News | March 13, 2012

Diffusion Spectrum Imaging Identifies How the Brain Selects What We Want To See

February 21, 2012 - If you are looking for a particular object -- say a yellow pencil -- on a cluttered desk, how does your brain work to visually locate it?

For the first time, a team led by Carnegie Mellon University (CMU) neuroscientists has identified how different neural regions communicate to determine what to visually pay attention to and what to ignore. This finding is a major discovery for visual cognition and will guide future research into visual and attention deficit disorders.

The study, published in the Journal of Neuroscience, used various brain imaging techniques to show exactly how the visual cortex and parietal cortex send direct information to each other through white matter connections in order to specifically pick out the information that you want to see.

The researchers used a technique called diffusion spectrum imaging, a new magnetic resonance imaging (MRI) procedure pioneered at Carnegie Mellon and the University of Pittsburgh to generate the fiber tracts of the white matter connectivity. This method was combined with high-resolution tractography and provides scientists with better estimates of the hard-wired connections between brain regions and increased accuracy over conventional tractography methods, such as those typically used with diffusion tensor imaging.

"We have demonstrated that attention is a process in which there is one-to-one mapping between the first place visual information comes from the eyes into the brain and beyond to other parts of the brain," said Adam S. Greenberg, postdoctoral fellow in the Dietrich College of Humanities and Social Sciences' Department of Psychology and lead author of the study.

"With so much information in the visual world, it's dramatic to think that you have an entire system behind knowing what to pay attention to," said Marlene Behrmann, professor of psychology at CMU and a renowned expert in using brain imaging to study the visual perception system. "The mechanisms show that you can actually drive the visual system — you are guiding your own sensory system in an intelligent and smart fashion that helps facilitate your actions in the world."

For the study, the research team conducted two sets of experiments with five adults. They first used several different functional brain scans to identify regions in the brain responsible for visual processing and attention. One task had the participants look at a dot in the center of the screen while six stimuli danced around the dot. The second task asked the participants to respond to the stimuli one at a time. These
scans determined the regions in both the visual and parietal cortices. The researchers could then look for connectivity between these regions.

The second part of the experiment collected anatomical data of the brain's white matter connectivity while the participants had their brains scanned without performing any tasks. Then, the researchers combined the results with those from the functional experiments to show how white matter fibers tracked from the regions determined previously, the visual cortex and the parietal cortex. The results demonstrated that the white matter connections are mapped systematically, meaning that direct connections exist between
corresponding visual field locations in visual cortex and parietal cortex.

"The work done in collaboration with the University of Pittsburgh researchers exploits a very new, precise and cutting edge methodology," Behrmann said.

"Because we know that training can alter white matter, it might be possible, through training, that the ability to filter out irrelevant or unwanted information could be improved," Greenberg said.

Additional researchers on this study included Timothy Verstynen, a research associate in the University of Pittsburgh's Learning Research and Development Center, Yu-Chin Chiu, a post-doc in University of California, San Diego's Department of Psychology, Steven Yantis, professor of psychological and brain sciences at the Johns Hopkins University and Walter Schneider, professor of psychology at the
University of Pittsburgh. Greenberg, Behrmann, Verstynen and Schneider are also members of the Center for the Neural Basis of Cognition (CNBC), a joint project between Carnegie Mellon and the University of Pittsburgh devoted to investigating neural mechanisms and their impact on human cognitive abilities.

The National Institutes of Health funded this research.

For more information: http://www.jneurosci.org.

Related Content

Black Men Less Likely to Adopt Active Surveillance for Low-Risk Prostate Cancer
News | Prostate Cancer | June 17, 2019
A new study reveals black men are less likely than white men to adopt an active surveillance strategy for their...
International Working Group Releases New Multiple Myeloma Imaging Guidelines

X-ray images such as the one on the left fail to indicate many cases of advanced bone destruction caused by multiple myeloma, says the author of new guidelines on imaging for patients with myeloma and related disorders. Image courtesy of Roswell Park Comprehensive Cancer Center.

News | Computed Tomography (CT) | June 17, 2019
An International Myeloma Working Group (IMWG) has developed the first set of new recommendations in 10 years for...
SyMRI Software Receives FDA Clearance for Use With Siemens MRI Systems
Technology | Magnetic Resonance Imaging (MRI) | June 14, 2019
SyntheticMR announced U.S. Food and Drug Administration (FDA) clearance for clinical use of its SyMRI Image and SyMRI...
A high-fidelity 3-D tractography of the left ventricle heart muscle fibers of a mouse

Figure 1. A high-fidelity 3-D tractography of the left ventricle heart muscle fibers of a mouse from Amsterdam Ph.D. researcher Gustav Strijkers.

News | Magnetic Resonance Imaging (MRI) | June 07, 2019
The Amsterdam University Medical Center has won MR Solutions’ Image of the Year 2019 award for the best molecular...
Study Identifies MRI-Guided Radiation Therapy as Growing Market Segment
News | Image Guided Radiation Therapy (IGRT) | June 06, 2019
Revenues from the magnetic resonance imaging (MRI)-guided radiation therapy systems market exceeded $220 million in...
Ann Arbor Startup Launches Augmented Reality MRI Simulator
Technology | Virtual and Augmented Reality | June 04, 2019
SpellBound, an Ann Arbor startup specializing in augmented reality (AR) tools for children in hospitals, has officially...
AI Biomarker Demonstrates High Predictive Power for Lung Cancer Immunotherapy
News | Artificial Intelligence | May 31, 2019
Lunit announced an abstract presentation of its artificial intelligence (AI) precision medicine research portfolio at...

Photo courtesy of Philips Healthcare

Feature | Radiology Business | May 31, 2019 | By Arjen Radder
Change is a consistent theme in our world today, no matter where you look.
Dynamic Digital Radiography Used to Assess Undifferentiated Dyspnea
News | Digital Radiography (DR) | May 29, 2019
A clinical study presented at the American Thoracic Society (ATS) 2019 annual meeting, May 17-22 in Dallas, described...
Leica Biosystems Receives FDA Clearance for Aperio AT2 DX Digital Pathology System
Technology | Digital Pathology | May 29, 2019
Leica Biosystems has received clearance from the U.S. Food and Drug Administration (FDA) to market its Aperio AT2 DX...