Study offers new clue on how brain processes visual information, provides insight into neural mechanisms of attention

July 23, 2012
brain

Ever wonder how the human brain, which is constantly bombarded with millions of pieces of visual information, can filter out what's unimportant and focus on what's most useful?

The process is known as selective attention and scientists have long debated how it works. But now, researchers at Wake Forest Baptist Medical Center have discovered an important . Evidence from an , published in the July 22 online edition of the journal Nature Neuroscience, shows that the is involved in a previously unknown way.

Two types of attention are utilized in the selective attention process – bottom up and top down. Bottom-up attention is automatically guided to images that stand out from a background by virtue of color, shape or motion, such as a billboard on a highway. Top-down attention occurs when one's focus is consciously shifted to look for a known target in a visual scene, as when searching for a relative in a crowd.

Traditionally, scientists have believed that separate areas of the brain controlled these two processes, with bottom-up attention occurring in the posterior parietal cortex and top-down attention occurring in the prefrontal cortex.

"Our findings provide insights on the neural mechanisms behind the guidance of attention," said Christos Constantinidis, Ph.D., associate professor of neurobiology and anatomy at Wake Forest Baptist and senior author of the study. "This has implications for conditions such as attention deficit hyperactivity disorder (ADHD), which affects millions of people worldwide. People with ADHD have difficulty filtering information and focusing attention. Our findings suggest that both the ability to focus attention intentionally and shifting attention to eye-catching but sometimes unimportant stimuli depend on the prefrontal cortex."

In the Wake Forest Baptist study, two monkeys were trained to detect images on a computer screen while activity in both areas of the brain was recorded. The visual display was designed to let one image "pop out" due to its color difference from the background, such as a red circle surrounded by green. To trigger bottom-up attention, neither the identity nor the location of the pop-out image could be predicted before it appeared. The monkeys indicated that they detected the pop-out image by pushing a lever.

The neural activity associated with identifying the pop-out images occurred in the prefrontal cortex at the same time as in the posterior parietal cortex. This unexpected finding indicates early involvement of the prefrontal cortex in bottom-up attention, in addition to its known role in top-down attention, and provides new insights into the of attention.

"We hope that our findings will guide future work targeting deficits," Constantinidis said.

Explore further: Researchers gain new insight into prefrontal cortex activity

Related Stories

Researchers gain new insight into prefrontal cortex activity

March 5, 2012
The brain has a remarkable ability to learn new cognitive tasks while maintaining previously acquired knowledge about various functions necessary for everyday life. But exactly how new information is incorporated into brain ...

Regulation of attention and concentration in brain unravelled

August 11, 2011
(Medical Xpress) -- The prefrontal cortex of the brain is involved in memory processes and the ability to concentrate attentively. Neuroscientists from VU University Amsterdam have shown how and where this occurs in the prefrontal ...

Human attention to a particular portion of an image alters the way the brain processes visual cortex responses to that i

March 30, 2012
Our ability to ignore some, but not other stimuli, allows us to focus our attention and improve our performance on a specific task. The ability to respond to visual stimuli during a visual task hinges on altered brain processing ...

Attention and awareness uncoupled in brain imaging experiments

November 10, 2011
In everyday life, attention and awareness appear tightly interwoven. Attending to the scissors on the right side of your desk, you become aware of their attributes, for example the red handles. Vice versa, the red handles ...

Recommended for you

Researchers find monkey brain structure that decides if viewed objects are new or unidentified

August 18, 2017
A team of researchers working at the University of Tokyo School of Medicine has found what they believe is the part of the monkey brain that decides if something that is being viewed is recognizable. In their paper published ...

Artificial neural networks decode brain activity during performed and imagined movements

August 18, 2017
Artificial intelligence has far outpaced human intelligence in certain tasks. Several groups from the Freiburg excellence cluster BrainLinks-BrainTools led by neuroscientist private lecturer Dr. Tonio Ball are showing how ...

How whip-like cell appendages promote bodily fluid flow

August 18, 2017
Researchers at Nagoya University have identified a molecule that enables cell appendages called cilia to beat in a coordinated way to drive the flow of fluid around the brain; this prevents the accumulation of this fluid, ...

Study of nervous system cells can help to understand degenerative diseases

August 18, 2017
The results of a new study show that many of the genes expressed by microglia differ between humans and mice, which are frequently used as animal models in research on Alzheimer's disease and other neurodegenerative disorders.

Researchers make surprising discovery about how neurons talk to each other

August 17, 2017
Researchers at the University of Pittsburgh have uncovered the mechanism by which neurons keep up with the demands of repeatedly sending signals to other neurons. The new findings, made in fruit flies and mice, challenge ...

Neurons involved in learning, memory preservation less stable, more flexible than once thought

August 17, 2017
The human brain has a region of cells responsible for linking sensory cues to actions and behaviors and cataloging the link as a memory. Cells that form these links have been deemed highly stable and fixed.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.