New research is expanding scientists' understanding of how the human brain processes music. We take a look at recent projects examining the interactions of music and neurology and ask what benefits this knowledge might have therapeutically or for future research.
Doctors have long known that listening to music can cause physiological changes. Lower levels of cortisol - the stress hormone - as well as better sleep and a lowered heart rate are associated with listening to music.
To this end, researchers are investigating music therapy as an alternative to anesthesia in some instances. But what is really going on beneath our skulls when our brain digests the humanly organized layers of sound that comprise music?
Recently, Medical News Today reported on a study by Dr. Charles Limb and his team at Johns Hopkins University in Baltimore, MD. Dr. Limb is a musician and surgeon who specializes in cochlear implants. But he also conducts an ongoing body of research work analyzing neurological responses to a variety of music, from jazz to hip-hop.
Groundbreaking in its scope, when Dr. Limb began this research there was little to no scientific literature on this subject.
Music as language
One recurring area of interest in Dr. Limb's work is how musicians' brains are able to compute improvisation. Using magnetic resonance imaging (MRI), Dr. Limb and his colleagues investigated which areas of the brain "light up" when jazz musicians are improvising or rappers are "freestyling."
The team's results add some scientific validation to the notion that "music is a universal language." They observed that the areas of the brain activated when jazz players are improvising are actually the language centers of the brain - the inferior frontal gyrus and the posterior superior temporal gyrus.
In fact, Dr. Limb's team found that the areas of the brain that people might normally associate with interpreting music - the angular gyrus and the supra marginal gyrus, which process semantic information - are deactivated while musicians are improvising.
The areas of the brain activated when musicians are improvising are actually the language centers of the brain - the inferior frontal gyrus and the posterior superior temporal gyrus.
The team's work with rappers has been equally illuminating.
Any fan of music will know the experience of listening to it on headphones, closing your eyes and imagining scenes - or perhaps just abstract colors and shapes - that correspond to the tunes you are listening to. The music begins to soundtrack your own private, interior movie.
Again, Dr. Limb and colleagues found a neurological basis for this. When the rappers were freestyling from within the MRI scanner with their eyes closed, the researchers observed major activity in the visual and motor coordination areas of the brain.
The brain therefore calls upon its language, visual and motor coordination machinery when imagining and responding creatively to music, even though the bodies of the participants were laid still within a scanner and their eyes were closed.
But what are the ultimate goals for this research? Dr. Limb wants to use science to solve some of the oldest and most philosophical questions about creativity. He believes his team is firmly on the right track with its MRI scanning technique, and estimates within the next decade or two he will have answers to the following core questions:
- What is creative genius?
- Why does the brain seek creativity?
- How do we acquire creativity?
- What factors disrupt creativity?
- Can creative behavior be learned?
Music as memory storage
Other researchers are using similar methods to explore more therapeutic applications for music and neurology. Ging-Yuek Hsiung, assistant professor in the Division of Neurology at the University of British Columbia in Canada, is one of these people.
Alzheimer's patients' brains lit up in a very different way when they were engaging with music from when they were engaging with spoken language.
Prof. Hsiung is interested in how music therapy might benefit patients with dementia and Alzheimer's disease. Similar to Dr. Limb, Prof. Hsiung uses functional magnetic resonance imaging (fMRI) to analyze what areas of his subjects' brain light up when they engage with music.
In the patients with Alzheimer's, Prof. Hsiung found their brains lit up in a very different way when they were engaging with music from when they were engaging with spoken language.
Because diverse areas of the brain would light up when this group engaged with music, it led Prof. Hsiung and his team to suspect that the brain encodes memories of music differently to how it encodes regular memories.
Prof. Hsiung's results suggest that when a memory is associated with music, the information that makes up that memory is stored across several different areas of the brain, rather than consolidated in one location. One interesting aspect of this, Prof. Hsiung believes, is that it would therefore take much more brain damage or degeneration to erase a music-related memory than a regular memory.
The researchers are currently investigating whether music can therefore be used to access and stimulate damaged areas of the brain. They have have had some initial success with this in stroke patients, who reported improved memory and lowered levels of stress hormones and displayed fewer symptoms of irritability and depression.
Music and 'mirror neurons'
Another intriguing new focus of neurology with regard to music - and one that went mainstream enough to be picked up by former Talking Heads frontman David Byrne in his recent bestselling book How Music Works - is the function of "mirror neurons."
Some scientists think the mirror neuron system provides the answer to how we are moved emotionally by the abstract communication of music.
Neurologists Dr. Istvan Molnar-Szakacs, of the University of California, Los Angeles, and Dr. Katie Overy, of the Edinburgh College of Art in the UK, have led the field in examining how the mirror neuron system (MNS) contributes to our empathic and physiological response to music.
The pair scanned the brains of humans and monkeys and found that, when either group observed someone performing a particular act - such as bouncing a ball - the same neurons that control the muscles required to complete that action fire in the observer as well as in the individual performing the action.
Although the observer's muscles do not move physically, this mirroring of neural activity provides a scientific explanation for empathy
Applying their findings to emotional cues, Dr. Molnar-Szakacs and Dr. Overy found that not only did the neurons controlling the facial muscles fire in an observer when they watched someone smile or frown, but corresponding "emotional neurons" also fired in the observer's brain. The researchers argue that this is what allows the observer to participate in the shared experience of feeling happy or sad - what some scientists call "emotion contagion."
The MNS is regarded by some researchers - though others are skeptical - as being an essential component of how we understand language, and provides an answer to how we are moved emotionally by the more abstract communication of music.
The MNS is described as being dysfunctional in people who have autism and is used to explain why people with autistic spectrum disorders (ASDs) are unable to accurately read emotional cues from other humans.
Despite this assertion, a 2009 study from Dr. Molnar-Szakacs and Dr. Overy reported some success in using music therapy with ASD children. "Music appears to have special significance to many children with autism," they write, "and has proven an effective method to establish an alternative means of social interaction and creative development."
Reflecting on the reasons for this, they hypothesize that if the MNS is defective in people with ASDs, then perhaps music is effective at stimulating the MNS. If so, then music therapy may be effective at improving social functioning in people with ASDs.
More generally, this research also hits on some elemental truths of the interpersonal, emotional and therapeutic benefits of music.
"We propose that it is this ability of music to communicate social and affective information and to create the feeling of 'being together' that makes it so appealing to across all ages and cultures," Dr. Molnar-Szakacs and Dr. Overy write, concluding that:
"We suggest that we begin to conceive of music only as 'humanly organized sound' and 'soundly organized humanity,' but also as shared affective motion experience, minimized prediction error, and as an extraordinary case of being together in time."