Earl K Miller

To Earl Miller, it sounded like a storm, like thunder and lightning—ominous rumbling, crackling, expansive. It was a defining moment for Miller, who had always been fascinated by the inner workings of the brain. The year was 1987, and he was a pre-med student at Kent State. His advisors had told him that if he wanted to pursue a career in medicine, he would need to gain research experience. The first time he volunteered at a lab, he heard the sounds of the brain through an audio amplifier. “The first moment I heard that sound like a thunderstorm, I thought, ‘this is the coolest thing ever; never mind medical school, I want do research.’”

Miller went on to study psychology and neurology at Princeton University, where he earned his MA and PhD. At the time, it was thought that each neuron in the brain had a particular function (i.e., each neuron did one thing and one thing only)—"like a gear in a clock,” Miller says. So, when he and his colleagues proposed a theory that neurons are capable of performing different functions at different times—"like utility players on a baseball team,” as Miller puts it—it rankled the establishment. According to Miller, he and his colleagues, with their new theory, were considered crazy. But they were right; the idea of mixed selectivity, multifunctional neurons, revolutionized the field. “Our brains have all these neurons that can take on multiple tasks, which is what gives your brain the horsepower it needs to have real high-level thought and complex action,” he explains.

‘An integrative theory of prefrontal cortex function,’ which introduced this novel theory for understanding executive brain functions, remains the fifth most-cited paper in the history of neuroscience. .”

It would not be the last time Miller’s work shattered the dominant paradigm in his field of choice. Not long after joining the MIT faculty in 1995, he collaborated on a study with Princeton University’s Jonathan Cohen to gain a greater understanding of the prefrontal cortex. The prefrontal cortex is the area of the brain most often associated with executive functions, the set of skills that allows us to control our thoughts and consequently, our actions, providing us the ability to imagine a future state and devise a plan and a strategy to make that future a reality. But if the brain has millions of multifunctional neurons, how do they work in conjunction to help achieve higher-level thinking?

As Miller explains it, “Your prefrontal cortex develops a roadmap of what it needs to do in order to get to a certain goal, and it sends that map back to the rest of your cortex and says, ‘do this.’ That was a new way of looking at the prefrontal cortex. It's a new way of looking at how executive brain functions work.” Their paper, “An integrative theory of prefrontal cortex function,” which introduced this novel theory for understanding executive brain functions, remains the fifth most-cited paper in the history of neuroscience.

Recently, Miller and his team of researchers at MIT have been, among other things, building on that seminal work. The theory they are currently exploring is that thoughts are formed by patterns of brainwaves that organize the electrical activity in the brain. They call it the “cytoelectric coupling hypothesis.” It is generally understood that our brains operate thanks to brainwaves—basically oscillating patterns of electrical fields. What we didn’t know, until Miller and his team uncovered the evidence, is that these electrical fields carry information that the brain can use to physically change its molecular structure. “It’s the first mind-to-molecules connection between information the brain is processing, and its molecular scaffolding. This allows the brain’s own thoughts to tune its networks in order to process information more efficiently,” says Miller.

My work primarily focuses on the role of brainwaves in producing thought, cognition, and consciousness. We study how these patterns of brainwaves traffic thoughts around your brain and make consciousness and thought happen.

With mounting evidence that many psychiatric disorders physically alter brainwaves, the discovery has significant implications for treating disorders like ADHD, autism, and schizophrenia. “We’re working on new methods for closed loop electrical stimulation where we actually read the electrical signals from the brain and push the brainwaves around a bit, change them. If we can figure out how to realign the brainwaves and let the brain learn with its plasticity to stamp in that realignment, we could potentially treat a lot of diseases,” Miller explains.

Today, he says, “My work primarily focuses on the role of brainwaves in producing thought, cognition, and consciousness. We study how these patterns of brainwaves traffic thoughts around your brain and make consciousness and thought happen.”

He is still fascinated by the inner workings of the brain, still recalls the sound of thunder. But Miller says he wants his research to have real-world impact. He recognized an opportunity when he and a former student discovered that humans don’t perceive evenly across our visual field, and the cognitive capacity for perception varies from person to person. “We’re not talking about sharpness or acuity like with eyeglasses,” says Miller. “It's about awareness; what you consciously perceive. It’s about how and where things reach awareness deep in your brain. Some people are aware of twice as much stuff in the upper left vs lower right of a visual scene. Other people, it's the opposite. It varies highly from person to person.”

This new understanding of human perception inspired Miller to co-found the MIT-connected startup Splitstage. Using specialized behavioral testing, SplitStage generates a “heatmap” to demonstrate where each person is better or worse at perceiving things in their line of sight. It also functions to assess general cognitive function, and has potential applications across areas like sports training, military training, and medical diagnostics. Right now, Miller is working on a theory that could benefit people suffering from autism. It starts with the understanding that the sensory overload that occurs when autism is present is the result of a brainwave imbalance. As Miller puts it, “The low frequency control brainwaves are being overwhelmed by the sensory inputs flooding into the brain. We're working on a model so we can strengthen those control frequencies, strengthen those brainwaves that produce the control, that filter out the unwanted sensory information, and restore the balance.”