Scientists at Brown, including doctoral Neuroscience student Hyeyoung Shin, have found that people and mice alike use brief bursts of beta brainwaves, rather than sustained rhythms, to control attention and perception. To better understand the brain and to develop potential therapies, neuroscientists have been investigating how “beta” frequency brainwaves help the brain filter distractions to process sensations. A new Brown University study stands to substantially refine what they thought was going on: What really matters is not a sustained elevation in beta wave power, but instead the rate of specific bursts of beta wave activity, ideally with perfect timing.
The new insight, reported in the journal eLife, arose from the scientists looking beneath the covers of the typical practice of averaging beta brain wave data. With a closer examination, trial-by-trial for each subject, they saw that what really reflected attention and impacted perception were discrete, powerful bursts of beta waves at frequencies around 20 hertz.
“When people were trying to block distraction in a brain area, the probability of seeing these beta events went up,” said senior author Stephanie R. Jones, an associate professor of neuroscience at Brown. “The brain seemed to be flexibly modulating the expression of these beta events for optimal perception.”
The findings, made with consistency in humans and mice, can not only refine ongoing research into how beta waves arise and work in the brain, Jones said, but also provide guidance to clinicians as they develop therapies that seek to modulate beta waves.
The research team, led by Shin, acquired the data through a series of experiments in which they measured beta waves in the somatosensory neocortex of humans and mice in the second leading up to inducing (or not inducing) varying amounts of a tactile sensation. Humans wore a cap of magnetoencephalography sensors, while mice had implanted electrodes. For people, the sensation was a tap on a finger tip or the foot. For mice, it was a wiggle of a whisker.
Read more of David Orenstein's article about beta brainwaves.