Researchers have found that the shape of a person’s brain profoundly influences thinking, feeling, and behavior, overturning the existing focus on complex neural communications. Using MRI scans and principles of autocoding, they found that brain function is closely related to its geometric properties, such as how the shape of a musical instrument determines the sound, providing new avenues for investigating brain function and disease.
The shape of our brain rather than the interaction between different regions plays a significant role in influencing our thoughts, emotions and actions.
For more than a hundred years, scientists have believed that our thoughts, feelings, and dreams are shaped by the way different brain regions interact across a vast network of trillions of cellular connections.
However, a recent study led by a team at Monash University’s Turner Institute of Brain and Mental Health examined more than 10,000 different maps of human brain activity and found that the general shape of an individual’s brain has a greater influence on cognitive processes, emotions and behavior than complex neural connectivity.
A study recently published in a prestigious journal, alam He brings together approaches from physics, neuroscience, and psychology to reverse a century-old paradigm that emphasizes the importance of complex brain connectivity, and instead identify previously underappreciated connections between brain shape and activity.
Lead author and co-researcher Dr James Bang, of the Turner Institute and Monash University School of Psychological Sciences, said the findings were important because they greatly simplify the way we can study how the brain works, develops and ages.
Alex Fornetto (left) and James Pang studied more than 10,000 MRI images to determine important brain shapes. Credit: Monash University
“This work opens up opportunities to understand the effects of diseases such as dementia and stroke by looking at models of the shape of the brain, which are easier to work with than models of the entire set of connections in the brain,” said Dr. Pang.
“We have long thought that certain thoughts or sensations trigger activity in certain parts of the brain, but this research reveals that organized patterns of activity are stimulated in almost the entire brain, much like the way musical notes emerge from vibrations occurring along the strings of a violin, not just isolated sections,” he said.
The research team used magnetic resonance imaging (MRI) to study eigenmodes, which are natural patterns of vibration or excitation in a system, in which different parts of the system are excited at the same frequency. Automodules are commonly used to study physical systems in fields such as physics and engineering, and have only recently been adapted to study the brain.
This work focuses on developing the best way to efficiently construct eigenmodes for the brain.
Co-lead author Dr Kevin Aquino, from BrainKey and the University of Sydney, said: “Just as the resonant frequency of a violin string is determined by length, density and tension, the eigenmodes of the brain are determined by their structural properties – physical, geometric and anatomical -, but the specific properties that matter most remain a mystery.”
The team, led by the Turner Institute and ARC School of Psychological Science Fellow Professor Alex Fornetto, compared how subjective profiles obtained from brain shape models could explain different patterns of activity when compared to subjective profiles obtained from brain connectivity models.
“We found that the eigenmodes determined by the geometry of the brain – their contours and curvatures – represent the strongest anatomical constraints on brain function, just as the shape of a cylinder influences the sound it makes,” said Professor Fornetto.
“Using a mathematical model, we confirmed the theoretical prediction that the close relationship between geometry and function is driven by wave-like activity that propagates throughout the brain, just as the shape of a pond influences wave ripples formed by falling pebbles,” he says.
“These findings increase the possibility of predicting brain function directly from its shape, opening new avenues for exploring how the brain contributes to individual differences in behavior and risk of psychiatric and neurological diseases.”
The research team found that in more than 10,000 MRI activity maps, which were obtained when subjects performed various tasks developed by neuroscientists to explore the human brain, the activity was dominated by subjective patterns with spatial patterns having very long wavelengths, stretching to distances of more than 40 millimeters.
“These findings contradict conventional wisdom, in which activity during multiple tasks is often assumed to occur in areas of focus and isolated from high activity, and tells us that traditional brain mapping methods may only represent the tip of the iceberg when it comes to understanding how the brain works,” said Dr. Pang.
Reference: “Engineering Limitations of Human Brain Function” By James C. Pang, Kevin M. Aquino, Marian Oldenkel, Peter A. Robinson, Ben de Fulcher, Michael Breakspeare, Alex Fornetto, 31 May 2023, Available Here. alam.
DOI: 10.1038/s41586-023-06098-1
2023-07-22 04:02:11
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