Neuroscientists unlock shared brain codes

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 cortex,” 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 Cognitive Neuroscience in the Department of Psychological and Brain Sciences. 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 brain activity 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 visual images 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. …

via Neuroscientists unlock shared brain codes.

The image is not moving, by the way.

Future computers could rewire themselves

Future microchips may have only one type of component, capable of rewiring itself to do different jobs.

Researchers from Northwestern University in the US have developed a material that can radically change its electronic properties.

A resistor made from it could become a transistor or a diode, according to the report in the journal Nature Nanotechnology.

The discovery could lead to cheaper, smaller and more powerful computers.

As electronics advance and demands for portability increase, one of the main challenges has been decreasing the size of elementary components.

Technology firms have attempted to address this with a number of innovations, including new ways of building circuit tracks so signals do not suffer damaging interference at ultra small sizes.

The Northwestern University team took a different approach.

“It’s becoming more and more challenging to make devices smaller and you need to think of new ways rather than just shrinking things down because you’re reaching a fundamental scientific limit here of how small you can make a device,” said David Walker, one of the researchers.

“Our solution to this is instead of making things smaller, why don’t we try to make them more versatile – by taking all these hardware components and building them into one. …

To achieve this, the scientists have created a new material that consists of a “sea” of small negatively charged particles and larger, positively charged particles, which are “jammed” in place.

Because the negative particles form conductive regions, they act like conventional copper tracks in a circuit.

Once an electrical charge is applied to the material, those particles can be shifted around and reconfigured.

“Like redirecting a river, streams of electrons can be steered in multiple directions through a block of the material – even multiple streams flowing in opposing directions at the same time,” explained the lead researcher, Professor Bartosz Grzybowski, of Northwestern University.

This unusual property could allow a component made from this material to change its functions – allowing, in turn, a future computer to redirect and adapt its own circuitry as required.

“So the computer could send some set of electrical impulses or some type of electrical potential, and that would actually reconfigure the device to operate in a different way,” said Mr Walker. …

He explained that there was not yet a name for the new material, but it was unlike any other material that exists today. …

via BBC News – Future computers could rewire themselves.