MELBOURNE, Australia — The shape of the brain in smart individuals differs from others, recent research suggests. Scientists in Australia say the geometry of the brain seems to exert a substantial influence on our cognition, emotions, and behavior — surpassing even the impact of complex neural connections. They believe that the form and structure of the brain might unlock the secrets of intelligence, providing novel insights into Alzheimer’s and other neurological diseases.
This breakthrough also simplifies our understanding of brain functioning, development, and aging, according to the scientists.
“The work opens opportunities to understand the effects of diseases like dementia and stroke by considering models of brain shape, which are far easier to deal with than models of the brain’s full array of connections,” explains lead author Dr. James Pang, a psychologist at Monash University in Australia.
“We have long thought that specific thoughts or sensations elicit activity in specific parts of the brain, but this study reveals that structured patterns of activity are excited across nearly the entire brain, just like the way in which a musical note arises from vibrations occurring along the entire length of a violin string, and not just an isolated segment,” Pang continues in a media release.
The human brain vibrates?
This research may pave the way for innovative methods to enhance cognitive abilities. Utilizing magnetic resonance imaging (MRI) scans, the Australian team analyzed patterns of vibrations or oscillations, known as eigenmodes. Although this natural phenomenon has been widely employed in physics and engineering, its application to the study of the brain is a new phenomenon.
“Just as the resonant frequencies of a violin string are determined by its length, density and tension, the eigenmodes of the brain are determined by its structural––physical, geometric and anatomical––properties, but which specific properties are most important has remained a mystery,” adds co-lead author, Dr. Kevin Aquino of BrainKey and The University of Sydney.
Your brain’s curves determine the ‘sounds’ it produces
By comparing different patterns of activity in brain models, the researchers isolated the effects of shape versus connectivity. They discovered that the brain’s geometry — its contours and curvature — significantly influenced brain function, much like how the shape of a drum determines the sounds it can produce.
“We found that eigenmodes defined by brain geometry––its contours and curvature––represented the strongest anatomical constraint on brain function, much like the shape of a drum influences the sounds that it can make,” says co-lead author Professor Alex Fornito from Monash.
“Using mathematical models, we confirmed theoretical predictions that the close link between geometry and function is driven by wave-like activity propagating throughout the brain, just as the shape of a pond influences the wave ripples that are formed by a falling pebble,” Fornito continues.
“These findings raise the possibility of predicting the function of the brain directly from its shape, opening new avenues for exploring how the brain contributes to individual differences in behavior and risk for psychiatric and neurological diseases.”
The team obtained over 10,000 MRI maps as individuals performed diverse tasks designed to probe the human brain. The findings showed that activity was dominated by eigenmodes with spatial patterns over very long wavelengths of more than one-and-a-half inches.
“This result counters conventional wisdom, in which activity during different tasks is often assumed to occur in focal, isolated areas of elevated activity, and tells us that traditional approaches to brain mapping may only show the tip of the iceberg when it comes to understanding how the brain works,” Dr. Pang concludes.
Published in the journal Nature, this study opens up new possibilities for the treatment and prevention of intellectual disabilities.
The human brain, composed of billions of electrically excitable neurons that receive, process, and transmit information through electrical and chemical signals, forms a myriad of neural pathways. Each new experience creates a fresh pathway, potentially altering future behavior. These pathways strengthen with repeated experiences and can solidify into a learned skill with further repetition.
South West News Service writer Mark Waghorn contributed to this report.