Neuronal correlates of the set-size effect in monkey lateral intraparietal area

Jul 01, 2008

It is well known that the brain is limited in the amount of sensory information it can process at any given time. During an everyday task such as finding an object in a cluttered environment (known as visual search), observers take longer to find a target as the number of distractors increases.

This well-known phenomenon implies that inputs from distractors interfere with the brain's ability to perceive the target at some stage (or stages) of neural processing.

However, the loci and mechanisms of this interference are unknown. Visual information is processed in feature-selective areas that encode the physical properties of stimuli, and in higher-order areas that convey information about behavioral significance and help direct attention to individual stimuli.

This week in PLoS Biology, Jacqueline Gottlieb and colleagues show how a higher-order parietal area relates to attention and eye movements. They found that parietal neurons selectively track the location of a search target during a difficult visual search task.

However, parietal neuron firing rates decreased as distractors were added to the display.

This decrease reduced the target-related response, which in turn correlated with the set-size related increase in reaction time. This suggests that distractors trigger competitive visuo-visual interactions that limit the brain's ability to find and focus on a task-relevant target.

Citation: Balan PF, Oristaglio J, Schneider DM, Gottlieb J (2008) Neuronal correlates of the set-size effect in monkey lateral intraparietal area. PLoS Biol 6(7): e158. doi:10.1371/ journal.pbio.0060158 (biology.plosjournals.org/perls… journal.pbio.0060158)

Source: Public Library of Science

Explore further: Team defines new biodiversity metric

add to favorites email to friend print save as pdf

Related Stories

Measuring the auditory dynamics of selective attention

Aug 22, 2008

Call it the cocktail party effect: how an individual can participate in a one-on-one conversation within a cluster of people, switch to another, pick up important comments while tuning out others, change topics and return ...

Older adults not more distractible, research shows

Nov 04, 2007

Despite previous research suggesting that older adults are more distractible, new research shows they are no more distractible than younger adults when asked to focus their attention on their sense of sight or sound, or when ...

Recommended for you

Team defines new biodiversity metric

2 hours ago

To understand how the repeated climatic shifts over the last 120,000 years may have influenced today's patterns of genetic diversity, a team of researchers led by City College of New York biologist Dr. Ana ...

Danish museum discovers unique gift from Charles Darwin

6 hours ago

The Natural History Museum of Denmark recently discovered a unique gift from one of the greatest-ever scientists. In 1854, Charles Darwin – father of the theory of evolution – sent a gift to his Danish ...

User comments : 0