Graph Theory in Brain Studies
The brain is for sure the most complicated organ on the human bodies, and thus it has long been the focus of multiple medical researches. Have you ever wondered where in your brain you exist, or if your awareness is produced by series of changes or a tiny change in a specific part of your brain? The researchers from Vanderbilt University recently conducted a brain imaging study and are able to answer these longstanding questions. They discovered that the awareness process is correlated with a series of global changes in the entire brain area instead of a single brain part. One of the leading professors believes these findings are of high importance for further medical research and have philosophical implications on the underpinnings of the human experience.
Using the functional magnetic resonance imaging (fMRI) experimentation method, the researchers were able to utilize graph theory to explain the communication in human brains. The black nodes represent different areas of the cerebral cortex that they probed, and the lines correspond to the connections between different brain areas. The redness of the color shows the strength of the perceived connection. In the experiment, participants were asked to detect a disk that was briefly flashed on a screen, and their answer decides whether they were “aware” or “unaware”. Unlike the previous experiments that focus on what regions were more activated with awareness, this research aims at discovering how the different networks communicate with each other. The result suggests that consciousness and awareness are products of a widespread communication that happen among networks of “attention”, “language”, “control”, etc. In other word, the awareness does not stay in a specific part of the brain, but is dependent on a fast and pervasive propagation throughout the brain.
This reminds me of the small world phenomenon that mentioned in the book. Although different functionality areas of the brain seem irrelevant, a connection between two single dots from the respective group will link two irrelevant areas, just like how people can relate to someone overseas. Therefore, it is not irrational to say that the path between different networks is incredibly short. This is how the networks of “language” cortex interact with the networks of “visual” cortex interacting, and a couple of similar interactions give rise to the formation of awareness and consciousness. Although the “six degrees of separation” is more like an exaggeration, it consummately illustrates the closeness of different networks, no matter in human interactions or in body organs’ interactions. This research also suggests the high potential of graph theory application into scientific researches.
Research link: http://news.vanderbilt.edu/2015/03/213466/