MIT model helps researchers 'see' brain development

April 9, 2007
MIT model helps researchers 'see' brain development
Larger-scale folds develop the fastest in premature (born more than seven weeks early) infants (top), while medium-scale folds develop the fastest in older premature infants, born between seven and two weeks early (middle). In older infants and children, fine folds develop the most quickly across the brain surface (bottom). Image: Peng Yu

Large mammals--humans, monkeys, and even cats--have brains with a somewhat mysterious feature: The outermost layer has a folded surface. Understanding the functional significance of these folds is one of the big open questions in neuroscience.

Now a team led by MIT, Massachusetts General Hospital and Harvard Medical School researchers has developed a tool that could aid such studies by helping researchers “see” how those folds develop and decay in the cerebral cortex.

By applying computer graphics techniques to brain images collected using magnetic resonance (MR) imaging, they have created a set of tools for tracking and measuring these folds over time. Their resulting model of cortical development may serve as a biomarker, or biological indicator, for early diagnosis of neurological disorders such as autism.

The researchers describe their model and analysis in the April issue of IEEE Transactions on Medical Imaging.

Peng Yu, a graduate student in the Harvard-MIT Division of Health Sciences and Technology (HST), is first author on the paper. The work was led by co-author Bruce Fischl, associate professor of radiology at Harvard Medical School, research affiliate with the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL) and HST, and director of the computational core at the HST Martinos Center for Biomedical Imaging at Massachusetts General Hospital (MGH).

The team started with a collection of MR images from 11 developing brains, provided by Ellen Grant, chief of pediatric radiology at MGH and the Martinos Center. Of the subjects scanned, eight were newborn, mostly premature babies ranging from about 30 to 40 weeks of gestational age, and three were from children aged two, three and seven years. Grant scanned these infants and children to assess possible brain injury and found no neural defects. Later, she also consulted with Fischl's team to ensure that their analyses made sense clinically.

“We can't open the brain and see by eye, but the cool thing we can do now is see through the MR machine,” a technology that is much safer than earlier techniques such as X-ray imaging, said Yu.

The first step in analyzing these images is to align their common anatomical structures, such as the “central sulcus,” a fold that separates the motor cortex from the somatosensory cortex. Yu applied a technique developed by Fischl to perform this alignment.

The second step involves modeling the folds of the brain mathematically in a way that allows the researchers to analyze their changes over time and space.

The original brain scan is then represented computationally with points. Charting each baby's brain requires about 130,000 points per hemisphere. Yu decomposed these points into a representation using just 42 points that shows only the coarsest folds. By adding more points, she created increasingly finer-grained domains of smaller, higher-resolution folds.

Finally, Yu modeled biological growth using a technique recommended by Grant that allowed her to identify the age at which each type of fold, coarse or fine, developed, and how quickly.

She found that the coarse folds, equivalent to the largest folds in a crumpled piece of paper, develop earlier and more slowly than fine-grained folds.

In addition to providing insights into cortical development, the team is now comparing the images to those being collected from patients with autism. “We now have some idea of what normal development looks like. The next step is to see if we can detect abnormal development in diseases like autism by looking at folding differences,” said Fischl. This tool may also be used to shed light on other neurological diseases such as schizophrenia and Alzheimer's disease.

Source: Massachusetts Institute of Technology

Explore further: Smart helmets save lives, improve rides

Related Stories

Smart helmets save lives, improve rides

November 6, 2015

As technological advancements enable people to run faster, ride farther and hit harder, experts are using sensors to collect data that could reduce head trauma incidents for football, hockey, cycling and other sports.

How dung beetles navigate

November 2, 2015

Researchers got right into the brains of dung beetles to find out how they use celestial cues such as the sun, the moon and the polarisation pattern of skylight to navigate their dung balls along straight paths across the ...

COMPASS method points researchers to protein structures

October 15, 2015

Searching for the precise, complexly folded three-dimensional structure of a protein can be like hacking through a jungle without a map: a long, intensive process with uncertain direction. University of Illinois researchers ...

How moths integrate sensory and control information

September 21, 2015

It's difficult enough to see things in the dark, but what if you also had to hover in midair while tracking a flower moving in the wind? That's the challenge the hummingbird-sized hawkmoth (Manduca sexta) must overcome while ...

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

( -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.