A few months ago I wrote several posts about the importance of mirror neurons in the study and performance of music. Mirror neurons, as you recall, are the cells that fire both when we act and when we see someone else making the same action, and multiple studies have been conducted that specifically explore mirror neurons in musicians. But some scientists have called mirror neurons the most hyped concept in neuroscience. So are mirror neurons myth – or reality. And what difference does this controversy make to practicing musicians?
If you read the earlier posts about mirror neurons or have read other info about these cells, you may recall that these cells were discovered in the motor cortex of macaques by researchers in Parma, Italy, in the early 1990s. The neurons fired both when a monkey grasped an object himself and when he saw someone else grasp the object. No single neurons in human brains were observed, but researchers pointed to other lines of evidence to conclude that a mirror neuron system also existed in humans.
These amazing mirror cells were quickly embraced by the scientific community and by the late 1990s, researchers looked to mirror neurons to explain the evolution of language, the development of human empathy, theory of mind (recognizing one’s own mental states and realizing that other people have mental states different from one’s own), and the neural foundation of autism.
Before long, research studies were being done implicating mirror neurons in everything from sexual orientation to cigarette smoking, schizophrenia, political attitudes, obesity, business leadership, love, drug abuse, ethics, and a great deal more (including making music).
Of course these remarkable cells also caught the attention of the popular media, and just as the press proclaimed in the early 1990s that “Mozart Makes You Smarter” (although the research really didn’t say that), we’ve now seen attention-grabbing headlines such as “Barack Obama is Tapping into Your Brain,” a 2009 article in Fast Company magazine about mirror neurons, storytelling, and communication.
In the last few years, several neuroscientists have questioned both the existence of, or the function of, mirror neurons in humans. None has been more vocal than cognitive scientist Gregory Hickok, whose book The Myth of Mirror Neurons: the real science of communication and cognition was published in August. I finally had an opportunity to read it over the holidays, so, with this post, I’m finally getting to the wrap-up of mirror neurons that I promised several months ago.
Hickok studies the neural basis of speech and language and directs the Center for Language Science and the Auditory and Language Neuroscience Lab at the University of California, Irvine. Like many others, he was initially intrigued by mirror neurons, but he decided that the claims that mirror neurons provide a neural basis for language just didn’t add up.
So he began doing an in-depth study of the original Parma papers on mirror neurons and became increasingly skeptical. He structures his book around the question: how is it possible that a cell in the motor cortex of a monkey can provide a neural basis in humans for language, empathy, autism, and more?
His answer is that it cannot. In his book, he challenges many of the current ideas about mirror neurons – whether having to do with language, empathy, or autism. He explores alternative explanations of mirror neuron function in humans, and along the way, he discusses crucial questions about human cognition.
In spite of the title of the book and the many reviews indicating that Hickok has “destroyed mirror neurons,” Hickok never says that mirror neurons do not exist. In fact, he says it is virtually a given that they do exist in humans because humans can easily imitate observed actions, so there must be a neural link between observing and executing. His chapter on imitation discusses the role of mirror neurons, but also suggests that something beyond mirror neurons is needed to explain human imitation and that something is human cognition.
In the past decade, several other researchers have questioned mirror neurons in humans. Some discount their role in understanding actions of others, as does Hickok. Others suggest that they augment action understanding. They don’t cause it to happen, they make it better. More recently, the theory has been proposed that mirror neurons are a byproduct of associative learning rather than being evolutionary, that mirror neurons develop because we have learned to associate an action we observe with one that we perform.
Associative learning, however, certainly doesn’t explain why or how newborn babies mimic, or mirror, the facial gestures of another person, as Andrew Meltzoff has shown in his research with newborns. (Born to Learn: What Infants Learn from Watching Us)
One of the problems for many neuroscientists is that mirror neuron theory made a leap from monkeys to humans without single mirror neurons ever being observed in humans. Cutting open a person’s brain to attach electrodes for experimental purposes just isn’t done. So mirror neuron research on humans has been about whole systems in the brain that can be seen through imaging, not single cells that are measured directly by electrodes implanted in the brain.
However, in 2009, a team at UCLA reported the first, and I believe only, demonstration in humans of single cell mirror neuron activity. Researchers were able to piggyback onto surgical procedures for seizures that were being performed on 21 patients with epilepsy (with their consent). The patients had been implanted with electrodes to identify areas for surgical treatment. The location of the electrodes was based on medical data about the patient, so the areas where the electrodes were implanted had nothing to do with areas known for mirror neuron activity.
The patients performed a variety of tasks, and researchers discovered that there were indeed individual neurons that fired both when the individual performed a task and when he observed that task. But what was interesting was that the activity was found in two areas where mirror responses had not previously been recorded, either as single cell activity in monkeys or systems activity in humans.
