Lost your keys? Your cat? The brain can rapidly mobilize a search party

April 21, 2013 by Yasmin Anwar, University of California - Berkeley
brain

A contact lens on the bathroom floor, an escaped hamster in the backyard, a car key in a bed of gravel: How are we able to focus so sharply to find that proverbial needle in a haystack? Scientists at the University of California, Berkeley, have discovered that when we embark on a targeted search, various visual and non-visual regions of the brain mobilize to track down a person, animal or thing.

That means that if we're looking for a youngster lost in a crowd, the usually dedicated to recognizing other objects, or even the areas attuned to abstract thought, shift their focus and join the search party. Thus, the brain rapidly switches into a highly focused child-finder, and redirects resources it uses for other .

"Our results show that our brains are much more dynamic than previously thought, rapidly reallocating resources based on behavioral demands, and optimizing our performance by increasing the precision with which we can perform relevant tasks," said Tolga Cukur, a postdoctoral researcher in neuroscience at UC Berkeley and lead author of the study to be published Sunday, April 21, in the journal Nature Neuroscience.

"As you plan your day at work, for example, more of the brain is devoted to processing time, tasks, goals and rewards, and as you search for your cat, more of the brain becomes involved in recognition of animals," he added.

Lost your keys? Your cat? The brain can rapidly mobilize a search party
When searching for a human, more parts of the brain are engaged (represented by the color green in the top image). The red color in the bottom image represents the brain’s attention shifting in a search for vehicles.

The findings help explain why we find it difficult to concentrate on more than one task at a time. The results also shed light on how people are able to shift their attention to challenging tasks, and may provide greater insight into neurobehavioral and attention deficit disorders such as ADHD.

These results were obtained in studies that used (fMRI) to record the of study participants as they searched for people or vehicles in movie clips. In one experiment, participants held down a button whenever a person appeared in the movie. In another, they did the same with vehicles.

The brain scans simultaneously measured neural activity via blood flow in thousands of locations across the brain. Researchers used regularized linear regression analysis, which finds correlations in data, to build models showing how each of the roughly 50,000 locations near the cortex responded to each of the 935 categories of objects and actions seen in the movie clips. Next, they compared how much of the cortex was devoted to detecting humans or vehicles depending on whether or not each of those categories was the search target.

They found that when participants searched for humans, relatively more of the cortex was devoted to humans, and when they searched for vehicles, more of the cortex was devoted to vehicles. For example, areas that were normally involved in recognizing specific visual categories such as plants or buildings switched to become tuned to humans or vehicles, vastly expanding the area of the brain engaged in the search.

"These changes occur across many brain regions, not only those devoted to vision. In fact, the largest changes are seen in the prefrontal cortex, which is usually thought to be involved in abstract thought, long-term planning and other complex mental tasks," Cukur said.

The findings build on an earlier UC Berkeley brain imaging study that showed how the brain organizes thousands of animate and inanimate objects into what researchers call a "continuous semantic space." Those findings challenged previous assumptions that every visual category is represented in a separate region of visual cortex. Instead, researchers found that categories are actually represented in highly organized, continuous maps.

The latest study goes further to show how the brain's semantic space is warped during visual search, depending on the search target. Researchers have posted their results in an interactive, online viewer. Other co-authors of the study are UC Berkeley neuroscientists Jack Gallant, Alexander Huth and Shinji Nishimoto.

Explore further: Study reveals how the brain categorizes thousands of objects and actions

More information: Attention during natural vision warps semantic representation across the human brain, DOI: 10.1038/nn.3381

Related Stories

Study reveals how the brain categorizes thousands of objects and actions

December 19, 2012
Humans perceive numerous categories of objects and actions, but where are these categories represented spatially in the brain?

Visual working memory not as specialized in the brain as visual encoding, study finds

February 6, 2012
Researchers have long known that specific parts of the brain activate when people view particular images. For example, a region called the fusiform face area turns on when the eyes glance at faces, and another region called ...

Learning to control brain activity improves visual sensitivity

December 4, 2012
Training human volunteers to control their own brain activity in precise areas of the brain can enhance fundamental aspects of their visual sensitivity, according to a new study. This non-invasive 'neurofeedback' approach ...

Brain imaging reveals the movies in our mind

September 22, 2011
Imagine tapping into the mind of a coma patient, or watching one's own dream on YouTube. With a cutting-edge blend of brain imaging and computer simulation, scientists at the University of California, Berkeley, are bringing ...

Neural balls and strikes: Where categories live in the brain

January 15, 2012
Hundreds of times during a baseball game, the home plate umpire must instantaneously categorize a fast-moving pitch as a ball or a strike. In new research from the University of Chicago, scientists have pinpointed an area ...

Recommended for you

Brain zaps may help curb tics of Tourette syndrome

January 16, 2018
Electric zaps can help rewire the brains of Tourette syndrome patients, effectively reducing their uncontrollable vocal and motor tics, a new study shows.

A 'touching sight': How babies' brains process touch builds foundations for learning

January 16, 2018
Touch is the first of the five senses to develop, yet scientists know far less about the baby's brain response to touch than to, say, the sight of mom's face, or the sound of her voice.

Researchers identify protein involved in cocaine addiction

January 16, 2018
Mount Sinai researchers have identified a protein produced by the immune system—granulocyte-colony stimulating factor (G-CSF)—that could be responsible for the development of cocaine addiction.

New study reveals why some people are more creative than others

January 16, 2018
Creativity is often defined as the ability to come up with new and useful ideas. Like intelligence, it can be considered a trait that everyone – not just creative "geniuses" like Picasso and Steve Jobs – possesses in ...

Neuroscientists suggest a model for how we gain volitional control of what we hold in our minds

January 16, 2018
Working memory is a sort of "mental sketchpad" that allows you to accomplish everyday tasks such as calling in your hungry family's takeout order and finding the bathroom you were just told "will be the third door on the ...

Brain imaging predicts language learning in deaf children

January 15, 2018
In a new international collaborative study between The Chinese University of Hong Kong and Ann & Robert H. Lurie Children's Hospital of Chicago, researchers created a machine learning algorithm that uses brain scans to predict ...

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

beleg
1 / 5 (1) Apr 21, 2013
You need space so that any meaning coupled with thought has location. Location either in the broadest sense or any sense.
In the example of broad senses of location are 'places' in 'time' like childhood.
beleg
1 / 5 (1) Apr 21, 2013
http://medicalxpr...tal.html
"...the brain organizes thousands of animate and inanimate objects into what researchers call a "continuous semantic space."

The link illustrates this.

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.