The scientists hope that these sound waves will help them gain a new perspective on how the brain works.
During the sleep symposium, Janna Lendner, an anesthesiologist at the German Medical University Hospital, presented a study aimed at neurological treatment.
Specifically, Lendner found that when a person is asleep or in a coma, their nervous system relaxes and perception begins to distort . From there, they produce abnormal brain waves . She thinks these are signs that help people better understand how the brain works.
Up to now, the human brain still has mysteries that humans cannot fully understand. (Photo: Irish Central).
Some scientists at the conference said it would be difficult to delve into this issue. The reason is that when a person is dreaming, also known as REM (Rapid Eye Movement) sleep, their brain waves fluctuate similar to when awake. Therefore, it will be difficult to detect the difference.
However, Dr. Lendner insists the answer lies not in the brain waves themselves, but in an aspect often overlooked by scientists: the abnormal sounds produced by the brain’s electricity.
The doctor thinks that these sounds contain some secret signal that humans have not yet exploited. “Any sound can be a clue,” she said.
Many people are still skeptical about this theory, so they have reached out to Mr. Bradley Voytek, a cognitive scientist at the University of California (USA). They argue that brain sounds are not worthy of study. However, Voytek found that scientists were missing something important.
Previously, Voytek had studied the changes in brain electrical sound as people age. Then, based on his research on abnormal brain activities, he had a basis to believe in Lendner’s argument.
He spent years collaborating with scientists at the University of California at San Diego and Berkeley to develop software that helps extract consistent neural oscillations, such as alpha waves. The returned results can be observed in the form of a spectrum to help display many waveforms, including sound waves.
“Simply meeting scientists and saying ‘we’re lacking’ is not enough. They need a real research methodology,” Voytek said.
Lendner believes that finding the pattern of acoustic signals in the brain will become an important contribution to neuroscience. (Photo: Wired).
Voytek’s software has made it possible for scientists to analyze the role of brain waves in human behavior, cognition, and even incubation. Voytek calls the phenomenon he’s studying “signal inconsistencies”.
In 1925, scientists also discovered abnormal fluctuations in the brain’s sound waves. However, due to equipment limitations, scientists at that time could only consider this as an unexplored law.
Now, thanks to Voytek’s algorithm, they have a better tool to analyze these inconsistent signals.
They are consistent long-term activities, like breathing and heart rate, that keep the body alive.
For example, when neurons secrete an acidic compound called glutamate , the brain produces a feeling of excitation. Conversely, when neurons produce gamma-aminobutyric acid (GABA), the human nervous system is inhibited.
If the above two compounds are secreted without following any rules, our body will suffer certain reactions. Over-stimulation will lead to convulsions. Meanwhile, increased inhibition will lead to coma.
However, Lendner, Voytek and many other scientists believe that the brain has a non-periodic oscillating brain waveform.
“It’s random, but there’s a lot of randomness in the world,” says Voytek, implying the special need for attention of abnormal brain sounds.
Based on the EEG information, Voytek found that different neurological states also produce different waveforms. For example, the period of alpha wave oscillations during sleep is 8-12 Hz.
Thus, abnormal sounds in the brain must also be associated with a certain state.
Using Voytek’s software, Lendner and his colleagues found that the small amounts of sounds produced by the EEGs of comatose patients were heterogeneous.
Spectrograph showing brain activity of a sleeping patient taken by Lendner. The amplitude of the white sound varies based on the patient’s cognitive state during sleep. (Photo: Wired).
Lendner’s research shows that these audio cues act as a “unique signature” for measuring human consciousness. This is key to improving anesthesia and treatment for comatose patients, Landner said.
According to Voytek, older brains are dominated by white wavelengths more than younger brains. He suggests that these sound amplitudes are linked to aging memory decline.
Another study also used Voytek’s electroencephalographic algorithm to investigate the effectiveness of ADHD medications. Along with that, it serves the purpose of studying the brain of autistic people.
Natalie Schaworonkow, a PhD student at Voytek’s lab, also used his software to analyze the EEG data of a newborn baby. Accordingly, they found that during the first seven months of life, inconsistent signals changed significantly and they increased gray matter in children.
However, Schaworonkow says more research is needed to see if these wavelengths also affect other aspects.
According to Wired, having a tool like Voytek’s software is important. Neuroscientists can check the brain’s signatures just by observing the sound signals emitted.
Currently, the limitation that scientists face is that no one knows exactly what causes these signals.
“Their cause and origin are yet to be determined. But we have to keep studying to accumulate knowledge,” said Sylvain Baillet, a professor of neurology at McGill University (Canada).
To test the hypothesis about the origin of the inconsistent signals, Voytek says, we need to find out what kinds of neural circuits might be generating them. Then, link them to overall brain activity to predict signaling mechanisms.
According to Wired, in the future, these inconsistent signals will greatly assist humans in learning more deeply about how the brain works.