Coffee and breakfast had the biggest effect on his brain’s connectivity.
For a year and a half, Stanford researcher Russell Poldrack hopped into an MRI machine and scanned his brain for 10 minutes every Tuesday and Thursday morning. This makes his brain the most studied brain in history, and the self-experimentation led Poldrack to some striking findings about the effect of caffeine on the brain’s connectivity.
The goal of the long-term study was to gain a better understanding of the brain’s connectome, or a comprehensive map of how different parts of the brain communicate with each other. In addition to the MRI scans, Poldrack also fasted and drew blood on Tuesdays in order to further analyze the connections between brain function and gene expression.
“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,” Poldrack said in a statement. “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.”
Poldrack was surprised to see how much of an effect both coffee and breakfast had on his brain activity. On Tuesday mornings, Poldrack scanned his brain before his morning cup of coffee — the connectivity in his decaffeinated brain looked very different from that in his caffeinated brain. Specifically, the connection between the somatosensory motor network and the systems responsible for high vision became much tighter without caffeine.
“Easily the biggest factor we found in terms of affecting my brain connectivity was whether I had had breakfast and caffeine or not,” Poldrack said. “That was totally unexpected, but it shows that being caffeinated radically changes the connectivity of your brain. We don’t really know if it’s better or worse, but it’s interesting that these are relatively low-level areas.”
Additionally, Poldrack’s brain connectivity was surprisingly consistent throughout the 18 months, but he says this is likely due to his calm emotional state. “I’m generally a pretty happy and even-keeled person,” he says. “My positive mood is almost always high, and my negative mood is almost always non-existent. It would be interesting to scan people with a wider emotional variation and see how their connections look over time.”
The extensive data also unearthed a strong correlation between brain activity and changes in the expression of a number of different gene families. The researchers found that the expression of genes related to inflammation and immune response matched Poldrack’s psoriasis flare-ups, which is a common condition in which skin cells build up and form itchy, dry patches and scales.
Since the dataset is so large, Poldrack and his team have made it available online, along with the ready-built tools to analyze it. They hope that other people will approach the data and use innovative methods to establish new connections that will advance the research.
In the meantime, Poldrack plans to improve software that interprets the interplay between brain function and gene expression.
“It’s a hard dataset to know what to do with, because it’s hard to tell if something is noise or if it’s real with just one person. But there’s potentially some really interesting stuff here,” he adds. “There are a ton of relationships between brain connectivity and gene expression in the blood, that are clearly there and seem to be strong, but we just don’t have a way to understand them based on current neuroscience.”
Take a look at the data here. Perhaps you’ll be the one to help Poldrack and his team discover something fascinating.
Or watch Poldrack explain the research in Stanford’s video below.