Neuroscience reveals complexity of human brain networks

Credit: University of Oregon

Nicki Swann, Assistant Professor of Human Physiology

Credit: University of Oregon

Alex Roxhill (First Author, Human Physiology Graduate Student)

Scientists detected simple movement like pushing a button sends ripples of activity throughout networks of neurons spanning across the brain.

Why this is important:

The finding highlights just how complex the human brain is, challenging the simplified textbook picture of distinct brain areas dedicated to specific functions.
The study, a collaboration between University of Oregon (UO) human physiologists and Oregon Health and Science University (OHSU) researchers, published in December in the Journal of Neural Engineering.
The phenomenon probably isn’t limited to movement, either. Other systems, like vision and touch, are also probably extending through more of the brain than previously appreciated.

How it works:

The OHSU team is using a technique called intracranial EEG to determine where seizures may be starting in patients with treatment-resistant epilepsy.
Intercranial EEG involves surgically implanting an array of electrodes into patients’ brains, allowing doctors to pinpoint precisely when and where in the brain a seizure is happening and potentially remove the affected brain area.
Human physiologist Nicki Swann and colleagues gave study participants a simple movement-related task—pushing a button.
They recorded the activity of thousands of neurons throughout the brain while participants were doing the task.
“We found there's a spectrum of brain areas, from primary motor areas where you can decode that the person is moving 100% of the time, to other areas that respond like 75% of the time,” added Alex Rockhill, the first author on the paper. In some of the areas that don’t specialize in movement, “some of the neurons might be firing, but they might be overwhelmed by neurons that are not movement-related.”

Background & Next Steps

Their findings compliment a study published in 2019 in the journal Nature, in which other researchers showed similar far-reaching brain networks related to movement in mice.
“That paper showed that movement is everywhere in the brain — and our paper shows that’s true in humans too,” Swann said.
Now, the team is working on developing new tasks that involve different kinds of movement, to see how those show up in the brain. And they plan to keep growing the collaboration with OHSU, involving more researchers in the project and gaining a deeper understanding of the brain’s intricacies.

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