Inside Neuroscience: Tuning the Brain to Music
Playing music offers a rich cognitive, motor, and sensory experience — from reading notes on sheet music and keeping rhythmic time to moving fingers along instrument keys and processing sound. Musical training can be introduced at any age, making it an attractive paradigm of study for neuroscientists interested in how the brain responds to changes throughout life.
During a press conference at Neuroscience 2013, a group of scientists presented recent findings revealing differences in the brains and behaviors of trained musicians. The event was moderated by Gottfried Schlaug of Harvard Medical School and Beth Israel of Deaconess Medical Center.
Virtuosos Start Young
Although previous studies suggest musical training improves cognitive development in children, little is known about how the age that musical training begins can change the brain.
“If you look back in history it’s not hard to notice that most of the most successful musicians all seemed to start musical training very early,” said Yunxin Wang of Beijing Normal University in China. “Is that a coincidence, or does early musical training have a permanent effect on the neural basis of music performance?”
To begin to answer this question, Wang used MRI to compare the brains of a group of young adults, ages 19–21, who had received at least one year of formal musical training. The participants included a group of musicians whose musical training started before age seven — an age when studies suggest brain maturation peaks.
After controlling for gender and total years of practice, the researchers found that musicians who started playing instruments before age seven had thicker cortical tissue in the right superior temporal gyrus (shown to be associated with auditory abilities) and in the precuneus (believed to be involved in self-awareness) than those who started musical training later in life.
“Our study suggests a potential role of onset age of music[al] training in human brain development,” Wang explained. Wang’s group is now collecting imaging data on people before and after they start musical training so Wang’s group can better track the ways that musical training changes brain structure.
Although recent studies suggest that long-term musical training promotes plasticity and reorganizes regions of the brain that affect multisensory processing, it is unclear how this affects the perception of sensory information. To assess such effects, Julie Roy, who works under the supervision of François Champoux at the University of Montreal, evaluated multisensory performance in people with 15 to 25 years of musical training compared with those with no musical training.
During an audio-tactile integration task, the study participants heard two or more quick tones while simultaneously receiving a single vibration on their finger. After brief instructions to ignore the tones and focus attention on the tactile stimulus, the study participants were asked to report on the sensation they felt at their finger.
When musicians and nonmusicians were exposed to only a single sound, both groups accurately reported they felt a single vibration on the finger. However, when a single vibration was accompanied by two or more tones, the nonmusicians described feeling multiple vibrations. Despite hearing multiple tones, the musicians continued to accurately report feeling only a single vibration.
According to Roy, the musicians’ ability to not let the auditory stimuli interfere with their perception of the tactile stimuli suggests that long-term musical training influences multisensory processing.
Music’s ability to concurrently stimulate multiple systems in the brain may improve the communication and connectivity between key regions in the brain, Roy explained. Such effects may be particularly beneficial for people with neurological impairments.
“Our research suggests that musicians have an enhanced ability to integrate sensory information, Roy said. “We believe enhanced multisensory processing [arising from musical training] may offer new and innovative rehabilitation strategies for people with sensory disabilities.”
Creativity and Connectivity
Press conference presenter Ana Pinho of the Karolinska Institute in Stockholm used musical training to examine how creativity affects the brain.
According to Pinho, imaging studies over the past 10 years have revealed several brain regions believed to be involved in musical creativity. This network includes the dorsal lateral prefrontal cortex (DLPFC), which is involved in planning and attention to actions; the pre-supplementary motor area (pre-SMA), which is involved in rhythmic timing; and the dorsal premotor cortex (PMD), which is key to understanding melody.
Curious about the patterns of functional connectivity between the regions that are active during improvisation, Pinho and her colleagues asked a group of pianists to play several short, improvised pieces on a 12-key custom-made piano while undergoing fMRI. Aside from certain instructions — such as a request to improvise a musical sample that expressed fear or happiness, or use only six notes — the investigators left parameters such as rhythm and melody up to the musicians.
After controlling for age and overall time spent playing the piano, the researchers discovered that the more improvisational experience the musicians had, the greater the functional connectivity between the DLPFC, pre-SMA, and PMD and other motor, premotor, and prefrontal regions. The findings suggest that “improvisation experience influences functional brain activity at a network level, improving efficiency in the communication between brain regions involved in musical performance,” Pinho said.
The musicians with more improvisation experience also displayed less activity in the DLPFC, the angular gyrus, and the inferior frontal gyrus — a network of regions involved with executive function — and the insula, a key center for self-awareness. Such reduced activity may indicate that long-term training leads to an automation of the cognitive processes involved in improvisation, Pinho said.
Scientists are just beginning to uncover the many ways that the brain responds when listening to and making music. However, the panelists expressed optimism that the richness of musical stimuli may one day lead to novel rehabilitation strategies to help a diseased or injured brain bounce back.
“We know that music makes us move and creates emotions … it also engages pleasure and reward systems,” Schlaug explained. “But, music making and singing have a translational component as well. Music can offer alternative access into a broken or dysfunctional system in the brain.”