Functional brain imaging insights from UC San Diego grad student

December 06, 2006

December 06, 2006 -- David Wipf, a recent graduate of the electrical and computer engineering Ph.D. program at UC San Diego's Jacobs School of Engineering, has won a 2006 Outstanding Student Paper Award at a prestigious conference for his work on human functional brain imaging. The conference -- the 2006 Neural Information Processing Systems Conference or NIPS is being held in Vancouver this week.

"With this work, functional brain imaging practitioners should be better able to assess the relative strengths and weaknesses of competing Bayesian approaches for source localization," said David Wipf, who performed the research and wrote the paper while at UCSD.

"NIPS is a premier conference and this is quite an achievement," said Bhaskar Rao, an ECE professor at UCSD's Jacob's School and David Wipf's Ph.D. dissertation advisor.

The new work, which is largely theoretical, may also lead to improvements of existing algorithms that attempt to determine what parts of the brain are producing the electromagnetic fields that are measured by functional brain imaging techniques such as magnetoencephalography (MEG) or closely-related electroencephalography (EEG).

MEG and EEG use an array of sensors to take electromagnetic field measurements from on or near the scalp surface with excellent temporal resolution. Using this information to create accurate maps of neural activity with the highest possible spatial and temporal resolution, and relating these time-and-space activity patterns to behavioral, perceptual, cognitive and motor processes is one of the ultimate goals of human functional brain imaging. However, determining exactly what parts of the brain produce the electromagnetic fields is a difficult and unresolved issue.

Researchers often use Bayesian statistical methods and algorithms to try to determine the source, within the brain, of recorded neuroelectromagnetic fields. Trying to answer the source localization question requires the incorporation of prior assumptions -- and Bayesian methods are useful in this capacity because they allow these assumptions to be quantified. There are, however, many different Bayesian approaches for researchers to choose from; and it is difficult to know which approach is right for any given experimental situation.

In their new paper, David Wipf and colleagues at UCSD's Signal Processing and Intelligent Systems Lab and UCSD's Swartz Center for Computational Neuroscience stepped back and studied many of these Bayesian approaches. Their work yielded a generalized framework that encompasses many of the established Bayesian techniques for imaging neural activity.

The paper took one of three 2006 Outstanding Student Paper Awards at NIPS, chosen from a pool of 62 nominations. David Wipf is the first author and his coauthors -- Rey Ramírez, Jason Palmer, Scott Makeig and Bhaskar Rao -- are all from UCSD. The paper is entitled "Analysis of Empirical Bayesian Methods for Neuroelectromagnetic Source Localization."

Wipf and colleagues conclude their paper with the following: "By developing a general framework around the notion of automatic relevance determination (ARD), deriving several theoretical properties and showing connections between algorithms, we hope to bring an insightful perspective to these techniques."

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 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