Brain Waves

Brain stimulation, which utilizes a low dose of electric current, could lead to new therapies for neurologic and mental illnesses.

CHAPEL HILL — “Let me know if something is uncomfortable, because you’re going to feel a bit of pressure,” says Dr. Flavio Frohlich, Assistant Professor of Psychiatry, Cell Biology and Physiology, Biomedical Engineering and Neurology at the University of North Carolina at Chapel Hill School of Medicine.

His question came from behind me but I couldn’t turn to answer. That’s because graduate students were fitting a tightly stitched net filled with electrical sensors around my head.

“Would you mind if I shared this on social media right now,” Dr. Frohlich added, laughing. 

“No,” I replied, but then added, “But you can’t imagine just how weird this feels.”

The net of 128 sensors, or electrodes, is used in groundbreaking research to record the brain’s activity near the surface. But researchers aren’t only interested in seeing what the brain is doing. The ultimate goal is to understand the brain’s activity and then talk to it.

“We’re trying to speak the language of the brain, which is really electricity,” explains Dr. Frohlich. “And once we do that we can develop novel brain stimulation approaches to treat disorders such as schizophrenia and depression. But first we need to speak the right language, and brain cells use electricity to talk with each other and so we are also using electricity.”

The sensors allow researchers to pinpoint specific brain activity in the cerebral cortex. That’s the brain’s outer layer. It’s the most highly developed part of the brain, and it’s where the brain processes most of the information it receives.

The cerebral cortex is divided into four lobes and each of those lobes has a specific function.

The frontal lobe is involved with decision-making, problem solving and planning.

The parietal lobe processes sensory information such as smell and touch.

The occipital lobe handles vision.

And the temporal lobe processes memory, emotion, hearing and language.

At the center of the research is the understanding of neural oscillations. Those are the electrical patterns the brain uses to communicate and process information. The wave forms differ from patient to patient and by what the person is doing. Once researchers identify the signals associated with the activity they are interested in, they can learn the language and talk to the brain.

“We pick up the electrical signals in real time,” says Dr. Frohlich. “And depending what we detect, we then decide how to stimulate and target these rhythms.”

This method of talking to the brain is called transcranial current stimulation. It uses a very weak electrical current—one to two milliamps—that’s roughly the power produced by a 9-volt battery. Dr. Frohlich says his team isn’t overriding what the brain is doing, but they are adding to the conversation.

“The first thing we do is listen in and see what brain is doing,” Dr. Frohlich explains. “And then enter dialogue and say for example, we like this so do more of this, but not this. It’s really a gentle way of creating a dialogue with the brain and its activity.”

The challenge for researchers is that the brain’s activity isn’t easy to understand. It isn’t the traditional wave line that goes up and down in easy movements. Because the brain is processing a lot of information at the same time, a map of brain waves more closely resembles a lot of jagged lines, some narrow and some wide, scribbled all over a piece of graph paper.

But, if the brain’s rhythm patterns can be understood, those patterns can be enhanced to help people with depression, schizophrenia, and other conditions.

“The key to this research is that you have to learn what it is that keeps someone stuck in a state, and then tell the brain, through synchronized neural firing, that we want you to change what you are doing,” says Dr. David Rubinow, Chair of the Department of Psychiatry at the UNC Chapel Hill School of Medicine. He and Dr. Frohlich are collaborating on a study to use brain stimulation in two clinical trials to treat patients with major depressive disorder.

“We tell the brain we don’t want you to be stuck in this combination of neural computations that we experience as feeling and thoughts and we want you to shift that, and the program you use for interacting with the world is going to be a different one,” adds Dr. Rubinow.

Preliminary results from experiments are promising. Researchers are planning larger clinical trials going forward.

“The sophisticated form of non-invasive brain stimulation where we listen to the brain and in a targeted individual way alter brain activity... We have first studies that came back positive in restoring brain function and that’s why I’m very optimistic,” explains Dr. Frohlich. He pauses for a minute, smiles and then adds excitedly, “If we can manipulate brain activity and restore their cognitive function that would have an amazing impact in these patients lives.”

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