In most scientific studies involving our own species, a specific group of people is chosen and assessed by the scientists leading the study. It’s particularly rare that it’s the scientists themselves being examined, but one Stanford psychologist decided to do just that by monitoring his own brain activity for a year and a half. His results are published in Nature Communications, and reveal that the brain, as many suspected, is incredibly adaptable to changing external conditions.
Every Tuesday and Thursday morning, for 18 months, Russell Poldrack of Stanford University scanned his brain, and monitored how his neurological activity changed over time. For 10 minutes each of those mornings, he popped his head into a magnetic resonance imaging (MRI) scanner, a device that can track the flow of blood in the body. When a particular region of the brain is used, the blood flow to it increases, enlightening scientists and medical researchers as to how the brain is operating when the person is behaving in a specific way.
The main aim of this study was to determine how different parts of the brain speak to each other and modify themselves, from the visual centers to those that control movement. It’s well known that the brain possesses the remarkable ability to reorganize itself. This trait, known as “plasticity,” means that if one section of the brain is damaged or altered in some way, it can call on other sections of the brain to pick up the slack.
These various brain sections “correspond” with each other using a network called the connectome. Researchers have previously mapped this network using MRI scanners, essentially making them neural cartographers. An engineer might refer to this map as the brain’s “wiring diagram.”
The MRI in this case looked at the connectome of Poldrack’s brain. The data set is so huge that there is an ongoing effort to establish what exactly happened during the experiment, but the initial results have been released. Although his overall connectivity did not change much over the 18 months, changes in his behavior caused rapid changes in his neurological activity.
In the most notable example, he fasted and cut out his regular morning coffee before his Tuesday scan. The scans showed that the connections between the systems in the brain responsible for vision and those associated with the sense of touch, pressure, pain, temperature, position, movement, and vibration – the somatosensory system – became far tighter when he reduced his caffeine and food intake.
A visualization of part of the connectome, showing how coffee and food intake affects the connections between the various regions of the brain. The red region is the somatosensory region; the blue is part of the visual system. Image credit: Poldrack et al./Nature Communications
“We don't really know if [this is] better or worse, but it's interesting that these are relatively low-level areas,” Poldrack said in a statement. “It may well be that I'm more fatigued on those days, and that drives the brain into this state that's focused on integrating those basic processes more.”
Of course, there is still much more to look at in this enormous data set. “The one big thing we are looking at now is now connectivity changes in the very short term, over the course of seconds,” Poldrack told IFLScience. “Our previous analyses all assumed that connectivity was constant across each 10 minute scan, but we know that’s not the case, so now we are trying to unpack more precisely the way that it varies over time.”
It is worth noting that although this is an unprecedentedly detailed study, it was only conducted on one subject. Regardless, by analyzing his own brain for this length of time, Poldrack has one of the most studied brains in the world.