Every Tuesday and Thursday morning for a year and a half, Russell Poldrack started off his day by climbing into an MRI machine and scanning his brain for 10 minutes. The self-experimentation has made the psychologist’s brain the most studied in the world.
Poldrack, who began the work at the University of Texas and has continued it at Stanford University, committed himself to the long-term study in order to expand the understanding of how different parts of the brain talk to each other, an organization known as the connectome, and how that behavior changes over time.
To bolster the results, Poldrack also fasted and drew blood on Tuesdays, which was analyzed to draw connections between brain function and gene expression. This step also showed definitive—and surprising—evidence of just how the brain reorganizes itself when it’s low on coffee.
The results are published in Nature Communications.
In any action that a person undertakes, many different regions of the brain communicate with each other, serving as a sort of check-and-balance system to make sure that the correct actions are taken to deal with the situation at hand. These messages are communicated over more than a dozen networks, sets of functional areas of the brain that preferentially talk to one another.
There are multiple networks for vision, a somatosensory/motor network, and there are others that are attributed to attention or task management. Collectively, these are known as the connectome. Because the strength or efficiency of these individual networks can affect behavior, they have become of greater interest to researchers in recent years.
To isolate these connections, researchers examine functional MRI data collected while the patient (including Poldrack) is at rest.
“I would get in the MRI and basically close my eyes and zone out while it took a picture of my brain every second for 10 minutes,” he says. “Once we had that data, we could get ideas of which regions of my brain are talking to each other by how correlated they are over time. This tells us how much connectivity there is within each network.”
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