Eyes on the prize

December 24, 2008

Dollar signs for eyes - cartoonists have been drawing them for years, and the artists, while whimsical, may have been onto something. According to new research from UC San Diego, areas of the brain responsible for vision respond more strongly to objects of value.

Led by John Serences, assistant professor of psychology and head of the Perception and Cognition Lab at UC San Diego, the study is published in the Dec. 26 issue of the Cell Press journal Neuron.

Past rewards influence how humans (and other animals) make decisions. We've known about that for a long time, said Serences - through day-to-day experience as well as the numerous experiments of economists and cognitive psychologists. Though more and more research is looking into it, little is known about how rewards affect the way the brain processes incoming sensory information, specifically as it relates to vision. Could it be that we see things differently if they have paid off before?

Serences examined how value affects visual processing with functional magnetic resonance imaging (fMRI), a brain-scanning technique that indirectly measures neural activity. The brain activity of subjects was recorded as they chose between red and green targets that varied in value across the experiment. Selecting a target might yield 10 cents or nothing, potentially earning subjects making the "right" choices 10 dollars. The fMRI scans were conducted at UC Irvine.

Analysis revealed that rewards altered neural activation in many areas of the human visual system, including the very first visually responsive region of the brain, the area of the cortex known as "V1," which is associated with representing basic features such as edge orientations and color.

"When a target had been valuable in the past - if selecting it had had paid off with money- the visual system represented it more strongly," Serences said. "Rewards affected information processing not just at a high level of cognitive function but right from the get-go."

"Though it is too early to say how this relates to perception," said Serences, "it raises the intriguing possibility that we see things we value more clearly - much like the way the brain responds to a bright object versus a dimly lit one."

Interestingly, changes in neural activity were better associated with the reward history of the red/green targets than with self-reported estimates of value: "It's as if the visual system is telling you how valuable something has been to you in the past," Serences said, "and telling it to you like it is, even though you can't consciously identify it."

The study also found activation in the frontal and parietal regions of the brain previously implicated in anticipating and tracking rewards. These areas were very active when one choice was much more valuable than the other, suggesting, Serences said, that these regions may provide signals to bias visual processing and so have a greater impact on decision-making and behavior.

Further research on how the brain represents the value of different objects, Serences said, could someday help us better understand how addictions influence information processing in the brain. The mere sight of drugs or particular foods, for example, may have a larger impact on the psyches of some people. Their eyes may be on the wrong prize.
-end-


University of California - San Diego

Related Brain Articles from Brightsurf:

Glioblastoma nanomedicine crosses into brain in mice, eradicates recurring brain cancer
A new synthetic protein nanoparticle capable of slipping past the nearly impermeable blood-brain barrier in mice could deliver cancer-killing drugs directly to malignant brain tumors, new research from the University of Michigan shows.

Children with asymptomatic brain bleeds as newborns show normal brain development at age 2
A study by UNC researchers finds that neurodevelopmental scores and gray matter volumes at age two years did not differ between children who had MRI-confirmed asymptomatic subdural hemorrhages when they were neonates, compared to children with no history of subdural hemorrhage.

New model of human brain 'conversations' could inform research on brain disease, cognition
A team of Indiana University neuroscientists has built a new model of human brain networks that sheds light on how the brain functions.

Human brain size gene triggers bigger brain in monkeys
Dresden and Japanese researchers show that a human-specific gene causes a larger neocortex in the common marmoset, a non-human primate.

Unique insight into development of the human brain: Model of the early embryonic brain
Stem cell researchers from the University of Copenhagen have designed a model of an early embryonic brain.

An optical brain-to-brain interface supports information exchange for locomotion control
Chinese researchers established an optical BtBI that supports rapid information transmission for precise locomotion control, thus providing a proof-of-principle demonstration of fast BtBI for real-time behavioral control.

Transplanting human nerve cells into a mouse brain reveals how they wire into brain circuits
A team of researchers led by Pierre Vanderhaeghen and Vincent Bonin (VIB-KU Leuven, Université libre de Bruxelles and NERF) showed how human nerve cells can develop at their own pace, and form highly precise connections with the surrounding mouse brain cells.

Brain scans reveal how the human brain compensates when one hemisphere is removed
Researchers studying six adults who had one of their brain hemispheres removed during childhood to reduce epileptic seizures found that the remaining half of the brain formed unusually strong connections between different functional brain networks, which potentially help the body to function as if the brain were intact.

Alcohol byproduct contributes to brain chemistry changes in specific brain regions
Study of mouse models provides clear implications for new targets to treat alcohol use disorder and fetal alcohol syndrome.

Scientists predict the areas of the brain to stimulate transitions between different brain states
Using a computer model of the brain, Gustavo Deco, director of the Center for Brain and Cognition, and Josephine Cruzat, a member of his team, together with a group of international collaborators, have developed an innovative method published in Proceedings of the National Academy of Sciences on Sept.

Read More: Brain News and Brain Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.