Human working memory is based on dynamic interaction networks in the brain

April 13, 2010

A research project of the Neuroscience Center of the University of Helsinki sheds light on the neuronal mechanisms sustaining memory traces of visual stimuli in the human brain. The results show that the maintenance of working memory is associated with synchronisation of neurons, which facilitates communication between different parts of the brain. On the basis of interaction between the brain areas, it was even possible to predict the subject's individual working memory capacity. The results were published last week in the online version of the renowned journal PNAS.

The working memory of an average person can sustain only three of four objects at a time. The brain areas maintaining the working memory are known well, but there is little information about how these areas interact. The research group led by Satu and Matias Palva imaged the brain activity of subjects performing working memory tasks by using magneto- and electroencephalography (MEG and EEG). In addition to this, they developed a new method for using MEG and EEG data to identify networks of fast neuronal interactions, i.e., synchrony, between different areas of the cerebral cortex. With this novel approach, it was possible to reveal functional networks formed by brain areas at the accuracy of milliseconds.

Maintaining of a memory trace synchronised different brain areas

In their study, the researchers mapped almost four billion different neuronal interactions. They were especially interested in rhythmic interactions between different parts of the brain. While sustaining the working memory of visual stimuli, the rhythmic activity of the subject's different brain areas were transiently synchronised. The results reveal that the synchronisation of neuronal activity in different brain areas had a connection both to the maintenance and to the contents of working memory.

The study also revealed several specialized function-specific networks and interactions between them. The network comprising different areas of the brain's frontal and parietal lobes played a central role. These areas are responsible for the coordination of attention and action. The networks in the occipital lobe, on the other hand, handle and maintain the sensory information about the visual stimuli.

Working memory and attention are the cornerstones of our cognition and consciousness - knowledge about their underlying neuronal mechanisms can be applied, for example, when developing therapeutic and diagnostic methods for Alzheimer's disease, dementia, schizophrenia, perception and learning disorders, autism and other brain diseases.
-end-
Additional information:
Project Leader, Docent Matias Palva
The Neuroscience Center of the University of Helsinki
matias.palva@helsinki.fi
Tel. +358 9 191 57613

University of Helsinki

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.