Scientists have long hypothesized that our thoughts, emotions, and behaviors are the product of billions of interconnected neurons that communicate with one another to allow for communication between different parts of the brain.
When we think of the human brain, we usually assume a round shape with squiggly lines, almost like squished spaghetti. It, however, is much more complex than mere squiggles.
The brain's size, curves, and grooves may have a greater impact on how we think, feel, and act than the connections and messages between neurons, according to a study published on May 31 in the journal Nature.
A research team in Australia performed MRI scans on the brains of 255 volunteers while they were engaged in activities like tapping their fingers or memorizing a series of images.
To further evaluate the impact of brain shape, the scientists looked at 10,000 distinct maps of people's brain activity compiled from more than 1,000 trials conducted worldwide.
They then developed a computer model to simulate how the size and form of a brain affect electrical activity waves or brain waves. They compared that model to an earlier computer simulation of brain activity that closely matched the theory that neuronal connection is the primary regulator of brain activity.
The contrast revealed that the new model, as opposed to the old one, offered a more precise reconstruction of the brain activity depicted in the MRI images and brain activity maps.
The study's lead author James Pang from Monash University in Australia, compared the importance of brain shape to a pebble creating waves in a pond: The size and form of the pond influence the type of waves made.
"The geometry is pretty important because it guides how the wave would look, which in turn relates to the activity patterns that you see when people perform different tasks," shares Pang.
According to Washington University in St. Louis neuroscience professor David Van Essen, the brain shape theory has been discussed for over ten years. However, he claimed that most researchers continue to support the conventional approach, which holds that each of the brain's nearly 100 billion neurons, or nerve cells, contains an axon that serves as a wire to transmit information to other neurons, enabling brain activity.
"The fundamental starting hypothesis is that the wiring of the brain is central to understanding how the brain functions," continues Van Essen.
According to Pang, his findings don't minimize the importance of neuronal communication; rather, it raises the possibility that the geometry of the brain is crucial to brain function. "What the work is showing is that the shape has a stronger influence, but it's not saying that connectivity is not important," says Pang.
The brain shape theory, per Pang, has the benefit of being simpler to measure than brain circuitry; thus, paying more attention to the size or curves of the brain may lead to new lines of inquiry.