Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Attention acts as visual glue

02.08.2002


When you gaze at a bowl of fruit, why don’t some of the bananas look red, some of the apples look purple and some of the grapes look yellow?

This question isn’t as nonsensical as it may sound. When your brain processes the information coming from your eyes, it stores the information about an object’s shape in one place and information about its color in another. So it’s something of a miracle that the shapes and colors of each fruit are combined seamlessly into distinct objects when you look at them.

Exactly how the brain recombines these different types of visual information after it has broken them apart is called the "binding problem" and is currently the subject of considerable controversy in the neuroscience community. But the results of a brain mapping experiment, published online by the Proceedings of the National Academy of Sciences on July 29, provide significant new support for the theory that attention is the glue that cements visual information together as people scan complex visual scenes.



The study was a collaboration among René Marois, assistant professor of psychology at Vanderbilt; John C. Gore, who recently moved from Yale to become a Chancellor’s University Professor at Vanderbilt; and Yale graduate student Keith M. Shafritz.

"There are more than a dozen places in the brain involved with processing visual information, each specializing in information with slightly different attributes," says Marois. "Some specialize in processing color, some specialize in processing shape, while others specialize in movement. These areas are not clustered together, but distributed widely around the back of the brain."

There are two leading theories about how the brain reintegrates this information.

One view proposes that the neurons in the scattered areas are bound together in a way that allows them to act simultaneously. When you look at a banana, the neurons that store information about the banana’s shape fire simultaneously with the neurons in a different region of the brain that store information about the banana’s color. It is the direct functional interaction between neurons located in different visual areas that binds together an object’s numerous visual properties.

In the 1980’s, Anne M. Triesman at Princeton and her colleagues advanced an alternative mechanism. She proposed that visual binding is mediated by the parietal cortex, an area of the brain known to be involved in spatial attention. She suggested that the act of focusing one’s attention on an object’s spatial location provides the key that binds the different types of visual information together. If an apple is sitting on the table in front of a woman, then her brain, specifically the parietal cortex, associates the information about its color and shape with its location and uses the spatial information to bind together the visual information whenever she focuses her attention on the apple.

The description of a patient who, following a brain injury in the parietal lobe, had difficulty associating colors with more than one object at a time gave Marois the idea for the basic experiment. When the person was presented with objects one at a time, he had no problem properly pairing their shapes and colors. When presented with two or more objects at the same time, however, he often mismatched the color of one object with the shape of another.

So Marois designed a series of trials that asked subjects to concentrate on the shape only, the color only or both shape and color of pairs of objects displayed on a computer screen while their brain activity was monitored using the technique called functional MRI. The researchers presented these pairs to the individuals either sequentially in the same location or simultaneously at different locations and recorded the areas in the brain that were most active.

"The purpose of our study was really to test the attention theory as strongly as we could," says Marois. "I was actually surprised that it worked because we had to adopt such stringent testing conditions."

Despite their stringency, the tests showed that activity in the parietal region increased significantly whenever the individuals were presented with more than one object at the same time.

"This provides strong evidence in favor of the theory that spatial attention is the binding glue that the brain uses to integrate visual objects whenever it is presented with more than one object at the same time, which is most of the time," says Marois.

While the study results support the attention theory, they do not rule out other mechanisms. "In fact," he adds, "it is practically certain that the brain uses several mechanisms to solve this fascinating problem."


The project was funded by a grant from the National Institute of Neurological Disorders and Stroke.

For more news about research at Vanderbilt, visit Exploration, Vanderbilt’s online research magazine at http://exploration.vanderbilt.edu.


David F. Salisbury | EurekAlert!
Further information:
http://exploration.vanderbilt.edu
http://www.vanderbilt.edu/

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>