked by the movie produced the common code. Once the patterns were in the common code, including responses that were not evoked by the movie, distinct patterns were detected that were common across individuals and specific for fine distinctions, such as monkey versus dog faces, squirrel monkeys versus lemurs.

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10 comments

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hush1
2 / 5 (5) Oct 20, 2011
Code? Then dynamic.
At most, pliable hard-wiring rewiring at the rate of input from external stimuli delivered by the senses.

...that evoked the same pattern in other individuals.

Same pattern? Where? Same region, at the most.

People hearing sound when viewing motion?
People when touched hearing sound?

Decoded?
Not even wrong.
Pirouette
1 / 5 (2) Oct 20, 2011
lol Hush1. . .I immediately thought of you after reading this article, and then. . .here you are.
It's not my forte, so I will not comment further.
maxcypher
4 / 5 (1) Oct 20, 2011
Patterns of Persistence
hush1
not rated yet Oct 20, 2011
Supplement to persistence:
http://www.jstor..../1421464

In ancient times (1976) researchers conjunctured the following, here a partial abstract:

"The interpretation is that visual persistence is an active, continuously operating process rather than a passive neural copy of the stimulus."
Isaacsname
not rated yet Oct 21, 2011
What about people that experience extreme sensory stochastic resonance ?
hush1
not rated yet Oct 26, 2011
Well, kudos, Isaacsname. Astute.
Extreme? The descriptor makes no sense.

Sensory stochastic resonance appears universal - all life(all cells).

Physically, noise IS a state that is universal.

QM and gravity 'detectives' in search of gravity waves and superpositions and/or entanglements will go the ANY length to avoid noise.

Because the word "extreme" makes no sense to me in the context of sensory stochastic resonance, I can not tell what point you are making with that descriptor.

What do you mean by "extreme?" (How much is extreme?)
What do you mean by "experience?" (What event represent experience?)
What do you mean by "people?" (Who has this?)

There is saturation point, sensory adaptation...
http://www.mitpre...9.5.1047

I recommend this literature. In light of the fact that I almost never recommend literature. Yes, 1997 - almost modern.

Your thoughts are of more value, when readers don't have to guess the point you are making.

hush1
not rated yet Oct 26, 2011
Hyperalignment does not produce code. Much less common code representing all things physical experienced.

Hyperalignment is hype. A lot of noise. Much ado about nothing.
hush1
not rated yet Oct 26, 2011
Hyperalignment.
Not even wrong.
hush1
not rated yet Oct 26, 2011
Neuroscientists unlock shared nonsense.

There. Much better.
kaasinees
not rated yet Oct 26, 2011
is this related to?

http://www.scienc...3719.htm

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