So there is clear evidence that mirror neurons exist in humans, and because these were found in areas not previously associated with mirror neurons either in monkeys or humans, the researchers suggest that mirror neurons may be found in more locations in the brain than was previously thought. In fact, in the UCLA study, the neurons were found in areas associated with movement selection and with memory.
So what all this tells us is that the mirror neuron story is far from over. Any “hot” scientific discovery, as mirror neurons were, seems to invite criticism. The science behind the original research is questioned. More experiments are conducted, more probative questions, or different lines of questions, are asked, and over time, results of the original research are either confirmed and built upon, modified, or negated. It’s a process, sometimes a long one, and in the case of any studies having to do with the brain, the process usually points to the workings of the brain as being far more complex than we had initially thought. That’s the way science works.
A good example of this process involves neuroplasticity, or the ability of the brain to change in response to learning, experience, or injury. Scientists have always believed that the brain was very plastic in childhood, but until relatively recently, scientists believed that it was not possible for the adult brain to change, that it was fixed by the time one was a teenager. No more change possible.
Philosopher and psychologist William James (brother of novelist Henry James), proposed as long ago as 1890 in his Principles of Psychology that the brain is not fixed through adulthood and that it can continue to change. But the weight of scientific opinion said this couldn’t be so, and it took nearly a century and a lot of different research studies before the work of Michael Merzenich with monkeys in the 1980s and the work of Alvaro Pascual-Leone with humans in the early 1990s proved beyond the shadow of a doubt that the adult brain is capable of change. (It’s interesting that Pascual-Leone’s experiments involved teaching adults to play a simple pattern on a keyboard. And neuroplasticity is extremely important for musicians, as we’ll discuss another time.)
Neuroplasticity in adults became accepted fact, and was due, in no small part, to the development of imaging technology that allowed scientists to actually look at the brain of a living person. Sometimes science has to wait for new technology to be able to prove a theory.
We’re now seeing the beginning of this process of change with mirror neurons. A lot of research continues to be done, both by pro-mirror neuron scientists and anti-mirror neuron scientists. And although most of the reviews of Hickok’s book suggest that he has “taken down” mirror neuron theory, and the book title itself says that mirror neurons are a myth, Hickok explicitly says that mirror neurons exist in humans. He disputes some theories, raises questions about others, and suggests alternative explanations – as do other neuroscientists. It’s all part of the scientific process.
So do Hickok’s alternate theories negate what has been learned about mirror neurons and music? Not at all. Nearly every study concerning mirror neurons and music has been confirmed by, or itself confirms, research that was studying something else – not mirror neurons.
For example, original mirror neuron theory tells us that we understand actions of others because we have a template for those actions in our own brain. That also includes understanding emotions of others, because we use our facial muscles and body movements to indicate emotions.
Applying that to music, mirror neuron research tells us that we understand body and facial motions of performers, even though we may not be a performer, because we have a template for many of those kinds of motions in our own brain. We instinctively know that fast playing with more rapid movements indicates excitement, anger, passion, etc., and slow playing with fewer or slower body movements indicates calmness, serenity, peacefulness, etc. We understand from seeing the performer’s facial expressions how involved he seems to be in what he is doing, whether he is nervous, or whether he is bored.
We can attribute that “instant read” of a performer to mirror neuron research, but the research of Dr. Chia-Jung Tsay on the primacy of the visual in judging music performance tells us the same thing. Her studies demonstrated that people responded more strongly to certain kinds of body movements, facial expressions, and visual cues, and she wasn’t studying mirror neurons. She was studying judgment and decision making, social perception, and nonverbal behavior.
Nor was Jane Davidson studying mirror neurons in her points of light studies. But she showed that body movements affect what one hears in a music performance, just as mirror neuron research has done. Schumann intuitively knew about the importance of the visual when he listened to Franz Liszt in the 19th century, as did Marguerite Long when listening to Debussy in the 20th.
The mirror neuron debate, and ongoing research, will no doubt continue for years, if not decades, but there are some “truisms” about music that have been demonstrated not only in mirror neuron research, but in other research as well.
- Imitation is important in learning a musical instrument, so watching your teacher as well as many other performers on your instrument helps one to learn. This has been demonstrated by both mirror neuron research and other kinds of research.
- Studying with a teacher with whom you have a rapport also helps the learning process. Again, this has been demonstrated by multiple avenues of research.
- Listening is important in studying an instrument (or voice). Mirror neuron researchers have written about an auditory mirror neuron system in music. Other researchers have written about the importance of the auditory-motor loop. Each seems to confirm the other.
- We understand a great deal about a performance from the visual, even without the sound. Mirror neuron research indicates this, but so do the studies of Jane Davidson and Chia-Jung Tsay, neither of which had anything to do with mirror neurons.
So stay tuned. I’m sure the mirror neuron debate is far from over. As more and more research accumulates, the story may become even more complex. But it remains a fascinating story, and mirror neurons (or their equivalent) are still extremely important for musicians.