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

July 23, 2012, Wake Forest University Baptist Medical Center
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

Research reveals atomic-level changes in ALS-linked protein

January 18, 2018
For the first time, researchers have described atom-by-atom changes in a family of proteins linked to amyotrophic lateral sclerosis (ALS), a group of brain disorders known as frontotemporal dementia and degenerative diseases ...

Fragile X finding shows normal neurons that interact poorly

January 18, 2018
Neurons in mice afflicted with the genetic defect that causes Fragile X syndrome (FXS) appear similar to those in healthy mice, but these neurons fail to interact normally, resulting in the long-known cognitive impairments, ...

How your brain remembers what you had for dinner last night

January 17, 2018
Confirming earlier computational models, researchers at University of California San Diego and UC San Diego School of Medicine, with colleagues in Arizona and Louisiana, report that episodic memories are encoded in the hippocampus ...

Recording a thought's fleeting trip through the brain

January 17, 2018
University of California, Berkeley neuroscientists have tracked the progress of a thought through the brain, showing clearly how the prefrontal cortex at the front of the brain coordinates activity to help us act in response ...

Midbrain 'start neurons' control whether we walk or run

January 17, 2018
Locomotion comprises the most fundamental movements we perform. It is a complex sequence from initiating the first step, to stopping when we reach our goal. At the same time, locomotion is executed at different speeds to ...

Miles Davis is not Mozart: The brains of jazz and classical pianists work differently

January 16, 2018
Keith Jarret, world-famous jazz pianist, once answered in an interview when asked if he would ever be interested in doing a concert where he would play both jazz and classical music: "No, that's hilarious. [...] It's like ...

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.