overview: A simple motion, like pressing a button, can send ripples of activity across neurons across the brain, new research reports.
sauce: University of Oregon
A new study from the University of Oregon shows that even a simple movement, like pressing a button, can send ripples of activity across networks of neurons that span the entire brain.
The findings highlight just how complex the human brain is, challenging the simplistic textbook picture of distinct brain regions dedicated to specific functions.
“It’s well known that the primary motor cortex controls motor output,” said Alex Rockhill, a graduate student in the lab of human physiology professor Nikki Swann. “But this guy has a lot more to do with movement than just one brain area.”
Rockhill is the lead author of a new paper from the Institute, which was published in December. Journal of Neuroengineering.
Swann and her team are working with doctors and researchers at Oregon Health and Science University to study human brain networks. The OHSU team is using a technique called intracranial EEG to determine where seizures are starting in patients with treatment-resistant epilepsy. pinpoint when and where is happening and potentially eliminate affected brain regions.
Intracranial EEG also provides valuable insight into other brain activity. This is the “gold standard” technique, he says, Swann. However, electrode implantation is a highly intensive process and is rarely accessible to researchers. Participants in Swann’s study agreed to let her team study the brain while connected to electrodes for seizure studies.
Swann and her colleagues gave study participants a simple, motion-related task of pressing a button. They recorded the activity of thousands of neurons throughout the brain while participants performed a task. Next, we tested whether the computer could be trained to identify whether certain patterns of brain activity were captured when participants were resting or moving.
Signals were evident in certain areas of the brain. These are areas that were formerly associated with movement, where most of the neurons probably focused on that action. But the researchers also found that brain signals predict movements throughout the brain. This includes areas not specifically dedicated to it.
Many parts of the brain “can predict very well whether the data is in motion or not,” Swann said.
“We found that there are different brain regions, from the primary motor cortex that can decode that a person is moving 100% of the time, to other regions that can decode that 75% of the time,” Rockhill added. .
In some areas not specialized for movement, “some neurons may be firing, but they may be overwhelmed by neurons not related to movement,” he said. .
Their findings complement a study published in the journal in 2019. Natureother researchers have shown similar extensive brain networks related to movement in mice.
“That paper shows that motion is ubiquitous in the brain, and our paper shows it’s true in humans,” Swan said.
This phenomenon is probably not limited to movement. Other systems, such as sight and touch, may also be pervasive in more brains than previously recognized.
The team is now working on developing new tasks involving different types of movements and seeing how they manifest themselves in the brain. We plan to continue expanding our collaboration with OHSU to better understand the intricacies of the brain.
“This new collaboration opens up a lot of opportunities,” said Swann. “We are truly fortunate to have had the opportunity to work with the OHSU team and their wonderful patients to collect such exciting data.”
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About this neuroscience research news
author: Laurel Hamers
sauce: University of Oregon
contact: Laurel Hammers – University of Oregon
image: image is public domain
Original research: closed access.
“Stereo electroencephalography extends the known distribution of vibrations associated with standard motion” Alexander P. Rockhill et al. Journal of Neuroengineering
overview
Stereo electroencephalography extends the known distribution of vibrations associated with standard motion
Purpose. Previous electrophysiological studies have characterized canonical oscillation patterns associated with movement, mainly from recordings in the primary sensorimotor cortex. Few studies have attempted to decipher movement based on electrophysiological recordings from broader brain regions, particularly those sampled by human stereoscopic electroencephalography (sEEG). We aimed to identify and characterize different movement-related oscillations across a relatively wide sampling of human brain regions.
approach. We used linear support vector machines to decode time-frequency spectrograms time-locked to motion and validated the results with cluster permutation tests and general spatial pattern decoding.
Main results. We were able to accurately classify the sEEG spectrograms between the key-pressing task and the interval between trials. Specifically, we found the patterns previously described: beta (13-30 Hz) desynchronization, beta-synchronization (rebound), alpha (8-15 Hz) modulation before movement, broadband gamma after movement. (60-90 Hz) increase. and event-related possibilities. These oscillatory patterns were newly observed in a wide range of sEEG-accessible brain regions that are inaccessible by other electrophysiological recording methods. For example, the presence of beta desynchronization in the frontal lobe extended beyond the primary and secondary motor cortices more widely than previously described.
significance. Our classification revealed prominent time-frequency patterns also observed in previous studies using non-invasive electroencephalography and electrocorticography, but here not yet associated with movement. We identified these patterns in brain regions. This provides new evidence for the system’s anatomical extent of putative motion networks exhibiting each of these oscillatory patterns.
