(Graphic courtesy Peggy Mason)

Free thinking

Neurobiologist Peggy Mason gives almost 55,000 students an online introduction to the brain.

Toward the end of week seven in Peggy Mason’s online course, Understanding the Brain: The Neurobiology of Everyday Life, the University of Chicago professor introduced the concept of self-generated movement, “where neurobiology and philosophy meet.” The subjects intersect because movements that fall into the self-generated category are open to interpretation.

Reflexes, which the spinal cord predominantly produces, tend not to be considered self-generated. The same goes for stereotypical movements, the standardized processes that all healthy humans automatically learn to perform, such as walking and chewing.

But there’s a third type of movement, originating in the forebrain, the anatomical source of self-generation. Within that category there are two subtypes: volitional and emotional movements.

Volitional movements include the fine motor control required for writing, turning a page, or playing a musical instrument. They also encompass facial expressions, speech, and gestures. “There are descending pathways,” Mason said, “that go from the forebrain to the brain stem and the spinal cord to produce either volitional movements of the appendages, the limbs, or of the face, the upper airway, the tongue.”

But not all movements originating in the forebrain are deliberate. There are also those defined as emotional movements—instinctive reactions like smiling and frowning, even posture that reflects our feelings. “We embody our emotion,” Mason said. Like volitional movements, emotional actions originate in the forebrain, but they follow different, still largely uncharted neural routes. A lesson in those mysterious pathways created a startling illustration of the nervous system’s complexity.

Mason displayed a series of photos of a stroke patient. A doctor had asked the woman to smile and she could move only half her face, the right side remaining slack. But when she reacted to a joke, a smile spread across her entire face, the stroke damage undetectable in her expression. The same thing held true when she grew frustrated with the doctor’s orders. No impairment prevented a symmetrical and unmistakable look of exasperation.

The pathways that her conscious movements travel had been damaged by the stroke, but the neural trajectory of her emotional actions remained healthy. “An individual who has an inability to produce volitional movements in response to a command,” Mason said, “has complete ability to do the same movement for some other emotional reason.”

I don’t remember my exact reaction to that information—Mason also explains how we edit memories in the retelling, so any recollection would probably be imprecise anyway—but I must have responded with emotional movements expressing surprise, a common response from me during the intriguing introduction to neurobiology.

The free, noncredit online course grew out of the University’s relationship with Coursera, a provider of massive open online courses (known as MOOCs). Coursera offered its first two UChicago courses in 2013—Global Warming with climate scientist David Archer and Asset Pricing with Chicago Booth finance professor John Cochrane. This year the University also joined an online education consortium called edX, a platform developed by the Massachusetts Institute of Technology and Harvard University.

Two faculty committees recommended allowing interested professors to experiment with online education. The UChicago-based courses, although still few in number, reflect different motivations among faculty. Archer, for example, has described his MOOC as an extension of his public outreach to educate people about climate change.

Mason, author of the textbook Medical Neurobiology (Oxford University Press, 2011), calls herself a “neuro-evangelist,” which makes Coursera her megachurch. Her infectious preaching made me a believer in online learning itself, which appealed to Mason as a form of “educational social justice.”

Designed for the general public, Understanding the Brain required no prerequisites. Each week included a series of video lectures that could be absorbed whenever time permitted, convenient for the nearly 55,000 students enrolled, but challenging circumstances for a professor to attract and maintain their attention.

During the first few weeks of recording this past January, Mason did not feel invigorated like she usually does after teaching. She sensed that the lectures, essentially repackaged from her med school course, would not connect with the target audience that producer Emily Joy Bembeneck had described: people who were eating dinner, doing the dishes, or otherwise distracted by life.

On a train ride home in late February, the conductor mentioned to Mason that he had registered for the course. “I couldn’t sleep that night,” she said, recalling the nagging thoughts that kept her up. “This is so not going to work for Jeff. It’s so not right.”

After meeting with Bembeneck, who works in the University’s academic and scholarly technology services department, six weeks of recordings went into the trash. The rush to replace them before the course went live in April came with reassurance: the crew’s once blank expressions showed increasing understanding and interest. “Then I was completely energized,” Mason said. “A totally different feeling.”

The student response energized her even more. Discussion forums were lively, quizzes and final projects impressive. And, Mason said, she would sometimes get more emails in a day than Bembeneck told her to expect for the duration of the course.

I took in only the video lectures, often bingeing to keep up—online education illustrated, all too well, the notion of self-generated movement. But the information was interesting and accessible enough to be digestible even in much larger quantities than the intended bite-sized portions.

There was, for example, the revelation about fever. I always believed the chills that accompany a high temperature were the body’s cooling mechanism. Not so.

The hypothalamus, Mason explained, holds our body temperature “rock steady” at 37 degrees Celsius under all external conditions. Stepping out into the cold, for example, creates a sensory response that prompts changes that maintain our inner warmth. “Your skin temperature would change,” she said, “but the hypothalamic temperature would not change.”

That unwavering level is called the set point. A fever happens when the hypothalamus changes the set point to fight an infection. And the chills come from the body’s lag in increasing its temperature to the new set point, perhaps 40 degrees. “Before we got sick, when we were at 37 and the set point was at 37, we felt comfortable,” Mason said, illustrating a new set point and the body temperature’s delayed rise with a marker on a whiteboard. “Now we’re at 37 or even 38, but the set point’s at 40. What do we feel? We feel cold.”

Nuggets like that studded the video lectures. Hovering over it all was the spirit of Jean-Dominique Bauby, author of The Diving Bell and the Butterfly (Knopf, 1997).

After suffering a massive stroke in his brain stem, Bauby was left paralyzed and tethered to a respirator, unable to breathe or swallow. His incapacitated condition, called locked-in syndrome, left him with only a single working eyelid.

With assistants pointing to or reading from an alphabet, Bauby cobbled his book together by blinking each time they arrived at the letter he wanted.  “With the one avenue that Bauby had to express himself,” Mason said, “he did.”

His achievement served as an introduction to “the power and the profundity of what our nervous system does,” after which Mason spent ten weeks detailing the physical and emotional ways the brain moves us.


Over ten weeks Peggy Mason’s free, noncredit online course Understanding the Brain: The Neurobiology of Everyday Life covered three main topics: neuroanatomy, neural communication, and neural systems. With video lectures and labs, discussion forums, and quizzes, the material was structured in weekly units such as voluntary movements, homeostasis, and executive function. The estimated time commitment was four to six hours per week. Weekly quizzes made up 75 percent of a student’s grade while the final project—to illustrate a personal example of everyday neurobiology in an essay, slide presentation, or video—accounted for 25 percent.


A behind-the-scenes look at Peggy Mason recording a lesson video for her online course Understanding the Brain: The Neurobiology of Everyday Life.