In the early 1900s, Korbinian Brodmannand his mentors, Oskar and Cecile Vogt, divided the brain into well-defined regions known as parcels, which are based on the degree of similarity between their cellular architecture. Later, Percival Bailey and Gerhardt von Bonin challenged this idea, claiming that reality was not clear-cut and that differences between regions were gradual.
In 2020, a group at the University of Malta created the Vogt-Bailey (VB) toolbox to test the two contrasting ideas of brain organisation. The software uses a mathematics branch called spectral graph theory to unveil brain boundaries. It calculates a VB index at every point in the brain, ranging from zero to one, measuring the level of synchronised activity of neighbouring 3D brain pixels. These indices are used to create the final VB map which displays brain boundaries. This toolbox can be used to investigate how boundaries change in different states, tasks or disorders such as autism or depression.
This toolbox can be used to investigate how boundaries change in different states, tasks or disorders such as autism or depression
The group’s current research focuses on understanding what level of certainty we can attach to the obtained VB-index values. To better understand this concept, consider a situation where it is announced that 500 people will become infected with COVID-19 in the next month. What does this value mean? Will exactly 500 people become infected? Will the value be between 50 and 1000 people? Or will we be more certain of a smaller interval (for example, between 400 and 600)? This “quantification of certainty” is the problem that statistics can solve.
This is what the team aims to do with current work. After estimating the VB indices across the brain, we estimate the interval between which the true value lies. This allows us to be more confident when we answer the question that the early-20th-century neuroscientists posed; can the brain truly be divided up into separate regions?
The team behind this “beyond the brain boundaries” (Be-BOB) project, financed by the University of Malta’s Research Excellence Grant (Grant number 202201), involves people from different backgrounds including medicine, engineering and statistics.
• Current research conducted by the team at the University of Malta has used this VB Toolbox to investigate how these brain boundaries are altered in patients with autism relative to controls. The brains of controls exhibited lower VBI values in various sensory regions, including the occipital lobe which is related to vision.
• Another student used the tool to investigate brain boundary changes according to varying degrees of visual imagery vividness. We did not find any correlations between vividness and VBI measures.
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DID YOU KNOW?
• The nervous system development starts from the back, with the frontal regions maturing last. The brain takes 25 years to fully form and strengthen its connections. Meanwhile, your spinal cord stops growing at age four.
• For proper functioning, the brain needs to forget. In fact, people with incredible episodic memories find it hard to extract the main principles of their memories.
• Although removing half your brain (hemispherectomy) would affect some cognitive function, a person can live a normal life with one half of their brain, usually maintaining their personality.
• Capgras Syndrome can occur in various brain diseases and it causes a person to believe that a family member or friend has been replaced by an imposter.
• The brain itself does not feel pain, yet is needed to detect and perceive pain from other body areas, including the layers surrounding the brain.
• Magnetic Resonance Imaging (MRI) scanners do not use harmful radiation. They use a magnetic field, four times stronger than that of the earth, to visualise brain structure and function.
For more trivia, see: www.um.edu.mt/think.