For centuries, doctors and neuroscientists have hypothesized and (literally) dissected the brain to learn more about it and how it works. Years of attempts at “brain-mapping” and scribbling in lab notebooks has led the scientific community to a series of answers, as well as controversy. Now, thanks to Matthew F. Glasser and his team at the Washington University School of Medicine, the former is coming much more than the latter.
Due to individual variants and small subject groups, mapping the brain has only been partially successful. In 1909, scientist Korbinian Brodmann made a name for himself by becoming one of the first people to attempt to draw out the human cortex using only the cellular architecture that he observed in his microscope.
For over a hundred years, neuroanatomists have used his diagrams as a functional blueprint of the human mind. Even though his original research has been improved and supplemented throughout the years, a more stable foundation on which to build for the future has been long overdue.
Enter Dr. Glasser’s Human Connectome Project, which aspires to digitize the brain’s structures and functions on a large-scale map. Although this had been attempted before, criticism was drawn due to the relatively small sample size and the high variability in human brain structures.
This time, however, two hundred and ten healthy adults had their brains observed by a machine that had been programmed to recognize the multi-modal “fingerprint” of each part of the brain. Essentially, instead of just mapping each specific flap and fold, the researchers were looking for distinct combinations of myelin – a fatty neuron insulator – and brain activity while test subjects performed a number of different activities. The aim was to identify regions of the brain that “light up” when engaged.
For instance, one popularized area of the brain, Broca’s area, has long been known to be responsible for speech. Not surprisingly, this was confirmed in Dr. Glasser’s research, as were the 83 other known areas of the brain. However, the study also confirmed the existence of almost one hundred other regions. This hypothesis was then confirmed when they tested the map on two hundred and ten brand-new subjects and were able to identify their brain regions, give or take some level of individual variability.
Some of these new brain regions are still mysteries to even the scientists who discovered them. Like islands that have been discovered but not named yet, many of these areas have only been identified, not fully explored. For instance, a small patch of the brain (near Broca’s area) that is not rich in myelin has been discovered to become “unusually active” when people listen to stories. For the time being, it has been designated in research notebooks as 55b, an extension of Broca’s area.
In addition, several areas previously designated as one zone (like the dorsolateral prefrontal cortex – also known as the front of the brain), have been identified as smaller portions that add up to a larger whole. For instance, even though the whole prefrontal cortex is responsible for higher modes of thought, individual patches may light up depending on whether or not you’re solving a puzzle or trying to deceive someone.
Besides the obvious implications for neuroscientists and brain surgeons around the world, this change in the basic understanding of how our brains work will be immeasurably helpful in the development of new treatments for brain-based illnesses like Alzheimer’s and schizophrenia.